Build your own Stair Lift.

Build your own stair lift for under 150 pounds.

Disclaimer. If you live in the western world, then you cannot use this design. Lawyers will prevent you having a better life due to the increasing fear of litigation.
If you are pissed off with the way that lawyers are ruining the world for ordinary people, then don't vote for freemasons, lawyers or burEaUcrats.
Britain is a terrible mess, where lawyers run (and ruin) the country and look just how stupid modern British life has become. Some councils spend more for law suits from people tripping on bad paving, than they spend repairing the paving. A world gone mad from increasingly parasitic and incredibly rich lawyers.
If you live in such a strange and sick world, frightened by a plague of lawyers, you may simply wish to use the lift purely to lift very heavy plant pots about your own weight and size or other items. But using it for carrying yourself is going to upset lift manufacturers and their lawyers too, due to safety concerns of not having the right paperwork. Of course, some people may wish to say 'sod off' to lawyers and their increasingly restrictive ways. I cannot condone this, as everybody must live safe, cosseted, and subsequently boring lives.
Therefore if in any doubt about safety or legal concerns, or the EU monstrosity, or Blair and his Cronies, then you must not read this and you must not act upon it.

If one day you wish to have your own opinions, then you may want to use your vote to keep lawyers away from politics. Always vote, even if you have to spoil your vote because none are decent enough citizens.

Why make a stairlift.

So being poor and unemployed, and wishing to keep some self respect, I decided to build one for my mum, and probably for myself in a decade or so, as I'm 55 yrs old. I went to others who were not so disabled as my mum, and inspected the designs my city council fitted for those who knew someone in government or had the dodgy handshake, and thus got what they wanted from the taxpayer. (Please note: Inequality never makes for a happy society. So if you are a lawyer, freemason or politician, then you are not welcome to this website. I denounce freemasonry and other such clans which destroy any chances for a nicer society.)

The stair lifts fitted by the council to others we know were very expensive, very well built, very slow, very bulky and very obtrusive. The people who got them had no choice in what is available and subsequently they could only use taxpayers money for what was available. I was not impressed with any of the designs. I decided I could do much better for less, would also save the taxpayer thousands of pounds.
The taxpayer is definitely being ripped off.

The design described here is narrower, faster and cost less than two hundred pounds, although I did borrow a 40 quid welder and scavenged a few bits and pieces.

The commercial stairlifts that are available, all take up vast amounts of room and are ugly in a blatant 'designer' way. If you are to have an ugly device, at least make it compact and out of the way. The less you see, the less obtrusive it is. Making a big, flashy stairlift which gets in the way is not good design, even if the designer thinks it looks pretty.

I consider that any stairlift should be almost invisible, or at least as compacts as possible, which is something all commercial manufacturers seem to have completely forgotten.
Making it yourself can also allow you to customise it further until it fits in with minimal obtrusion.

This project is being done during the sickly named 'British Innovation week'.
There is no innovation in the project, as this is simple technology. True innovation would be making people realise that they need not spend 6,000 pounds on a fancy stair designs which waste taxes.

From an engineers point of view (I used to be a member of the institute of plant engineers for my sins), most stairlifts are a 'rip off'. They are superbly made and built, but the costs required for fancy technology is high. As an engineer looking at the designs, the true cost for such engineering would be about 1,000 or perhaps 1,500 pounds maximum. Plus about 150 pounds for one man for one afternoon for installation.
Don't get ripped off.
If you cannot build your own, get a second hand one. Always haggle as hard as you can, as you should be able to drop the price by at least half.
A friend's mum squandered her life savings by not haggling. She could have saved herself almost three thousand pounds. The salesman probably got an extra bonus and the boss probably has a new motor yacht or mercedes.
My friends' mums stairlift failed and they needed to replace the battery. The stairlift firm charged her 95 pounds. My friend uses the exactly same battery for starting his model aeroplane engines and glow plug. It is a very common 12 volt gel battery available almost anywhere. The very same battery cost him 15 pounds.
You WILL be ripped off by stair lift manufacturers.
Tax payers are.

Fancy technology is not needed to lift a person up stairs.
There are many ways as mentioned later, but the basics of stair design is very simple technology.
If you want to build your own, then glean what you can from this and see how easy it is.

Why do people spend 6000 pounds when you can get a better design for 200? Because that's the way people are taught to think nowadays. As an unemployed technology teacher (gizzajob), I try to get people to think, then do it themselves, but anything approaching engineering seems too difficult nowadays.
As a British bloke with a B.Ed, B.Sc and engineering qualifications, I see this all too closely and the plain demise of once great Britain. Even changing a tap washer is simple, yet people pay 60 pounds to have a dripping tap repaired. If you prefer to 'do it yourself', then have a go. There is a lot of this kind of stuff on my website.

By trying yourself and failing, you may loose up to fifty pounds. To check such a test rig stairlift design before paying the cost of the winch, simply test the basic system with a strong person pulling. If not happy, you will have lost time and a little money. - But at least you will have tried.
Alternatively look around for second hand stairs, the owners of a house may be only too happy for you to cart it away for 500 pounds, so ask around first and look in the papers. Some people will fit second hand stair lifts for a thousand pounds or thereabouts.

There is nothing difficult in stair lift design. It's not simple, but neither is it rocket science. Any house needing stairs is capable of a lift of some form. This monograph describes building but one, with other design options later in the monograph.

As the reader will be building to their own design, then the design process is kept simple, with just a few subtleties and the background to the thought processes included, so the reader can adapt these to suit their own needs. I have gone into detail and in some cases repeated areas where needed. (Better too much than too little information. )

Walls.
WARNING: Check the condition of the side wall, as not all walls are designed for side pulls and it is best to be safe from the outset. Only bad architects, ancient buildings or 'designer' homes may have lightweight walls beside stairs.
Look for thin walls or lath and plaster or even wattle and daub. Only when absolutely certain that the wall is strong enough should you continue. If the wall is not secure enough, then it may be possible to reinforce it, but only if the rest of the house structure is applicable.
If the walls do not have bricks and cement, then consider using strong wooden beams secured to the presumably strong parts holding the stairs in place and up to the ceiling beams. These are best set into the wall, by paring back any weak wall areas, then plastering after the stair lift testing process is complete. If no wall is in place, then you may be able to position and secure a large wooden beam up and parallel to the stairs to make a secure hand rail and upper rail mounting.
If the wall is very frail or weak, then drill through to the other side and place large reinforcing steel or plywood sheets to take the load. Alternatively, build the bottom rail out from the wall far enough to take the full load centrally over the bottom rail, such that there is minimal load on the wall from the upper rail.
In most well designed houses, the stairs are mounted next to a main structural wall of the house.
Wall Test.
Take time to have a look at your wall: Drill a hole, fill it with a plastic plug to take a strong screw and fit a block of wood with a loop of webbing behind the block to make an impromptu handle, then try to pull the fixing off the wall.
If the house is very old, be it mansion, arched Georgian esplanade or merely a tenement, the walls may have been built from rubble, so there may well be some weak areas and some strong areas. To find the strong areas, drill lots of little test holes until the masonry drill finds something hard, such as a rock or small boulder.

The skills.

As a teacher, I do not recognise disability as a problem, but a chance to improve oneself. The hand tools can be used if in a wheelchair, although this will take a bit longer. Fitting the rails may need help if wheelchair bound, but shuffling up the stairs on your bum with strong arms and an electric drill will allow success albeit with some effort.

Always ensure the use of standard safety equipment such as goggles for power tools and welding protection must always be used.
Time to design, build and test is about 20 to 80 hours, depending upon abilities.

Tools.

An arc welder, about 130 amp will be quite adequate, which cost from 40 pounds or can be hired. Ask around first, as many unemployed or retired people have such equipment and they also have the welding skills required.
Hacksaw and an 8 inch half round file.
Electric drill and drill bits. The drill should be a hammer drill as this will allow drilling into a stone wall for the handrail mountings.
If you buy all the tools including an arc welder, then you should get change from 70 pounds. This assumes you use a cheap tool shop, and have no pretentious needs.
Only a bad craftsman or woman blames his or her tools. (This 'political correctness' is getting stupid. A craftsman from now on is anyone who has craft skills, irrelevant of gender or sexual orientation, religion, hairstyle or other twaddle. )

Materials.

Two (or four - see later) 6301 ball bearings or similar. Although anything around this specification will suffice.
If no bearing shop nearby, simply buy them from your local motorcycle shop or salvage from old motorcycle wheels. Keep the old wheel spindle as this also makes an excellent mounting spindle. Any rusty old motorcycle or (scooter front wheel) will suffice, as their wheels are designed to support the weight of a rider and luggage and do so at high speeds. You could probably get a pair of buckled or rusted wheels for a couple of pounds. Do not buy bearings from a bearing shop, unless no other options, as they often charge exorbitant prices. (They do in Plymouth !)
Some 12 mm dia bolts or a length of 12 mm dia stud bar, washers and nyloc nuts. Stud bar is simply a yard length of threaded bar which can be cut to length and available in any DIY shop.
A long length of flexible 13 amp three core electrical cable suitable for a heavy appliance such as a heater or kettle.
Nylon tie wraps.
A couple of electrical switches, and a couple of connectors as needed. See later.

If you buy all the materials then you should get change from 50 pounds, excluding the winch. About 30 pounds for the tubing, and six quid for the cables, and ten quid for the switches.
Suitable winches have recently dropped from 120 quid to 80 but the manufacturing plant may have moved from Italy to China, so be very careful about quality and reliability.
If in doubt, consider fitting a better winch once the first build has proved the working design as suitable for your needs.

Once you have the basic lift working, then you can splash out a little cash on the power winch.
An electric garage hoist, of at least 100 kg lift capability.
Or some other motive means, see later :)

A little basic arithmetic.

In reality, most winches in this range are designed for lifting car engines in garages, or for fitting to the front of silly 4x4 cars for pulling them out of swamps when they get stuck. (Farmers Land Rovers excepted, being genuine off road machines, the rest merely being 'Twattle trucks' or Bimboy vans.)

As will be seen, most of the winches available will be way above the requirements. Looking through many of the catalogues available to most people, such as tool shops and car accessory brochures, the choices will be plenty good enough. To be safe, never drop below a pull of 100 kg, as this gives a good safety margin of over 200 percent for most situations.

Do not spend more money on an expensive winch. - Even a cheap winch which is going to have a lazy life, so will also be a reliable winch. A cheap winch which is easily available is also a good choice for the next ten years should the winch need replacing for another cheap winch rather then consider repair or other hassles. So always consider 'repair by affordable replacement'. For such reasons, the winch mounting is kept very simple, so any suitable cheap winch can be used in the unforeseen future. When replacing with a standard, generic winch of a globally available, very commonly used design, then the builder has the old worn winch for close inspection for future assessment; A spare machine to strip and inspect for potential improvement and for avoiding similar long term failures. Plus some spares and the chance to understand how to repair it next time.
The common choices of winch will usually offer a double safety factor and can even be used for the vertical lift design.

Two types of winch, mains or battery.

12 volt.
Choose 12 volt with battery if living in a country with a poor power supply, as this allows you to move even in an emergency. But this involves a battery and charger etc. These winches are those used on the front of off-road cars.
If fitting the winch under the seat, then the 12 volt option is best and the safest.
12 volt systems can operate with a car battery trickle charger off the mains wiring. They can also be backed up by a (yacht) solar panel charger. But batteries fail with time, so simply replacing a decent car battery for about 30 pounds every three years is cheap maintenance and good for reliability.
Also use 12 volt electricity if using the stair lift outdoors, or where rain can reach the components. Warning: Using mains electricity outdoors can cause electric shock unless expensive waterproofing is done.

The battery can be the smallest and cheapest car battery, or perhaps a large motorcycle battery, if not too expensive, as it needs only work for a minute or so. Ask at your local car shop for suitable battery and charger choices, then choose the cheapest with the largest AH capacity.
I would seriously recommend a standard car battery, as these offer massive power for little cost, giving good storage and low running costs.
If you have a car, then get the battery changed and keep the old one for test purposes.
Choose an intelligent battery charger if you are rich, or just a really small, basic charger as this will be perfectly adequate, as this will allow you to buy two cheap chargers, one for reserve or both working with redundancy. Some chargers have lights showing the state of charge.
A charger costing about a tenner should be more than sufficient, or a very cheap UNregulated 12 volt charger for a domestic item can be used, if not using the lift every hour.
Even a solar panel, or anything which keeps the battery topped up with a trickle charge.
If the lift is being used every five minutes, then use a 5 amp car battery charger.
If used about four times a day, then a small trickle charger will suffice.

I don't even use this, as an old (unregulated) chargers for many different 12 volt domestic items such as table lights, electronic toys, computer printers, drill chargers and such like. My little 3/4.5/6/9/12 volt charger cost 4 quid new, which is fitted to a three quid 24 hour timer to charge up the battery every morning and evening for an hour or two. It really is that simple. (I've added cooling holes to the plastic casing of the charger, as the cheap versions tend to fail from overheating of the transformer coil.)
See also the battery monograph on my website.
Do NOT use a 12 volt regulated power supply. A battery needs 13 volts or more to charge up. Placing 12 volts across a 12 volt battery will do nothing. A cheap 12 volt UNregulated charger will always rise above the 12 volts, so that electricity can flow.
All proper 12 volt battery chargers supply about 13.5 to 14 volts.
(For the electrically minded. If you have a surplus 12 volt regulated supply and are an electrician, then simply by - pass the regulator section and use unsophisticated, rectified DC power from after the four diodes. )
If choosing the 12 volt option, the best battery chargers are the smaller intelligent slow chargers which will give constant trickle charges and allow the lift to be used many times without mains electricity.
About 30 pounds should suffice for a cheap car battery. Batteries can also be found second hand in scrap yards for testing purposes, so you don't spend any more money than you need. Remember; this monograph is aimed at the British poor, who are far more prevalent than Blair and his tax grabber friends may think.

Mains electricity.
(240 volts AC in the UK, 120 volts AC in the USA.)
If living in a country with reliable power supply, then use a mains powered winch. This is often cheaper and more reliable. Mains electrics eliminates the hassle of batteries and chargers. There is no battery to change every four years or so, nor any charger needed.
There is a problem of the high voltages with mains power, but careful routing of simple switches is straightforward.
Remember that if your power supplier is unreliable, then mains electricity is not to be used if there is any likelihood of failure part way up the stairs.
The mains powered garage winch is also much faster at 11m /min, so it does not take for ever to get up them stairs.
Always remember that mains wiring will need to be carefully done, as this is capable of delivering a serious electric shock.

Nanny State warning:

For all other peoples of the free world, the chosen design will depend upon how much you wish to spend.
A second hand winch, two nice long lengths of new tubing and some scrap metal will furnish a lift of sorts. (Although preparation to get the materials to a desired standard may require welding scrap tubing together to make the long rails, if really poor.)
The rest of the design can be made from simpler and very common scrap metal. Perhaps some old bed rails or a metal table frame and a discarded office seat as a starting point to test the basic design.
A 20 foot length of square tubing costs about a fiver, a welder about 40 quid, a winch about 70 quid; so don't skimp of the important bits.

The design considerations.

In this example, the problem was a very narrow staircase, with the obvious need for minimal obstruction.

The distance of the bottom rail off the wall was limited to 7.5 inches, (190 mm) to allow reasonable pedestrian use, which left some working room for a moving seat which would not obstruct the banister (hand rail). Being able to keep it narrow and compact, makes the professional designs look bulky and ugly and of course, more difficult to live with than simpler designs. This home made stairlift is not a 'designer style', but at least it is very unobtrusive.
The commercial stair lift in a friends house with far wider stairs, still manages to be far more intrusive.

If a very heavy or large person, then special considerations are important from the outset. If over 12 stone, 70 kg, consider a stronger winch to maintain a good safety factor. I used a winch with a cheapo 125kg pull for testing with 15 stones (82 kg) which needed a safe 65 kg lift force.
If a large person, then the seat must be ergonomically suitable and lots of testing in the sitting position will be needed to ensure safety in all situations.

The example shown is for an old person of 8 stones, but tested by me who tested it while also carrying my heavy tool box, to about 25 stones.

No calculations were done other than the lifting force. The rest is by rule of thumb and looks a little overbuilt rather than perfect for the theoretical designer.

Once built with a 8 stone load, (50kg) the lift was test lifted with a measured pulling force of 35 kg.
With a 15 stone rider, (95kg) the pull needed was 68 kg.

While heavily loaded, the structure was checked for significant deformations and misalignments, but none were found. (See also testing, later.)
A final check that the machine was not being overloaded was to replace the fitted 13 amp fuse with a standard 2 amp fuse, which did not blow, showing the winch was not remotely approaching its 500 watt power capability.

The design shown has a pair of rails.

Good design should be simple: This winch pod is also easily removed and stored when the lift is not needed.
Once the lift unit is removed, then unscrewing the bottom rail leaves the stairs with a simple handrail in just ten minutes.
The removable winch pod allows it to be simply removed to the workshop many times with relative ease. This enables the builder to modify the mechanism until perfect.
The winch pod was also eventually shimmed with wood strips for a snug fit to the wall and floor, then screwed in place to the floor once all was working properly.

If you have no wall, or suspect the wall is not strong enough, then the ideal is two rails to tale the seat unit. Unfortunately , this can male for the rail being too far into the walking area of the steps, so a compromise may be needed, such as a single load rail, and an inner stabiliser rail.
For a stabiliser rail system, you can place two widely spaced rails on the steps, the outer rail to be directly below the centre of the seat. The inner rail will be there to balance the seat and stop it from tipping over. The inner rail will need to be set an inch or so above the stairs, so that a retaining slider can fit underneath to prevent the seat from toppling over. This dual rail arrangement can use a cable set close to the outer rail for neatness, and allow the winch to be compactly mounted at the top of the rails. This design with no handrail has a few faults, - the pull of the cable will not be central to the centre of mass, so the seat will tend to try to distort unless securely mounted on the rails, so two sets of retained rollers must always be used to prevent toppling when the lift starts and stops. To prevent the toppling tendency, simply slow the speed of the winch, and ensure the winch cable runs parallel to the rails but pulling from the loads' centre of gravity, as this gives a far more balanced pull on the load.

The forces.

The bottom rail takes the simple compressive load of the weight of the lift and user.
Into the top end of this bottom rail is applied the winching force, but this is internal to the whole structure, plus the downward pull of gravity which is simply restrained by the screws into the stairs.

To make a more balanced pull, the upward pulling force is applied by the winch into the top ends of both rails and the winch cable is placed about half way between them, so the upward pull is applied directly into both rails fairly equally and thus self contained within the structure. By applying the lifting force equally between the two rails, distortion is minimised.
To prevent the weight of the whole system moving, the rails are prevented from sliding down the stairs by the dozen so strong wood screws though the bottom rail and also by the wall bolts on the upper rail.
In other words, two parallel bars, with a winch slotted in at the top end. Then fixed to the stairs and wall.

Warning: If making the winch separate from the lift assembly, then you will have to ensure the pull of the winch can be transferred to the lift. Assuming that any floorboards or weak walls or mountings will suffice is asking for trouble.

The other force of concern is the centre of gravity of the load.
As seen from the side, if you pulled from the bottom of the moving lift unit, it would want to topple over or jam.
If you pulled from the top, it would topple or jam.
If you pulled the moving seat and rider from the centre of gravity, then it would remain perfectly level with the rails and ride up the rails with minimum effort.
Therefore the actual point at which the cable attaches to the moving load will ideally be at the centre of gravity of the load, which will be somewhere about the position of the padded seat.
From this, the point of cable attachment to the moving load should also be the same distance at the top, for a neat and perfectly parallel cable run to prevent distortion or misalignment.

To repeat: The reason why it is preferable to have the cable pull the load from the centre of the rider mass, (somewhere about the base of the seat), is that the other options can cause distortion.
Consider pulling from the BOTTOM of the moving seat assembly, near the riders feet - the pull would want to pull the bottom up the stairs, but the rider mass would tend to stay where it is and so it would look as if it is tipping down the stairs.
If the pull was from the TOP of the seat assembly, then the cable will try to pull the top, but the bottom half would not want to be pulled up neatly.
Therefore by pulling centrally on the centre of mass of the 'rider and travelling seat assembly', the whole will be pulled up without undue distortion, for a neat, tidy pull and a much cleaner ride up the rails, especially when starting.

The lift is raised up the rails by a standard garage or car winch. Because cables can wear and break, the winch pull point also has a safety device in the sliding seat unit. If the cable breaks, then the seat must stop moving. See later.

The engineering needs.

Between the upper and lower rails is built a simple sliding frame, supported on ball bearings which place the load easily onto the lower rail. Onto this sliding frame is fitted a seat and armrest.
Two ball bearings are cheap but will suffice to take the heaviest load downwards. I used two ball bearings on each end, simply because they came to the same width as the lower rail and made manufacturing the bearing support brackets easier. Using just one bearing on each end will suffice, but will need some spacers to make up the width of the lower rail. The double sets also give a reserve safety margin should one fail. These were chosen as they are used in motorcycle wheels and therefore quite capable of this level of loading and easily available as scrap items from old wheels.

The winch cable which pulls the chair up the stairs must run onto the winch drum neatly.
This is an important engineering concern. If the cable run is such that it bunches up one end, then the lift movement will be jerky and potentially dangerous, so always ensure the cable will wind onto the drum neatly.
Therefore it is important to have at least a couple of feet between the winch and the seat cable anchor when at the top of the stairs, so the cable will wind itself neatly onto the drum and thus allow a smooth ride up and down the stairs.

The original design was to have a direct pull on the winch, but the room involved by the large mains winch unit was too intrusive to the stair users, so the winch was mounted on the floor and an intermediate pulley was placed to position the cable centrally over the winch drum for a very neat winding under load. This pulley was supplied with the winch.
It is important to have the cable pay-out and pay-in, to ensure a smooth lift action and to prolong cable life.

Seat design.

Ergonomically, the travelling seat has many hidden design considerations which must be addressed from the outset.

As the rider moves up past the steps, their feet may knock against the steps. going down with this problem is even worse. Therefore the user should be sitting slightly away from the stairs, with the feet over the outside of the steps. Good design will position the rider such that their feet will clear the steps, but not sit further out from the stairs than needed. This position is important, as at the top of the stairs, the user must be able to slide around over the upper step of the stairs with plenty of safe footing. This ensures the seat is mainly over the upper level and is an important safety aspect, as this is where secure footing is most important.

A long seat base will allow a stopped machine to be more easily stepped off, even in emergency. A very long seat can be used to carry extra items, such as a basket.

A rotating seat is not used on all stair lift designs, but should be considered. If such a rotating seat is complex, then make the basic stair lift first, then consider modifying later if a rotating seat is required. The following does not show a rotating seat, because the seat base is vinyl, allowing the user to twist on the seat for easier access.

The seat must be the right height for easy access and exit for the user. If built a little lower, then some extra padding or a few more sheets of plywood can adjust for individual users.
If the seat height is built too tall, then this is simply poor design.

The shape of the seat should also be designed for the most comfortable and safe seating. This is easily done by making a steel seat frame, with a larger plywood cover which can then be trimmed to the users most suitable movements and seating posture. A sheet of plywood can be changed many times until perfect for each user, which is another godsend of building your own.

If the user is insecure, possibly because of ill health, then a seat strap or second security bar, similar to a fairground ride can be added. Although a good, strong folding armrest and a non-slip seat covering is usually sufficient.

Most commercial designs take up a lot of room.
The design illustrated here is minimalist, and therefore has the whole seat folding up flat, which takes almost no room and is far safer for those who walk up and down the stairs.

It is common consent that the design of many modern items have gone 'way beyond their purpose', and like many cars, they have gradually got bigger, heavier, less efficient, less convenient and harder to park. (The Volkswagen Polo has allegedly more than doubled in weight since the original version, so needing a more powerful engine, making it drink more petrol.) I do not like this trend, be it in cars and many other areas. I prefer to keep design to the minimum needed, to only add extras when they are really needed.

Safety.
No clothing or body parts must be able to be trapped.
The design must not break.
If after many years, it should eventually break or wear, then the break or wear should be such that it fails in a safe manner.
The use of dual ball races allows one to remain working. The winch is understressed, and the rails are so basic as to be difficult to damage. The seat is a basic structure with a strong design. The folding seat is supported on a simple tube and slider which acts in a fail safe compressive mode. If the winch cable breaks, a safety device will stop movement.
The main concerns will be on wear of the components, especially on the cable and safety device as mentioned later.
During the design of such machines, immediate design standards and longer term reliability and safety must always be carefully considered.
Inherent safety in the seat design: Safety is not always specific devices, but a general approach to the design.
The seat must always be checked in all ways for potential problems: Simply being able to use it is not good enough - it must be safe in all possible scenarios. Expect kids, vandals and idiots to use the machine.
In this case, the simplicity of the rails makes for greater safety, but also the use of a simple frame which places the loads mainly in compression onto the rail and the lifting force applied from the main upright frame tube. The use of a shock cord also reduces forces on the frame and winch, and of course the user.
Whatever you do, try to make sure the design and components is such that it will fail more safely than any other possible method.

Where to put it: Making it fit.
This is a simple lift running on a strong base runner, plus a side rail to maintain vertical alignment. The bottom rail can be positioned wherever suitable on the stairs. The position out from the wall in this case is about 7 inches, but can vary an inch or two either way, depending upon the width of the stairs.
The chosen winch was 6.5 inches wide and fitted snugly in this gap, but if mounting your chosen winch design, then always check the clearances before a final decision. If not buying the winch yet, then make a cardboard box of the same size and draw in the shape on the sides, then work around this dummy box so it is integrated nicely into the design.

Manufacture hierarchy:
All good forms of engineering has a hierarchy of how they are designed.

The first item is the bottom rail set at an optimum distance from the wall.
The second item is a hand height guide rail. These rails must run perfectly parallel to each other.
The upper hand rail can be mounted relative to the bottom rail using a pair of identical wooden spacing rods to ensure perfect accuracy.
The third stage is to make the moving lift unit to fit these rails.
Finally a winch so the seat is pulled correctly.

In older houses, the stairs and the walls may not be conducive to a neat, parallel pair of rails, so some primary work may be needed. Use the rails to initially determine where packing or trimming of the stairs and walls may be needed to ensure the rails will be perfectly parallel.
In the example, the stairs were not a perfect parallel set of edges, and the wall was a little misshapen, being over 200 years old. For this reason, the hand rail was mounted just on two brackets at first, to align perfectly parallel with the bottom rail. Then the other brackets were tack welded in place after the other mounting holes were drilled. Then the whole upper rail welded fully.

The point to note is to make a good survey before starting, then you will know how to tackle potential problems: Dummy runs are ideal to prevent you looking like a dummy.

How to make it: Cheap or sophisticated.
Like many unemployed British science graduates, I prefer cheap, then make it sophisticated only as and when needed.
If the basic does not work, then you have lost little. The next version may be better, perhaps even a little sophisticated. And next year, you may wish to build the prefect stair lift, enthused by your newly learnt skills.
When you can do the basics and learnt form any mistakes, then you can start designing a more sophisticated design.
But upgrading is rarely the case, as most people without pretensions realise that a good working design is no better than any of the fancy, expensive stuff.
(Too many, expensive designs are called 'progress'. To real people, money must be kept to pay their council tax. It is the poor who end up paying for the rich to have fancy stair lifts, paid for by the obscenely high council taxes.)

Also a design a device that we all can afford.
When keeping costs low, the advantage of 'off the shelf' winches means the cost is low, hence cheap for this most expensive component. Spares replacement is possible but often much easier to replace the whole winch if anything wears.
Affordable can also mean ingenious, as the design shown here keeps the handrail concept and also takes far less room when folded up, being at least half the width of the nearest commercial design. My next design will be even narrower and may use a round, chrome hand rail.
This design can be removed and replaced easily within half an hour, leaving just the hand rail if wished. No damage can be seen other than a compression of the stair carpet where the lower rail was mounted. - You would have to look extremely hard to see that a stair lift had been fitted.
Because the winch unit is inserted into the top of the two rail tubes, it is self aligning and easily removed when not needed or for repair.

Safety mechanism.

WARNING: Some winches have a free unwind device, often activated by a button or lever to pay out the cable when used as a car winch. This must ALWAYS be locked from being used, preferably with strong glue or by removal.

Manufacture.

First check you can get the following.

The tubing is standard sizes and available world wide. 1 inch and 3/4 inch square tubing may be offered in metric sizes, but otherwise identical. Any suitable square tubing is stable. Angle bar and channel tends to be less accurate as it tends to bend easier. Square tubing is best as it is dimensionally stable, is very easy to cut and easier to weld the subsequent joins.
The electric winch. This could be a mains operated design, or a 12 volt design used for the front on off-road cars. Either can use a simple mains socket, but a dedicated electrical connection should be considered and on a separated fused line for reliability.
Do not buy the winch yet, as it can be bought AFTER the lift works well, after using a piece of rope to check the design. I checked I could buy a 240 volt mains winch from a popular bright red machine mart shop, which is common in most cities.
The winch came in a box marked with eight different languages, so replacement may well not be a problem, being made in vast numbers for a global market. I used the standard mounting brackets, so that any similar winch could be used.

The picture shows top left, a simple expanding wall bolt. Top right, a micro switch with lever. Centre, the new control switch, and bottom left, two winch cable clamps

The biggest problem I had was not in the stair lift, but in the control cable.
I tried many standard ways to allow the cable to extend and retract to the moving seat unit, but most were unacceptable, due to fouling on the cable, poor drag, or safety concerns.
I eventually ended up with a coiled wire over a nylon rope. It seems simple in hindsight, but I spent many hours trying with a cable which looped back on itself, looped cable running from curtain hangers and such like. Simplicity is often the best solution. It does not look too bad, works well and can be fitted high or low. Next time, the replacement will be in black cable so as to be less visible.

Switch.
This example does not use the control switch which came with the winch, as it was a bit too stiff for elderly people to use. I used a special switch which may take some time to find, but is not uncommon. The switch is a momentary, double throw, switch with centre off. That is to say, the left and right throws of the lever are momentary, that is to say, they must be held in place, as they will otherwise spring back to the centre position unless held. This will allow the user to push the switch to go up or down. If the user does not push the lever, then the winch will stop. This is a typical safety device common on most stair lifts.
Although these switches are not uncommon, they are not heavy duty. For that reason I chose a double pole version, which means that it is two switches in one, - to double the amount of current it could handle.
The third concern was its ability to handle 240 volts without problems.
The only design I could find from Maplin (FH07H for 150 pence) was rated at 2 amps at 250 volts, and this was too close for safety. - Luckily, the switch is a double pole, that is to say, there are two switch circuits in the switch body. By simply joining these together, you have a 4 amp switch, which will do nicely for my 240 volt, 500watt winch.
(Volts x amps = Watts. Therefore the switch would be more than able to handle the maximum winch power. In reality, the winch was only used at about one tenth the power, making the small switch very reliable.)
Buy two switches at the same time, so there is always a spare. Also buy two rubber waterproof covers which are also available if using this switch outdoors.
It is possible that you cannot find such a switch. In such cases, the simplest option is to use two switches, one for each direction, but it must be noted that it must be impossible to press both switches at the same time, otherwise the circuit will be damaged. Therefore it is possible to fit the two small push button switches with (option A) a dividing wall between them to prevent both being pressed at the same time by a single finger, or (option B) to fit a small butterfly piece of metal to pivot between them, so that only one button can be pressed at any time.
If you have some electrical experience, then you can (C) add a pair of relays which will isolate the other button when one is pressed, thus eliminating such problems, but at the cost of a little complexity. This small circuit could be fitted in a small plastic box under the seat.
If you wish to spend money, then you may (D) wish to purchase the control unit of a 700 watt 240 volt electric hand drill. This can be used with such a mains winch, as mine draws less than two amps, so the 700 watt drill version should be more than up to the challenge. Using such a control device will be fiddly to integrate into a seat arm, but can make a very neat and usable design and with the advantage of variable speed control.
Always buy a spare item at the same time.

The winch is as mentioned above and the rest is basic, commonly available stuff.

Getting the materials.
The metal suppliers are everywhere in the world and the only hassle is finding transport and using a hacksaw to get the long lengths into the van or on the roof rack.
If you can afford it, ask if they deliver. The tubing is supplied in 20 foot lengths but can be cut at the suppliers for a small fee. I usually take a 12 inch hacksaw, spare blades and tape measure to cut the tubes to the length needed on the stairs. If the single run for the stairs is too long for convenience, then consider making the rails in two sections for convenience, then weld or slide them together later.
The tubing may be supplied in protective grease, so take plenty of rags and old newspaper to protect your car.
Wherever possible, try to make the stair rails as single lengths. The bottom rail was the length of the stairs, plus two feet. The upper rail was similar.
Where possible, have the tubing delivered, so it can be used in a single run of tubing on the stairs. In such cases, it can be cleaned, then stored on the side of the stairs, and thus cut to length in situ. Tubing stored on the side of the stairs also prepares the household to get to recognise and prepare for the forthcoming new household device.

Tubing and welding supplies are from your local welding and tubing dealer. I used McArthur Group Limited. Plymouth. All the metal you could possibly need, at excellent prices.

In 2005, I have found the same winch unit which is now also available from Warehouse Direct at www.whdirect.co.uk for just 89 quid. This now makes a distinct possibility of making a stair lift for under 140 quid ! Such winches are probably mass produced by the hundreds of thousands in Italy or perhaps China for a global market, and as such are likely to be available for many decades. Perhaps the basic design will become even better and for less cost.

Setting out the design.

Walk up and down the stairs casually and naturally. Notice the position of your feet. This will tell you where a safe walking area is, and also where the lower rail can be safely positioned.
For a truly scientific assessment, dust the inside of a couple of steps with flour, then walk up and down naturally.
Place a comfortable chair beside the bottom step and check by siting in it, then mark the preferred seat height on the wall with a small, clear pencil mark.
Mark out the feet position so that they will clear the steps as they rise up the stairs.

Simply lay the bottom rail in position and test by walking up and down again until the rail run is acceptable. You will be looking for the best compromise between room for the feet and a reasonable distance off the wall for the bottom rail so that the maximum load will be on the bottom rail by being almost directly under the buttocks. Do not allow an unnecessarily large force which pulls the seat off the wall, caused by the bottom rail being too close to the wall.
The further from the wall the bottom rail the lighter the load on the upper rail.

REPEATED WARNING: Check the condition of the side wall, as not all walls are designed for side pulls and thus it is best to be safe. Only bad architects or 'designer' homes have lightweight walls beside stairs.
Look for thin walls or lath and plaster or even wattle and daub. Only when absolutely certain that the wall is strong enough should you continue. If the wall is not secure enough, then it may be possible to reinforce it, but only if the rest of the house structure is applicable.
If the walls do not allow bricks and cement, then consider using strong wooden beams secured to the presumably strong parts holding the stairs in place and up to the ceiling beams. These are best set into the wall, by paring back any weak wall areas, then plastering after the stair lift testing process is complete. If no wall is in place, then you may be able to position and secure a large wooden beam up and parallel to the stairs to make a secure hand rail and upper rail mounting.
If the wall is very frail or weak, then drill through to the other side and place large reinforcing steel or plywood sheets to take the load. Alternatively, build the bottom rail out from the wall far enough to take the full load centrally over the bottom rail, such that there is minimal load on the wall from the upper rail.
In most cases, stairs are mounted next to a main structural wall of the house.
Wall Test.
Take time to have a look at your wall: Drill a hole, fill it with a plastic plug to take a strong screw and fit a block of wood with a loop of webbing behind the block to make an impromptu handle, then try to pull the fixing off the wall.
If the house is very old, be it mansion, arched Georgian esplanade or merely a tenement, the walls may have been built from rubble, so there may well be some weak areas and some strong areas. To find the strong areas, make lots of little drill holes until the masonry drill finds something hard, such as a rock or small boulder.

If the wall is weak, then the whole weight of the rider load must be DIRECTLY over the bottom rail, so that little or no force is applied to the wall. The maximum load will be on the base of the riders buttocks, so sitting on a chair next to the stairs will allow you to measure where your maximum vertical load will be. Lift your feet to see where the actual load will be acting, then place the bottom rail directly under the buttocks.
When measuring, take note of the gap needed to be off the wall, especially clearance for the banister rail if very narrow stairs and of the backrest.

The hand rail will be about an inch and a half off the wall to allow for normal use and finger clearance. Then another inch for the width of the upper rail itself. If the backrest is thin and close to this rail then the centre of seat load (riders buttocks) will probably be about a foot (300 mm) off the wall in an ideal design. The bottom rail cannot be positioned this far off the wall, so about eight inches will suffice to prevent the lift wanting to fall outwards from the wall. The more the centre of load of the rider is over the bottom rail the then the less side load on the upper rail. The design point to note here is that the narrow stairs need the bottom rail to allow the ordinary stair users to have safe use of the stairs. It is the bottom rail that takes the main load, but if the bottom rail is not directly over the vertical load of the user, then the upper rail must resolve a small side load.

If the wall is not an option, then it may be possible to have two rails on the stairs, with the riders weight between them for stability. In such cases, the inner rail will be set slightly higher off the stairs to allow to a wrap around slider for extra security.

The stairs and their angle will be different for everyone, so the final design will be 'made to measure'.

Before committing to the work, It is often worth while to pin a piece of paper to the wall at the bottom of the stairs, and then sketch out the rough design, noting where any potential pitfalls may occur. A piece of plain wall paper lining paper is ideal. Mark the lower and upper rails, then the preferred seat height and its position partially over the first step. Then design a simple frame to support the seat between both rails and to support the backrest and arm rest.
Modify the design on paper until it is as good as possible.
Also sketch a side view to check it all works as expected.

Build the design.

Before fitting, always look down the length of the tube to check that it is perfectly straight. If bent, take time to carefully straighten the rail from the outset.
Cut the bottom of the rail to lie flush with the floor. Make a bottom end stop plate with a large screw hole and weld this in position.
Place one of the ball bearings at the bottom of the rail for alignment and to shape a simple bottoming end stop plate (often known as a bump stop) for the bearings. You may wish to include a block of rubber to reduce the shock of stopping, although it is not much of a problem. I fitted an old car valve spring as a bottom rail buffer which worked nicely as such a bump stop.

Position the bottom rail onto the stairs, then lightly screw the first bottom screw into position. Very accurately measure the distance of the rail off the wall and secure the other end screw for a rail parallel to the wall. Check for a perfectly straight run, then add a middle screw and check for distortion. Then fit all the screws on each of the steps. Fit a rag over the top end of the rail for safety.
Do not drill through the stairs on the very edges of the steps, but an inch in from their edges and deep into the risers for strength.
Mark first, then drill the holes, then countersink the holes for the screws and check the screws lie flush. If not quite flush, then the lift will still work, but the high spots on the screws must be filed or ground down later.
In the example, I did not have a large enough countersink bit, so I hammered a spare screw head into the metal until flush, then I fitted the rail to the stairs and dressed the screws flush with an angle grinder.

Do not screw the rail down firmly: Secure with just two screws, at about one third distance and gently tighten them. If the stairs are warped, then lay the rail in position and use the two most raised steps. I left the carpet in place, as it does not affect the engineering.
Now look down the rail to check it is perfectly straight.
In some cases it will be bent or distorted, so it is best to correct this with just two screws first, then to fit the other screws once the rail is perfectly straight. Some packing pieces under the screws are often needed to make it perfectly straight.
It is from this bottom rail that all other dimensions will literally run true. So make it perfectly straight.
Some packing pieces may be needed on steps which are a bit smaller than the others. I used slips of thin, tapered wood the same width as the rail, which were slid in until a fairly snug fit, then drilled the screw hole to secure the position and alignment.

If the rail will not screw securely into the stairs, then use long countersunk bolts right through the rail and through the wooden stairs, then use a block of wood under the stairs and secure it with a wide washer and nuts.

If you have delicate stairs, then weld some flat, extra support plates on the underside of the square tubular rail and screw these to the stairs. This will place the load vertically and if glass stairs, then these pads must be directly over the step supports.
With rubber shoes, walk up and down the rail and jump lightly and kick it to load the bottom rail and test alignment. Check again for straightness and any looseness, and adjust as needed.

Once the lower rail is perfectly straight and parallel to the side wall, then the upper rail can be made and positioned. The upper rail will probably be the same length as the lower rail, but if in doubt, leave it over-length.

Decide the ideal hand rail height, then make six or more wall brackets for the hand rail. The upper rail should be about an inch and a half off the wall, to enable it to act as a hand rail. Do not make a narrow gap, as if someone is clutching the rail and falls, then their hand can become trapped. The hand must always be able to slip safely off the rail if needed.
The ends of the upper rail will not be vertically above the ends of the lower rail, but slightly lower down the slope. The reason for this is that the backrest and seat will be partially either side above the leading edge of the first step, so the user can access the seat easily at both bottom and top of the stairs. Therefore, as the lowest ball bearing cannot be lower than the floor, the when the seat is at the top of the stairs, it will extend beyond the top stair.

Wall brackets can be found in many hardware centres using simple angle brackets. These must be trimmed so they will only just stick out of the wall by about an inch and three quarters. Any more and it will become obstructive to narrow design, and any less will allow fingers to be trapped. This gap will, indeed must, allow the slider guide to run on the upper and lower half of the hand rail tubing.
Decide the distance between the upper and lower rails. Simply decide your best hand rail height. For small people this will allow a smaller seat and for very tall people the proportions will also be proportional. It's called 'custom building'.

Weld just two of the brackets to the underside of the handrail, spaced about a third of the overall length apart. These will allow initial fitting of the upper rail.
Fit one bracket to the wall first, then measure accurately and fit the other to the wall. An alternative is to make up two identical simple V-grooved ended sticks of wood, by cutting them when they are clamped together. Then use these to position the handrail perfectly parallel to the lower rail.
Securely fit the handrail to the wall using three screws and wall plugs for each bracket, or use a good, solid expanding wall bolt. I prefer a single expanding wall bolt, as it allows the large washer holding the bracket to enable a degree of adjustably when fettling the rail alignment.
Once the upper rail is straight and parallel, more brackets can be fitted to align to any imperfections in the wall. If all brackets were fitted at once, there may be horizontal inaccuracies, as not all walls are perfectly flat vertically nor horizontally. By using just two brackets, the upper rail could be secured, allowing the other brackets to be fitted to the strongest parts of the wall, more accurately after initial alignment. Fitting the brackets to the wall, then tack welding onto the upper rail will ensure supreme accuracy, even on 300 year old non-brick walls with wavy plaster. Once tack welded, the upper rail can be removed and welded fully.

A hammer drill will allow drilling into brick walls.
In old houses with irregular building methods, then a few tries may be needed to get the most secure mounting positions.
The better mountings are expanding wall bolts. If the walls are crabby, then add some white pva glue into the hole before fitting the plastic wall insert or the expanding bolt. Some play in the holes in the mounting plates will allow the rail to line up smoothly and free of distortion. Some cardboard packing shims between the brackets and the wall may be needed for inaccurate walls to ensure a straight and parallel run.
Where the walls are not trusted, then it may be possible to use a though bolt to the other side of the wall and fit a sheet steel spreader plate.

Now test the rails by walking on them, or pulling on them as hard as you can.
Pull hard now ! - not later when it's far harder to repair any problems, Now is the time to ensure complete reliability that the rails are secure. Then check for alignment and correct any potential problems, especially parallelism, by using a V-grooved ended stick of wood. Look down the rails to ensure they are not warped or bent. If distorted, ALWAYS correct this NOW, as it will always make the rest of the engineering processes much easier.

WARNING: It vitally important that the brackets are welded to the lower inside corner of the hand rail so that a block can be fitted to the slider, to prevent the slider lifting off. therefore at least half of the bottom of the handrail must be free of obstructions, so that the subsequent lug on the slider will prevent vertical movement off the rails.

Welding.
A fuller monograph on welding is on this website. A quick guide: Make sure you are wearing dark welding mask and gloves. Mount the workpiece securely and clamp it to the earth clamp. Strike the welding rod as if a match to strike and arc. The arc is then used to melt the rod and workpiece to fuse the molten metal into one piece of steel.
Striking your first usable arc may take a few hours, or may come naturally, as it is more of an art than a basic skill. Therefore practice on old pieces of steel until proficient at making a deeply penetrated weld between two pieces of steel with a smooth surface. Cut the weld in half, or hammer it apart to check the quality of the weld.
Most people will need at least a week to become proficient at arc welding.

The upper rail brackets need welding and so does the frame. Welding is not easy at first, but most people eventually master the skills to some degree. The welder will take some time to master.
MIG (metal inert gas) is easier, but arc is far cheaper and is the classic form of welding.
A 120 amp or larger arc welder, with a selection of welding rods up to the standard 3.2mm dia. Or a 120 amp MIG welder will suffice. The picture shows my unreliable MIG left and my favourite, reliable, yet cheap stick welder right.
If in doubt, then tack weld the design and get an expert to do it for you. Once the design is tack welded together, it should take less than an hour to weld fully. Ask around for anyone who can do welding for free for the unemployed, as there are many such people like me who are similarly unemployed or retired.

Not everyone has access to welding skills.
The upper rail could be screwed or bolted to the brackets, using countersunk bolts on the underside, but will need very neat engineering. If you have excellent wood working skills, then it is possible to make a wooden sliding frame, but this will need strong wood and excellent wood working design and skills. In many cases, it could be a variation of a wooden seat frame, braced with large triangular fillets of plywood to take the pull of the winch.

Building the rider seat unit.

The bearings are spaced either side of the vertical centre line of the intended seat, to balance the load of the rider. It will be noticed that due to the lowest position of the rail, where it touches the floor, the bottom ball bearing will be supporting most of the vertical load, with the upper ball bearing used partially as a steadying component. (If you have just three ball bearings, then use two on the lower position to take the load and increase long term reliability.)

The main upright tube of the seat unit will be long enough to reach from the bottom ball bearing area, to beyond the upper handrail and up to the backrest. This will be the main vertical tube of the seat structure.

A secondary vertical tube from beside the upper ball race will then make a basic triangular frame to slide up and down these rails.

As all designers know, the inherent strength of the triangle greatly reduces distortion and misalignment when being pulled. The strength must be at the bottom to take the load, then onto this man triangle, a seat support part way up, then the upper part of the frame as a guide rail holder.
Because the bottom rail is at about 45 degrees, the main upright is almost vertical on such a design. The lower part of the triangle is the tubing supporting the bearings. The third tube is from the upper ball bearing to the upper end of the main upright. This makes a triangle which can keep all the relevant parts together in a strong but light structure.
I have made the upper point of the triangle close to the upper rail, as the area above the rail is merely for a backrest and is not structurally important.

Take time to look at the basic design and get a feel of how this is to be pulled up the rails. Understand that the vertical rigidity of the triangle helps to prevent distortion and keeps the design simple, also where the weight is to be loaded and where the best cable puling point will be.

The picture opposite shows the finished basic frame with folding seat and stay tube. The (vanishing point) rail lines are marked.
The (red) base triangle can be seen. (A small lug was left at bottom right for optional footrests if needed.)
Above this the (green) backrest support and upper rail slider.
The green protruding lug at top right is the armrest pivot.
The central vertical bar is the sliding support stay arm for the (blue) seat.
The (blue) seat is made from three horizontal tubes and is hinged on the lower horizontal tube.
The dark grey vertical tube is the tubular sliding seat stay.

This is unlike most stair lifts as it lies very flat against the wall.

At present the builder will have only the triangular frame, positioned by the lower ball bearings on the lower rail and resting against the upper rail.
Because the handrail is only there to prevent the slider unit from falling away from the wall, this needs only be a simple sliding sleeve. I used a piece of shallow U bar from a disused TV stand. Alternatively, cutting down a piece of the one inch tubing lengthways, then welding together will give an upper slider which will maintain its position over the upper three quarters of the hand rail, preventing the slider unit from falling away from the wall.
The U tube is placed over the handrail and a couple of millimetres gap used to allow free movement. I used a piece of paper to space the slider over the upper rail tubing, to give a neat sliding fit.

A dummy piece of upper handrail tubing can be used to assemble the upper slider and test for a neat sliding fit. If you are having heavy users, then add a thin film of HDPE between the slider and the handrail.
(It is possible to fit ball races to retain the upper hand rail alignment, but as this is lightly loaded, then a more simple sliding bearing can be used: I used an old oil container.)

HDPE is high density polyethylene: The same plastic used in prosthetic hip replacement joints which offers excellent properties. Look for the HDPE sign on old plastic oil containers as used in car oils and plastic milk bottles. Cutting a sheet and folding it over the rail, then making the slider to fit, will allow the plastic to be heated and thus form to its new shape along the back side of the upper guide.
Clean the metal, add a few holes for retaining the partially molten plastic, then heat it until it permanently deforms to the desired shape, to turn an old plastic oil container into a full length HDPE bearing surface inside the upper slider. An alternative to HDPE for a bearing surface is to use ski candles, which are similar and low friction in nature. Heat the metal first and light he ski candle, to drip the molten plastic into position.

Welding the slider in place should not cause problems as the welds will not be too hot to badly melt the plastic, but only if using short welds at long intervals to allow cooling. If the plastic melts, then an old oil container can supply plenty more replacement pieces. Always polish the upper rail and add a thin layer of grease or candle wax, so the machine can be easily removed prior to final assembly.
Warning: NEVER cool the welds with water, as this causes cracks and potential early failure.
If holes are drilled in to the guide, then heating will allow the HDPE to be gently pressed as it gets partially melted, to prevent it sliding inside the metal. In most cases, this should not be needed.
In cases of a heavy user, then a ball race may be integrated into the back of the slider instead of a plastic film, but if properly designed, then the forces on the upper slider should be minimal.
I took my time and polished the upper rail with fine wet-and-dry abrasive paper, followed by a kitchen scourer pad, then used some candle wax on the upper rail to ensure slip free, but sliding surface.

Place the triangle frame on its rails, push down with your feet to firmly secure the triangle on the rails, then tack weld the slider guide to the back of the triangular frame. Check it all sides smoothly along the whole length of the rails.

Now carefully inspect how the basic frame on the ball bearing base and the upper slider moves on the rails, to check you have the dimensions aligned accurately all the way up the stairs.
At this stage of the build, the triangular frame also becomes a specialist checking tool: Check the running and sliding, noting any imperfections which should be cured at this stage. If all is well, then fully weld the basic frame.
The slider unit is a basic triangular design as this prevents distortion when seen from the front, (but allows a little twisting when looking from the side, should the rails be imperfectly aligned, or the walls warp with time).

Take plenty of time at this stage, as the rest all depends upon this assembly working well.
In some cases, the run may become tight, as the pressure applied to the triangle causes the upper slider to rub hard on the upper rail. In such cases, the upper rail may be gently tapped or persuaded slightly to ensure the slider moves freely. Do not allow to much distortion to accumulate in the design, as the rails, if perfectly straight, should allow the slider to move very freely. In most cases, just a little light filing to smooth out any dents, protruding screws or welds in the rails should be all that's needed.

Prior to fitting the seat, the rest of the backrest can be made. In the example, this is just an extension of the rest of the triangular frame made from the small square tubing. With this extra tubing above the upper rail then the other end of the upper slider can be welded to it to create a fully strong slider.

NOTE: One other main components must be added to the frame later, - a block to prevent the slider from lifting off the rails, this takes the form of a welded or bolted pair of lungs under the upper ail, to prevent removal should the cable break or the rider get out of balance. The securing lugs will be added later, to allow the slider to be easily removed for further work and refinement prior to final construction.

Once the basic frame is made and sliding well, most of the main work is done.

Fitting the seat.
The seat height can now be finally decided and mounted according to the users needs. Check the seating carefully, because the user will have problems with their feet knocking against the steps and perhaps knees knocking against the banister if very narrow stairs. Therefore the user will probably be sitting facing slightly away from the stairs, yet with the seat positioned such that they can exit safely at the top, perhaps by sliding around on the seat to get their feet onto the top step.
Should the lift stop partway, the user must also exit easily.

Because the user is sitting at various angles when getting on and off, the front edge of the seat is often slightly curved to aid ease of movement, but deep enough in the middle to maintain secure seating. Do not have any sharp corners to the seat.

In the example, the seat is simply folded up on a basic hinge of any reasonably strong design. At the front, a vertical support from a small tube and sliding bar design allows the seat to fold away easily, which supports the seat securely when in the down position.
In the example, the seat is maintained in the down position and takes the weight of the user by using a simple tube and inner slider leg. The small tubing and bar can be found from old domestic items such as an old ironing board leg, kiddies push bike frame tubing or whatever is available and strong enough.
The hinge should be positioned such that the seat folds flush with the frame, but also takes into account the room for the plywood seat base, padding and covering. Therefore the hinge will be set lightly out from the frame.

Balance test: With the basic seat built and welded to the frame, place the frame on the floor, away from the rails, to check the way it is loaded: Sit on the seat and balance to see where the vertical load is actually applied. the seat should tend to fall in towards the upper bearing, which denotes that it will be stable when on the rails.
Also check the backwards force needed to keep upright, to measure the sideways load which the hand rail must maintain.
Alternatively mount the frame on the bottom rail but OFF the upper rail, then sit on the seat to see what force is needed to push the seat upright against the upper rail. In most cases this sideways load away from the wall will be minimal, often just a few pounds force. Now apply twice this sideways load to the handrail to check the upper rail safety.

The metal seat frame should be slightly smaller than needed and a larger plywood cover used, then trimmed to the best shape for the user. Plywood allows the seat shape to be modified for personal preference.
Once the seat is the best shape then the plastic, leather or cloth covering can be applied over a foam pad and stapled into the underside of the wood, or use glue and lots of special seat tacks or drawing pins. A few small, countersunk self tapping machine screws can then screw the upper surface of the seat base directly into the seat frame.
Do not have the seat base tight up against the back of the frame, as folding it up will cause the seat to be pushed out at the base, so at least remove any rear padding and always check the way the seat folds up neatly before permanently applying the padding and covering.
A little foam under the vinyl covering helps comfort. If no vinyl covering is available then you can use dyed denim from old trousers, or even strong curtain material to match the rest of the hallway.
The seat covering should be such that is resists slipping, with a textile covering rather than a smooth vinyl covering. If using vinyl, perhaps for easy cleaning, then to reduce slipping, try not to use any smooth finish vinyl. I used artificial leather effect vinyl seat covering, commonly available in many colours, from most haberdashery stores or fabric remnant stores.

The armrest is mounted on a simple pivot onto the long upright triangular frame tubing. The armrest must also be narrow when folded. To retain a strong sideways force to prevent people falling off, then the arm rest mounts must be very strong and yet allow it to fold safely into position when in the horizontal plane.
Once the armrest is fitted, it must be tested with a high sideways force to the armrest as if accidentally falling down the stairs. In the design shown, the upper pivot of the armrest sits on a 10mm bolt, and the bottom part of the armrest sits in a rectangular socket cut from the rail tubing so that it can resist any sideways movement.
To retain itself in the upright position when not in use, make a friction pivot on the armrest, so it can be folded upright and out of the way. If a threaded spindle, or a pin retention used, then the metal washers could include a small rubber washer which can be compressed to maintain a light amount of friction.

You should now have all the main components in place, other than the lifting mechanism.

The above text may seem difficult to understand, so here is a quick, simple overview.

Summary.
Buy some thick wall One Inch square tubing, and keep it straight.
Lay along the stairs and allow a couple of extra feet extending beyond the upper step.
Carefully check all is truly straight and parallel, weld on a bottom bump stop, then screw the bottom rail to the stairs.
Make up two identical spacer planks and mount the upper rail parallel to the bottom rail, set about an inch and a half off the wall to also act as a hand rail.
Make brackets to secure the top rail to the wall.
Make the upper slider which is able to slide easily without obstructions. Make sure the securing brackets do not obstruct the slider.
Build a bottom part of the triangular slider frame with ball races and with guides either side of the bottom rail to allow it to slide on ball races on the bottom rail.
Build up a triangular frame from the bottom slider, to just above the upper rail.
Make up a slider for the upper rail and make sure it all slides up and down the whole length of the rails neatly and smoothly.
When sliding well, make up the rest of the backrest, then weld the other end of the slider to the frame.
Check the seat height, then mount a simple folding seat. Make a simple sliding tube support for the seat when in the down position.
Make up a plywood seat base, trim to personal preference, test with a heavy load, then cover in foam and cloth or vinyl.

Testing 1.

Now is the time to assess the way the winch will pull and the actual loadings as checked in the real world, rather than by earlier calculation.
In the picture opposite, note the upper rail, lower rail, the winch cable leading to the hook and the shock cord, and below this the nylon cord with looped control cable.

Checking the basic lift.
Using strong rope, a reasonably strong person can pull a seated person up the basic design, because the effective force needed up a slope is only half their weight.
This will allow the initial checks to ensure there are no unforeseen flaws.
Do not pull the user up the stairs too far, but just enough to check the loading and action.
If you have no user, then a couple of sacks of potatoes or whatever you have available can suffice if adjusted to make a suitable test load. I used my mechanics tool box, which weighed eight stones. I could then safely test the machine along the full length of the design.

By placing the rope around various parts of the loaded slider, the lowest friction position for the cable can now be checked. This test will theoretically find the best pull from the centre of the load, and thus impart the minimum distortion to the slider frame.
Be warned: Pulling from the bottom will tend to make the upper half drag behind and cause distortion in the frame. Likewise pulling from too high on the frame will also cause problems.
You may note that the slider precariously comes off the top of the rails, and later a safety lug will be have to be fitted to prevent the slider from lifting off the rails, but at this time, having the slider lift off in any poorly designed, unwanted manner is helping you to discover the dangerous aspects of the possible poor design and finding the best cable attachment position.
Having the slider seat unit easily removed by sliding off the top end is much easier for modifications, and it also highlights any unwanted offsetting forces when pulling a full load.
Try a few fast and jerky pulls to check for any unwanted or offsetting forces.
When the slider can be pulled smoothly, truly parallel and without bending, then all is well with the design, and the force from pulling on the cable is getting close to perfection.

After various tests with a full load, the ideal pull point will be determined to a reasonable approximation. This can now be checked by measuring the force applied to lift the load up the rails.
I placed a long length of strong cord to various parts of the loaded slider to check for the best pull point and to check the action of the slider on the rails.
I sat on the top step, holding bathroom scales, with the top of the rope around the top of the bathroom scales and then pulled on the bottom of the scales to measure the pull load on the loaded slider. It was a tad awkward, but an eminently simple way to test the actual working load needed for the design.
Not surprisingly, the best pull was from the centre of the load, about central with the seat base, as seen from the side, and the pull of the cord was of course, parallel to the rails.
An old washing line or a few lengths of string will probably suffice for testing. By making a large loop in the end of the cord, and placing the cord around a bathroom scale, then pulling parallel to the rails, the builder can properly check the actual winch loadings needed.

In the example shown, an eight stone (50 kg) user was pulled up using a 30 kg pull. This equates to an actual lifting force up the 45 degreee slope of f 25 kg, plus an extra 5kg for acceleration and frictional losses. Likewise, static load was just under 25 kg, showing a 5kg amount of friction in the movment. The friction was gradually reduced by fettling the mechanism to reduce distortion and friction as the rails and runners were smoothed and fettled with use.

Structural strength.
With the basic design in place, fully test by pulling and trying to overload the design and mountings. Get two people to stand on the seat when it's at the bottom of the rails to test the static structure. Then place two people on the seat when it is held by the rope half way up the stairs.
Push against the armrest, to check it will prevent anyone from falling down the stairs.
Finally check for any cracks or distortion in your workmanship.

Possible problems.
Lack of parallelism.
This will lead to tight spots or loose spots on the run and must be avoided as much as possible. Always check the rails first, as these are the primary alignment reference points. A maximum of 5mm play in the upper handrail guide can be permitted, if the upper guide allows this amount of play and if the upper rail is securely fitted, so that the seat unit cannot come off the rail under any circumstances.
Where necessary, use the more shims under the bottom rail to ensure it is perfectly straight under load, and then check the hand rail to match a perfectly straight bottom rail. Where the load distorts the bottom rail, add some packing pieces to keep it straight under load.
In some cases, a little bending can happen after welding, therefore the rails and seat frame must be checked for straightness. Straighten carefully and gently, as bending too far can cause more problems. Always remove the frame from the rails prior to bending them straight, so that the rails remain perfect.

Cable pull. By positioning the cable pull point at the centre of the load, minimal distortion will occur.

Fouling of components.
The use of sliding the lift using a rope allows the system to be tested for anything which can cause problems. The main aspect is making sure the whole system will work freely and nothing fouls or rubs against anything else. Also the winch will need some space, so the lift area will need to be carefully checked for clearances.

Listen to the lift as it runs up and down, especially the runners and guides. There will be some minor creaks and groans as this is taking a heavy test load. Look for unusual or high friction patterns on the sliding components.
Where the upper rail slides without a bearing surface, the two bare metals will cause abrasion which can lead to rough metal surfacing and pitting. Carefully check with your fingers for metal abrasion. The solution to easing the abrasion areas is to use some metal polish to allow the two surfaces to rub more smoothly until after testing, then a light waxy surface on the back of the rail. Old candle wax is superb as it's not sticky. If abrasion persists, then a small roller can be incorporated to reduce abrasion, or HDPE rubbing strip used as a low friction barrier inside the guide. In the example, the upper guide with metal to metals runners caused minor abrasion on the hand rail so the upper guide was heated and pieces of HDPE melted into the surface to create a low friction surface film on the slider. The hand rail was also carefully polished to greatly reduce abrasion and friction. Then a wax candle was rubbed into the handrail friction areas to reduce the abrasion without causing an oily or slippery surface.

At this point, the basic stair lift is created, albeit without a winch mechanism.

Safety mechanism.

The most serious problem to be considered is if the winch cable breaks, or the winch fails and cannot restrain the cable.

Therefore should the winch system fail, some device must be in reserve as a fail-safe device which must always prevent downward movement.

The safety device used here is a simple leg which drops down onto the steps to block downward movement.
The leg is naturally in the down position caused by gravity and on a very loose pivot. This safety leg is raised into the up position ONLY while the winch cable is connected.
If the winch cable breaks, the leg MUST drop and the lift will only be permited to fall as far as the next step.
Therefore the link retaining this leg in the up position is a very weak link, so it can fail easily.

The leg itself is very strong and placed to act in a compressive manner onto the next lower stair step when the weak link is broken.
The leg also has a sharp digging bottom edge, so that it will tend to dig into the stairs rather than slide off.

The leg can be made from thick metal as this extra weight will help the action, aided by gravity. Gravity will always be ready to act: Other forms of deployment may not work when needed.
The leg is held in place by a weak, very small piece of knicker elastic which keeps the safety leg up just enough when in use. Cotton thread can also be used, but thin knicker elastic allows a little play in the design and thus reduces false breaks which an unforgiving cotton thread may cause.
An alternative is a fine piece of cord, or in this case a loosely and weakly fitted piece of wire. This will allow the connection to easily fail if this weak link is pulled away from the seat by a broken winch cable. If the winch cable fails further up from the main seat connection, the connection to the shock loop will still drop, and thus allow the leg to drop into its safety position.

WARNING: When the safety leg blocks the movement downwards, there will be an upward reaction. To prevent problems of the seat lifting off the rails due to the safety leg reaction, there MUST be a safety bar under the lower run of the handrail to prevent the slider coming off the rails. It is vitally important to check the safety device unit does not cause the lift to come off the rails. This safety bar will be added before final assembly, so it will still be easy to check the basic action of the sliding seat unit and the need to remove the seat many more times before it is perfect.

Under no circumstances must the chair come off the rails.

In the above example with the simple lever safety device, the lift is but such that it CANNOT be removed from the rails in any working nor failed position.
The final form of the slider unit had to be slid off the end of the top of the rails, as it must not be able to be removed any other way for safety reasons. In this design, the final seat unit can only be removed by sliding off the upper end of the rails.
If the cable fails, then the safety lever would stop the lift with a heavy load and press against the steps, and also press up against the upper rail with a little force, but the seat must not be able to leave the rails under any circumstances.

The reason for the light spring load on the safety leg is when having to lower the lift with an unloaded unit. In such cases, a little spring load is needed to keep it up, out of the way.

Whatever happens, if the winch cable becomes disconnected or slack, then the leg must always drop and the seat unit must remain on the rails.

The design shown here is very basic and works reasonably well, but further sophistication could be done with a different safety device which could use a spring loaded metal wedge which can jam the bottom slider on the lower rail. Hard wood wedges can also be use to take advantage of their higher friction coefficient. Likewise a sprung lobster claw or offset rollers which servo grabs the bottom rail can also be used, but such designs involve more complex engineering and hardened jaws. The simplest is the drop leg to prevent moving beyond the next lower step. Simple is invariably the most reliable.

The cable mounting point.
Before investing in a winch unit, the cable mounting on the seat slider should be made first.

The mounting point of the winch lifting cable fits to the seat unit will be about half way between the upper and lower rails, near as possible to the centre of gravity of the seat and rider. The lifting force from the cable must be such that it causes little distortion as the seat is pulled up the rails. If the pull was from the top of the seat, then the chair would want to dig into the upper rollers. If the lift force was from close to the bottom rail, the initial acceleration would want to tip the top of the seat backwards.

Because this example is a rather high speed stairlift, using a mains powered winch, the 'pull point' must be well balanced with the user load. On slow lifts, the pull point is not so important, but perfection should always preferred.
Some slow (commercial) stair lifts get away with atrocious pull points.
The best cable mounting point is where all the mass is centred on the seat, so the force of the lift can be even and with minimum misalignment on the rails during acceleration. The ideal bottom cable mount would be at the seat, but just below the seat works well enough and is the position chosen on the above design.

It may be noticed on the example that a lower mounting point was also added, but this proved unacceptable although it would have made a neater winch system. The more central pulling point was used to ensure the physics of the mass during acceleration was controlled properly. (Perhaps my B.Sc and Mech Eng Tech weren't totally wasted.)

To ensure that a very safe cable mount is integrated into the triangular seat frame, a large solid bar was made into a loop and welded to offer a suitable mounting point on the seat triangle. The free end of the bar was kept long and ended in another loop. By mounting the large bar of the winch cable mounting point around the back of the main upright, this will impart a safe, compressive load through the structure (pulls from around the main upright tube) and thus safer should any welds break.
The cable mounting will become part of a shock loop system as described later, to allow for a gradual take up of the load and reduce shocks to the winch unit. At this stage, the basic part of the shock loop system allowed direct connection to the winch cable for initial testing.
(There are other good yet simple shock loop systems. An example is used in the excellent Dyson vacuum cleaner cable.)

In the picture opposite, note the narrow size of the winch tucked behind the lower rail and also the looped control cable running on the stretched nylon parracord.
Also note the badly wound cable on the drum. During tests, the cable was carefully guided onto the drum by hand, such that it laid neatly wound. Neat wrapping around the drum from good pulley placement reduced a lot of jerkiness and lowered noise in the system. Allowing a cable to wind badly onto the drum causes jerkiness and greater wear on the cable. so always keep an eye on this during testing and allow the cable to wind itself neatly.
To help the cable wind itself neatly, I coated the cable with candle wax, so it would slide more easily into the adjacent coil on the drum.

This main attachment bar from the cable to the seat base is commonly available, as it is a solid steel, lower seat belt mounting bar from four seat, two door cars, available for a few quid from any scrap yard. Standard solid steel bar is also available almost everywhere.
There are many ways to clamp a winch cable into position to the seat slider. The best is always to use the standard components as supplied, as they will be tested to a proper safety level.
But if like me, you do not want the often cumbersome garage hook bits as supplied, then the cable must be threaded using the proper sleeve eye to prevent abrasion to the cable over time. This is then clamped using two sets of U bolts. Tying knots or fancy clamps is NOT recommended unless you are a professional wire strop splicer, which is probably a lost art I last studied over twenty years ago.

The winch cable is pulled slightly back from the actual mounting point on the seat, held back by a bungee to give a degree of shock absorption for a smoother start. This little bit of movement also can allow the safety device link to act and pull up the safety leg before moving. The winch cable has a direct connection to the safety device, which must allow the safety device to be activated if the cable fails. More on this later.

On the design illustrated, the cable mount to the seat is long and allows the cable hook to slide a little which can be incorporated with a spring (the bungee shock cord) to pull the cable back onto the mounting. - So when the lift reaches bottom, and the switch is still pressed for a second, the cable can remain taught, but without the load. When the winch begins to lift the user, the shock cord also allows a small amount of gradual acceleration.

TIP: Do not make the sliding seat unit too light, as the winch cable will need some load to unwind it easily when descending without a user. If you have poor build quality, with undue friction or when design problems arise, then simply add some weights to the slider unit to help it unravel as it descends without a load. If using a small winch then the winch could be mounted into the lift itself. Alternatively, if a 12 volt system, then perhaps the battery and the winch can be mounted in the lift unit.

After the basic engineering is done, there will be the basic slider running on two parallel rails. With the winch in position, the cable can be mounted to the slider and tested under a full load. If all works reasonably well, then make some more runs to fully check for distortion and low friction.

If it does not slide too easily under load, then take time to fettle the way it works. This is best done buy sliding it up and down by hand or a piece of rope so you can sense for any tight areas with a full load and a light load.

Once the loaded slider slides nicely, then the safety device can be adjusted to act correctly. The clamp which draws the leg into the moving position can be adjusted, so that when the cable is relaxed, the leg will drop down under the action of a spring.
The safety mechanism can be tested by pulling the seat unit part way up the stairs by hand, then suddenly releasing the cable to simulate a break. Use a pair of gloves on the winch cable to prevent injury.

Once the seat slides freely and the safety device is working perfectly, then the shock unit can be made.

The shock spring is difficult to get right, as one spring does not fit all rider weights. So a metal loop and bungee cord can be used to adjust the action so it will only raise with the minimum unloaded load on the design. This will need a light spring load, but simple adjustment is easily done with bungee cord.

At this point in the build, the final position of the winch drum or intermediate roller is decided to run the cable parallel to the rails. Now, when confident in the lift, then the investment in a winch can be made once the lesser cost of the wiring is finalised.

Electrics.

The electrical cable which runs to the chair could run in a simple plastic channel, or with a simple strip of plywood channel nailed onto the skirting board so the cable can run safely and cleanly as the lift is used. Unfortunately, this did not work too well in practice, as the upper cable run would sag.
Alternatively for simplicity, the cable can be coiled around a nylon cord, such that it pays out loosely as the lift descends, but neatly loops into a bunch near the seat as the lift rises. This is commonly used in industrial overhead crane applications, with a version of curtain hangers. I tried curtain hangers, but these did not help either.

In reality, the run of the control cable from the switch in the armrest up to the motor was toilsome to test in various forms, with most designs fouling in some position or other, or simply looking awful.

I ended up with a looped coil of wire over a nylon cord. The cord can be stretched just above the steps, as in the example, or mounted below the handrail or anywhere where it will not be trapped by the stairlift during its travels. This was chosen to run a few inches clear of the steps, to allow easier cleaning of the stair carpet.

The coil of wire for the control cable was made using 6 amp 240 volt domestic flex cable and this was tightly coiled around a broom handle, taped at both ends, then gently heated for half an hour in front of a domestic fire. I did not want 13 amp flex, as this would be too inflexible and heavier. Because I wanted a safety margin over the intended 2 amp use, a lighter flex was unacceptable. A 6 amp cable was just right for the calculated 2 amp system.
If the 6 amp cable is too thick for your use, then simply use two parallel runs of 2 amp cable.

When cooled, the three-core wire tended to unwind a little, but otherwise was well behaved. This was then slid onto the nylon cord. The nylon of the cord would ensure that no electrical injury would happen should the outer sheath of the mains wire become worn after many years of sliding up and down the nylon cord, should lack of maintenance caused by a bare wire. Regular inspection will be needed.
NEVER coil the wire around the winch cable.
The position of the cable on the cord was then tested to see how it behaves in the various positions of the lift, and then the upper mounting point decided accordingly.
To prevent unwanted drag on the control wire from the nylon cord to the seat, a sliding wooden block was added on the lower end of the nylon cord, which is tied to the seat to prevent unnecessary drag on the coiled control wire where it connects to the seat. A strain relief was also added at both ends of the electrical wire, so the coil of wire is dragged up the cord evenly and without undue stress on both ends of the three-core wire.

This design uses a three core cable. One wire is a simple mains feed into the switch and the other two wires are the power to the up and to the down connections on the motor.
Occasionally, the builder may need a four core or more cable for their control system. This may mean a pair of two core electrical cables, which can be easily coiled together. Vinyl glue is available although simple electrical tape may also suffice to ensure neatness.
If running the cable in a tube or laid flat on the stairs, ensure they will indeed lie flat. If using two cables, then they can be glued together with some vinyl glue to make a wider, flatter cable. To glue two cables together, simply lie the long lengths side by side on a flat floor, then glue and place blocks of wood or metal tubing to push them together. This should give a figure of eight section to the cable which will lie flat in the channel when the lift goes up and down. If this glue technique does not appeal, or the glue is unavailable or too weak, then simply use strong thread in a figure of eight over the cables to criss cross the cables to bind then together. A figure of eight pattern will keep them evenly spaced together.

The example of a coiled control cable was given a standard 3 pin domestic flex connector for easy replacement every five or ten years or so of constant use. Because this stair lift is needed to be easily disassembled, this connection to the chair unit also allows very easy disassembly of the basic components. This could also be positioned to unplug safely should the cable become snagged. (Safety can often become inherent in the design, if used with just a little extra thought.)

When the final position of the cable is decided, the nylon cord to hold the coiled electrical cable was stretched parallel to the rails. It was tied at one end, with a spring from an old bedstead used to maintain tension at the other end of the nylon cord. I used as dual nylon cord for greater safety, as it's cheap and also helps maintain long term reliability by rubbing more lightly and on two areas of the vinyl cable sheath of the coiled cable to reduce the wear. plastic rather than metal will help insulation and prevent shock should the wire sheath abrade faster than expected.

Switches.
The choices of switches and their placement will depend upon the user.
For some, a relay control system using just a low voltage control wire can be used, allowing a much lighter sliding cable. The use of relays adds complexity but also offers a little more safety if designed well.

The switch chosen was for greatest simplicity.
In some cases, such a switch is not available and so a standard double throw switch may be used, plus a separate 'operate' push button switch - one switch to choose direction and one to move, as this reduces confusion and improves safety.

The simple control switch can be mounted into the armrest. This must require some careful electrical connections in a manner which ensures the wiring is always isolated from the user.
Making a wooden armrest will allow the control switch or switches to be carved into the wood in reasonably sophisticated and stylish manner, while also offering electrical insulation.
If separate switches for up and down and for speed control, then these should be mounted clearly and in a manner which is natural for the direction. Use of one switch MUST preclude the use of the other switch.

The most basic control is just an up and down switch. (Single pole, double throw, momentary. (Double pole was used for greater current capacity))

The switch shown is simply mounted into the carved armrest. The controls are easy: just push the switch the way you wish to move. The original switch which came with the winch was far too heavy for an elderly person to use.

Safety: All switches must be free from being knocked and therefore must be protected by the shape and form of the mounting area. This can become a sculpting part of the project and allows a large degree of natural flair.
In the example case, just a simple curved hollow was used at the end of the armrest. In use, the way the switch was on top of the armrest caused it to be pressed while the user was entering or exiting the seat. Therefore a protective bar was then added to prevent it being activated in this manner. Later versions may have the switch exiting from the end of the armrest or fully flush with the armrest, so that placing the hand on any part of the armrest will not unwittingly activate the lift.

As the winch in this example is rated at 500 watts and 240 volts, then this will also be able to be switched with minimal control complexity as fitted on the original garage lift specification.

Possible alternative switches are available on electric drills and offer variable speed plus bi-directional control in a simple, compact trigger unit. As such switches are available for the more expensive electric drills as spares, then the control system can be surprisingly cheap yet sophisticated. These switch options are also small, compact and easily replaceable.
If you have a problem with the lift being too fast, then consider such a progressive switch as a possible option. They often have a speed control consisting of a dial which prevents the trigger being pressed in too far.

(I am surprised that firms like Black and Decker do not make DIY home stair lift kits.)

The final choice in the example was a simple centre-off double throw momentary switch.

As the whole design is modular, the wiring to the sliding seat unit could be disconnected using a three pin plug behind the back of the seat unit.

Fitting the winch.

If the winch has a freewheel drive which allows the cable to be payed out freely, then this must be locked so it cannot be used, preferably using a dab of strong epoxy glue or removal of the operating device.

Near the winch should be a mains socket for the motor or the battery charger, which will include an integral fuse. An accessible mains switch can also be included if desired, should the person wish to switch off such electrics when going to bed.

Once the winch is available for final fitting to the system, there will be more options than expected, as the actual shape of the winch will allow various options. Ideally, the cable should wind into the winch drum directly so that the cable will lay neatly on the drum. This is not always possible, especially with larger mains operated winches. In the example, the mains winch used an intermediate pulley which was fortunately supplied with the winch for doubling the pull on the hook.
Smaller winches can be mounted with the winch drum directly in line of the cable pull. The winch can be on the top of the rails, or if a compact 12 volt design, can even be on the seat if preferred.

Whatever winch mounting position is used, the mounting must be able to safely take the pulling forces. Therefore the ideal mounting for the winch will be directly into the ends of the rails, so the forces are direct into the rails and will not distort the alignment.

In this example, the winch gave a lift up the 12 steps in 15 seconds. This is about perfect, as most lifts are simply too damn slow for anyone, apart from those carrying a drink filled to the brim.

If the winch is too fast, then make a slower winch by removing most of the winch cable so that only the smallest diameter of the drum is used. Reducing the drum to a very small diameter will cause premature cable failure due to excessive bending of the cable on the reduced drum diameter, so this must never be done.
Alternatively consider a voltage limited or a speed controller from a similarly rated power drill.
(Alternatively use an intermediate pulley on the seat and use a double cable pull to halve the lift speed, although this is not very neat and has its own problems unless the seat is heavy.)

If too slow, then consider enlarging the diameter of winch drum by using a split wooden cylindrical collar under the cable windings. Do not use a much larger drum, as the manufacturer will have only designed the winch to be safe at this diameter. Only make a larger drum if the safety margin allows it. If the winch is only to be working at quarter load, then you may be safe to pack it out and double the normal winch drum diameter.

If you keep your eyes open and look around for a few months, the winch choice will be vast. The winch chosen here is the cheapest, is over-specified and cost 140 pounds.
This one came from a big red machinery mart, as available in most cities. They offered eight possible winches - six using 12 volts and three using mains electricity. They also have the occasional 'no VAT day', so keep ahead of the game when searching for your winch.
I have now seen the same item from a mail order catalogue for under 90 pounds - keep your eyes open.

The pull of the cable will be parallel to the rails and also check that the way the winch cable winds onto the winch drum must be positioned for neat winding.
The winch drum mounting must be positioned such that it imparts its force smoothly into the slider unit.

As the winch is not pulling the lift from a point close to the rail, then the winch should be mounted on an intermediate frame which pulls directly into the bottom and top rails rail.
Because of the square section tubing, a simple sleeved 'slot-in winch mounting' direct into the ends of the rails is possible, with perhaps some extra support to the floor.

In the example, the winch mount and the intermediate cable pulley is mounted on a simple steel frame which easily slides into the top of the rails and remain secure when in use, because the winch will tend to pull the frame into the rails. This makes a simple 'winch pod' which made final fitting very easy indeed.
When mounting the winch or an intermediate pulley, simply placing a bar between the two rails will suffice, if the mounting bar is strong enough. The thick-walled inch section square tubing is perfect for most uses.

Mounting the winch must allow for clearance when the seat is at the top, so always lift the seat to the top of its travel and block it in position, then you can start to mount the winch or pulley accordingly for a clean pull line of the cable and avoid any obstructions.

Larger winches cannot always be mounted directly in line and the example uses an intermediate pulley.
If making your own pulley, never make it smaller diameter than the winch pulley, as the cable may not like this degree of bending and distortion.

All winches use a similar mounting system, often based on a couple of U bolts. If intending to replace with a similar winch, then keeping to standard mountings allows for very easy replacement.
Never modify the winch unless absolutely necessary, as this may invalidate the warranty and make replacement difficult, both as a consumer and as an engineer.

When mounting the winch and any intermediate pulley, always do so with tack welds at first, so the mechanism can be test run with a light load to check for any obstructions or other problems. The winch should ideally be mounted using its original fittings, so making a standardised bracket or mounting tube should be part of the design.

When the winch is fitted, load the seat and check the winch works as intended. At this point you can still use the switch as supplied with the winch until the seat and cable run well. Perhaps the pulley is a tad tight.
There may be a need for a captive bracket to keep the cable wrapped around any intermediate pulley, and fitting such a bracket is always recommended.
Perhaps the winch drum is not perfectly aligned so the cable does not wind itself neatly into the drum, and perhaps the mounting may then need adjusting so the cable coils itself on the drum in a neat manner.
Also be very wary of the way the sliding wiring is routed, so that it will never be caught or trapped.
When testing, always keep your eyes and ears open.

When all runs smoothly, the winch mounting can be fully welded and secured in place, then tested with a full load.

Wiring the system.

On a 250 volt mains system, use a new fused connection from the main fuse box. If not possible, use a junction box on the upper ring main as this is often less loaded than the downstairs ring main circuit. This connection can then lead to a separate wall mounted three pin socket with a switch (and perhaps a warning light when on.)

If a 12 volt system, then an ordinary domestic wall connection will suffice, as the electrical load is minimal due to the gentle, constant trickle charging of the battery.
(A battery to motor fuse must also be added between the battery and the control switch or relays, to protect the system from any damage. On a 12 volt system, the fuse will be about 20 amps for a 200 watt motor, or about 35 amps maximum for a larger 12 volt motor, and will need suitably thick wiring. See below.)

As the example design uses a 250 volt, 500 watt winch motor, then it should draw something like a maximum of 2 amps and this was the fuse rating used for testing. ( V x A =W ) Later, a 3 or 5 amp fuse can be used to give a safety factor for long term use, without compromising the safety purpose of a fuse.

In the circuit opposite, the mains electricity is on the L and N lines.
The earth is E.
Live L brown goes straight to the motor.
The neutral N blue goes to the up and down switch, which then connects back to the up or down wires from the motor.
A large capacitor is placed across these lines, as supplied with the standard winch wiring.

Look upon the seat switch as connecting the power from the centre connection to the other two wires for the up and down power to the winch.

Safety stops.
Nobody can assume that the user will use the lift perfectly all the time, and so the winch may over run at the top or bottom. Therefore, in each of the up and down wires, you should place a micro switch to turn off the power at the top and bottom of the lift run. These switches can be placed and then adjusted to cut off the power when the seat is at each end of its travel.

Warning: Never fit the switches so they will be pressed against, to stop - as they will be crushed.
These switches must be operated by sliding lugs which allow the switch to survive even if the lift moves too far.

The easiest and most popular switch is the micro switch, which can include a metal lever which can be adjusted for perfect positioning. The standard micro switch is rated at 15 amps at 240 volts so will do for most applications and costs about a pound.

Micro switches.
These little devices can handle a lot of power and are also rather compact. they are available with or without levers, although the levers can be removed. The micro switch usually has three connections, an input, a NOT-ON and an ON connection. When pressing the lever or dimple, the connection switch over to allow either choice of switch use.

Because of their small size for the current they can control, micro switches can also be used for the users control buttons, as the micro switch arm can easily be removed, leaving just a small dimple of a button to operate. When two micro switches are placed side by side, and a narrow V shaped lever pivoted between them, then a simple 'up and down' control switch is created.

For end stop uses, the ideal micro switches are those with a metal arm, which will allow them to be switched more easily by a sliding action.
The stop switches can be mounted on the rails or on the seat.

When micro switches are mounted on the seat, they can interact with a metal tab welded to each end of the rails. As the control cable is on the seat, then wiring the switches onto the seat can make for easy disassembly.

In the example, the micro switches are mounted on the rails, with a pair of passive metal fingers on the seat unit to switch them off at the ends of the travel. Next time, I will place the micro switches on the seat to keep the amount of wiring down to the minimum.

The wire from the switch for the up connection goes to the winch motor via a micro switch, which prevents the lift going upwards any further than is needed.
Similar for the down wire.

The microswitch levers are actuated at the appropriate position with simple metal tangs welded to the structure, so they can be bent to give perfect stop position adjustment.

The mains wire should lead to the junction box in the winch mechanism, and from this some extra EARTH cables lead to the main rail and the winch body.

It is vitally important to earth the rails and metal parts of a mains voltage system.
No earthing of mains electricity = no permission to use.

Always make sure the winch body is earthed and is directly in contact with the metal parts of the rails. If anything should go wrong, the power will tend to flow to earth, not to the user.

From the junction box on the winch motor, the three core control cable should be a single, long length down to the seat at the bottom of the stairs. Do not join wires to make longer ones, as this can cause problems later. Such cable is not expensive and easily to made into a coil over a broom handle and heated as mentioned above.

If the winch comes with a control device, then this can simply be extended with a longer length of cable and simply fitted to the lift design, but does not always make for a better design.
In the example shown, the original garage control switch included a large capacitor which was removed and placed compactly across the appropriate wires of the winch motor. This then allowed just three simple wires to the control switch.

As this switch on the armrest is running at 240 volts, the connections to the switch are insulated in the wood armrest just to be extra safe. The whole lift system was wired to earth from the mains socket, should there be any breakage in the wiring. The whole design was also earthed via the metal frame and the alloy casing of the winch motor.

For extra safety on mains voltage systems, you may wish to add a commonly available safety RCT 'residual current trip' as used on electric lawn mowers, should a cable become damaged: Highly Recommended.

On 12 volts systems the circuitry can be easier and safer and not too dissimilar. The same wiring of control and stop switches and such like, with much easier motor wiring from a 12 volt battery with a simple battery charger attached to the mains wiring.
WARNING: The main problem with 12 volt systems is that the wiring must take many more amps to power the winch. 30 amp wiring is rather thick, so it is highly recommended to place the winch under the seat, along with the battery, so that just the sliding wire for the power supply need only be a small, thin wiring to take the much smaller current needed for charging the battery.
The heavy power current and wiring between battery and the winch motor can then be done with the thick wiring, which is all kept neatly under the seat.
The switch for a 12 volt system can either be a high current switch capable of about 30 to 40 amps, or use relays and a much smaller control switch or switches.
The battery charger can be either at the top of the stairs and feed the battery via a small wire, or to have the charger under the seat.
If the charger is mounted under the seat, then use a small, coiled sliding, three core mains power cable from the wall socket to the charger under the seat.

In the picture, the microswitch lever is positioned such that the seat unit will press against the lever and prevent further upwards winch movement. This switch is mounted on the rail rather then on the seat unit, but does just as well the other way around.
The picture also shows the winch cable pulley, which is positioned directly over the centre of the winch drum. This will enable the cable to wind itself neatly onto the drum to prevent bunching or a subsequently notchy ride.

The switch position should be such that it is away from dirt or fingers and preferably hidden to prevent damage.
The lever on the micro switch will allow a couple of millimetres travel before switching off, and so the lug should be mounted such that the operating finger on the lift runs along the lever to switch it off.
Warning: If the micro switch was mounted to face the oncoming lift, it could be crushed, causing many problems. Always mount the lever such that it remains safe and can be adjusted for a perfect stop point. This is why the lever action microswitch is particularly good for the purpose, as having an adjustable (bendable) operating finger makes final adjustment very much easier.

Always check the cables run freely in the up and lowered position. Yet again, slide the unit up and down the stairs many, many times to check the electrical cable runs freely and smoothly. The cable run is most important as it carries the power. If mains operated, then this is extremely important to check for any potential damage. Be particularly careful where the electrical control cable is compacted at the top of the stairs, also at full stretch at the bottom of the stairs. Make sure the outer sheath of the cable cannot be rubbed bare by the winch cable or by obstructing with the rails.

The winch can now be wired up using the standard supplied controller for initial testing, and the controls checked for action. When operating correctly, the winch circuit can be made, mounted and the lift tested.

As the winch can lift far more than needed, test the lift with a dummy load many times and fettle the action until perfect. With the winch working, look for problems. These will be far harder to see, as you do not have the feedback of your own muscles telling when things get tight or break, squeal or creak.

With the winch loaded, use a smaller fuse than the minimum rated. Then test with the max load and check if the under-rated fuse blows. Once working happily, you may wish to leave the lower rated fuse in place for the first few weeks until all is sorted and fully checked. When fully confident, you may wish to step up to the next fuse rating for a degree of long term reliability.

In the example, the 240 volt winch worked happily with a 2 amp fuse and this did not blow under fully loaded testing. Therefore the 2 amp fuse was left until it blew, to see if the rating is adequate. (After a few years 2005 to 09) The fuse has not blown to date, so the 2 amp fuse rating will remain. The 2 amp fuse could feasibly blow if the winch was loaded to its full rating, but as this winch is only asked to pull a quarter of its rated load, then a 2 amp fuse is ideal.
If I was not around to maintain the lift, the fuse will be replaced with a 3 or 5 amp fuse which will still protect the design more than adequately, but not cause problems. This also applies to a lift where the user may become stranded, so a blown fuse failing because of old age is not acceptable. Always replace fuses yearly on such devices.

In a 12 volt system the fuse rating will be much higher unless a very slow winch is used, because Volts x Amps =Watts.

Always leave a couple of spare fuses nearby. I stick them somewhere convenient with some blue tacky adhesive putty as used in offices. In this case, they are stuck above the three pin wall plug, along with a tiny screwdriver.
A thermal trip fuse can be used if preferred and makes for an easier life when something untoward happens, as this allows the tripped fuse to be easily reset.

You now have a basic, mechanically and electrically working stair lift.
It is not yet ergonomically sorted, NOR necessarily safe to use.

Controls and Ergonomics

If a wheelchair user, the bottom and top seat height should be matched to the wheelchair. A couple of smooth, varnished plywood shuffle boards can also be used at top and bottom of the stairs to slide between wheelchair and stairlift seats. These could be like small transfer seats at top and bottom, built to be perfectly level with the seat unit.

The users feet must not be allowed to hit the steps, so the user will often be pointing away from the stairs, then be able to turn to face the stairs when at the top.
In this example, the stairs were particularly narrow, so the user sat with the feet pointing down the stairs.

A pivoting seat base from an office chair may be suitable for some users.

Shock loop.

If your winch is too jerky, then add some form of shock absorber, such as a spring loaded hook. Always include a strong metal fail safe loop to the winch cable which must keep the lift working should the shock absorber or spring break.

In the example shown, the winch cable connection was allowed to slide on a strong bar and is restrained from the full pull position by a spring which was in the form of a bungee. The use of a bungee cord is that it can easily be tensioned to match the user load.
The bungee allowed a smoother start and stop to the lift action, without compromising safety. If the bungee should break, the lift cable will work directly on the mounting, and the lift will continue to work without the shock cord.
The shock loop acts by reducing the initial jerk on the winch which will also improve long term reliability of the machinery.
The stopping at the top may also be jerky, but the shock loop helps reduce the deceleration. The position of the micro switch lever helps the final position of the chair at the top of the lift rails.

The loose shock linkage was made from mild steel bar, bent to shape and welded. The bungee cord was available from a camping and caravanning shop. (Plymouth - Union Street.) The number of loops of bungee cord was adjusted to allow a reasonable movement by the weight of the user.
Too many loops of the bungee and the shock cord was tight and unforgiving. Too few, and the shock cord may as well not be there. The load was applied and the bungee cord was used to take up the tension on the cable until the load could just begin to move. The bungee was then neatly arranged and secured.

Where a winch is mounted in the seat unit, then the shock loop will be mounted at the top of the cable run, where it is secures tot he upper frame at the top of the stairs.

Testing 2.

Slacken off the winch cable for the equivalent of three steps and slide the chair up past the bottom step. Using gloves, pull on the winch cable to lift the safety device, then suddenly sit in and release the cable to check the safety device works correctly. Do this three times to check.

Always make sure the winch housing does not collect dust and any overheated motor cannot catch the house alight. If in doubt, use fireproof cladding around and under the winch, but always allow plenty of ventilation for the motor.

Testing for reliability.
12 volts:
If a 12 volt system, fully charge the battery, disconnect from the charger, then see how many runs are possible on a single charge.
Warning: When the lift begins to slow, immediately stop and recharge fully to prevent battery damage. (See also the companion batteries monograph on my website.)
If you have lots of mains electrical power supply failures, then use a deep discharge battery. These are more expensive, but allow the battery to be run down fully without serious damage. Otherwise, just use a car battery for cheapness and ease of replacement.
There are also many affordable solar battery chargers now available if needed, often in Ships Chandlers, but they are rather expensive and sensible alternatives are available if you look around.

Testing for reliability.
Mains 120 or 240 volts.
Check for any overheating of the cables, the motor and the control circuit. You may wish to use a multimeter to check the current draw on the motor. A 10 amp multimeter will give good insight of the electrical loading on the motor. If you wish to add a load gauge to the design, then a simple AC ammeter can be included, then marked appropriately using the test loadings.

With the loading checked, the fuse can be chosen for safety.
If a 12 volt system, always fit a fuse between battery and the winch motor to protect both. A 12 volt system will need a larger fuse rating. (V x A = W). E.g. a 120 watt 12 volt hand drill motor needs 10 amps.

Testing for ergonomics.

Use the lift using all possible disabilities. Make yourself almost impossible to use the lift, acting as if very infirm and then take careful note how the design could be improved.

Testing against stupidity.
Try to break the lift using ordinary everyday forces.
Then step up the level of stupidity and use minor vandalism. Act like an idiot now, to prevent stupidity happening later.
Make changes appropriately.
If children are present in the house, always include a lock switch in the circuit, high enough not to be used by kiddies, but accessible for the user, and perhaps to disconnect from the electricity when not in use.
As some modern 'Blair' kids are almost feral, then add a lock and key switch.

Long term reliability.

Replacing cables.
The steel wire winch cable must be inspected fully for damage every six months, and more if used many times a day.

It is only too easy for an idiot to check for broken strands by running a hand along the cable but this will surely cause skin damage, so do not be tempted. Scrupulous visual inspection and gentle touching is preferred to check for broken strands.
Cables have a safety margin, so two broken strands near to each other is almost acceptable, but preferably be wary beyond this. The strands are often caused by poor winch drum and pulley runs.
If the cable is damaged, the winch drum may have plenty of spare wound on it. The cable can be cut at the last point of damage, then the unused cable payed out and reattached using the cable loop eyelet. In some cases, it is only necessary to discard the cable from the last weak point, but for long term safety, using the previously virgin, unused cable is preferable.
When the cable needs fully replacing, then new cable is probably available from the place where the winch was bought, as it is not expensive.
New cable hooks or securing loops must be attached with eyelet and new clamps fitted. Always use the correct clamps for the cable.

I always rub my winch cables with plenty of candle wax, so that the rubbing is minimised and the wax acts a lubricant between the stands as they flex over the pulley and winch drum.

Replacing switches.
Not all switches can be bought the same day they need replacing. So always keep a spare switch for each item used. They are not expensive. If the switch becomes unreliable, buy a replacement and a spare, so it can be replaced immediately.
In the example, the switch is in the removable armrest, and connected using a domestic 3 pin in-line plug for easy servicing. (I switch off, disconnect the three pin plug and arm rest, so that repair is very quick and easy.)

This is another advantage of not buying a commercial stair lift, as the cost of calling out an engineer to 'rip you off' is eliminated and repair is far quicker and at minimal cost.

Footrests.
No footrest has been added in this design as it takes up room and can cause more problems than it's worth. A footrest can trap items such as shoes or clothing between the footrest and the steps. If wanting a footrest, then it must take the users weight and not flex under load. An alternative lightweight foot rest rail could be used just to keep the feet out of harms way and such that it can NEVER trap a foot between footrest and stairs.
If making a footrest, try to design the pivot so it can deflect AWAY from any item left on the stairs, as if obstructed by a walking stick or whatever. A folding, lightly spring loaded design is recommended to allow deflection from obstructions.
If potential problems are possible from obstruction with a foot rest, then ALSO include a cut-out switch on the footrest, to the control switch so that it works in both directions, up and down the stairs. Such a cut out could be a simple edge bar mounted on a hinge, and acting on a micro switch to the central control wire to the rider's control switch. Alternatively, a pressure switch with a pneumatic rubber edge tube could be used.

Improving safety.
Because this is a simple design, the following could be considered.
The bottom position is a simple roller stop and so the cable will simply slacken, therefore no electrical cut out is really needed, as the winch cable will simply slacken for a split second until the micro switch acts.

The lift should not be used without the armrest in the up position. If the controls are mounted in the armrest, then this will be self effective and not need any fancy safety circuitry to check the armrest is in the safe position.
If the users wear long, flowing dresses, then these must be carefully checked and the mechanism designed to prevent these getting trapped in the rails. Some simple large panels of cardboard can do this job really well as a cosmetic cover between the rails and the seat.

It may also be applicable to include a small lamp under the seat base, to illuminate the foot area for increased safety or perhaps just a little extra style for night time use.

Improving the concept.
Such a lift need not only carry people. The design shown also makes a very good heavy suitcase carrier, as the seat is wide and the arm can be folded up, yet still operated by a fit person who simply need not carry a heavy load up or down the stairs. In this form it can become a load lift, with a person walking beside it.

As the switch in the arm can be operated from both sides, this also makes a moderate exercise machine for walking up the stairs, using the armrest for support. This does not work easily going downstairs, but going up, this makes a good support device for the frail who wish to exercise going up stairs. Going back down the stairs, which is far more dangerous for the frail, then the lift should be used only as originally intended.

As this design is narrow, light and home made, there is room for some bits and pieces to liven up the design once the basic design works reliably and as required.
Ideas can include electric drill control switches for speed control and reverse switch of AC mains items, or similar for the lower voltage DC rechargeable drills.
The seat can be restrained in the folded-up position with a simple elastic strap, a simple side hook or some hook and loop fastener. Likewise the armrest, although if an amount of friction is introduced into the pivot, such as a spring loaded clip or threaded adjuster, then the seat and arm rest can be more simply restrained by friction in the up position.

In the example shown, the bottom seat lug is offset and this gives a suitable amount of fiction in the tube and slider, so that the seat stays up by itself. Likewise the armrest has a slightly tight securing nyloc nut. If it loosens, then a little tightening on the nyloc nut keeps it all well.
Perhaps consider a wall mounted shelf beside the lift to hold a cup of tea while getting in and out. Also walking stick holders and a bag carrier hook which will allow a bag to be carried safely.

Finishing.

Styling can be anything you desire. Not only the slider, but the winch cover and other bits and pieces.
The overall shape can be disguised using cardboard covers or wood or blocks of rigid foam. Cardboard may seem frail but unless protecting mechanical components from strong physical intrusion, cardboard will easily help tidy up a design. Where mechanical protection from accidental finger or walking stick intrusion and such like is needed, then thin plywood is excellent.

For sculpted shapes, foam blocks can be bought from building suppliers and takes the form of large white or blue foam sheets used for insulating roof and wall spaces. This blue foam is easily carved and sanded to shape, to allow easy sculpted shapes. Carve the sheet to suit and fit, then shape to a rough profile using a bread knife. Then sandpaper to shape and paint. Check the paints on scrap pieces as some paints may dissolve the foam. When dry, the foam blocks can be simply and lightly glued, just enough to hold them in position.
If the shape is nice, then it can be covered in cling film, then given a coat of fibreglass and the foam removed afterwards. The fibreglass can easily be held by hook and loop fasteners or thick rubber bands cut from old cycle inner tubes. The advantage of non fixed retainers is that if anything goes wrong, such as slipping off and getting a finger caught, there is less chance of injury to the user.

The upper winch pod can be disguised with a covering or box and perhaps include a small shelf for a potted plant or such like, or in this case, to take a cuppa.
In the example, the upper rail was de-waxed, then both rails and winch and seat were painted. When the paint had dried, the upper rail was re-waxed on the wall side with a candle. The winch is covered in simple cardboard and wood effect plastic sheet, as this is all that is needed for the purpose. If the cable ever got caught, the cardboard would do no harm. Likewise a small shelf helps protect shins from hitting the top end of the lower rail. The black metal work will be repainted with a medium brown to blend passively with the surroundings.

As seen in the picture, the folded seat and armrest at the bottom of the stairs can be seen as being well within the width of the bottom rail. The narrowness, reliability and low cost are the main design criteria and were done for under two hundred pounds. No problems whatsoever have happened once the design was fettled to allow the cable to wind neatly, and a couple of creaks and squeaks removed by waxing the upper rail guide and waxing the winch cable and intermediate pulley pivot. It was then finally tested yet again and again until completely satisfied with the design.

As of writing, the lift has been used for four years with no problems whatsoever.

That's about it.

I hope this monograph has helped you think that spending many thousands of pounds is not worth it.
It is often better to spend the money on building your own and thereby saving a vast amount of your money for yourself. Admittedly, you will not have such a fancy lift design, but it will be tailor made to your height, your stairs and your colour scheme. And the mechanic will always be on hand.
As many people simply cannot afford their own stair lift, yet need one, then have a go. Even if it takes a few months to build it and perhaps get a friend to help, you will have at least have had a go.
By not buying the winch until you have built the lift, then you will only have lost about fifty pounds. It is not difficult, and if welding is not your expertise, then simply tack weld and get someone else to do it, as there are still many old engineers in the country who will be glad to use their many skills.

I am designing an even simpler design of stair lift, using wood and basic skills, so e-mail for details if you find the above example a bit too difficult or inappropriate.

Here are some other bits and pieces below which may help with the process:

Alternative designs 1.

No electricity?
A balanced weight system.
This design uses a counterweight half that of the user and lift unit, so this counterweight can slide as a large metal block or metal container with concrete or other heavy bits, sliding just inside the lower rail, on a simple channel runner or beside the skirting board. This allows the user to lift themselves up by pulling on a knotted rope, and only needing a pulling force of about a quarter of their own weigh. (It would be half their weight if moving vertically.) This is not recommended for most people as the effort is long and hard.
Without a counterweight, the pull is half the weight in a 45 degree slope and with the counterweight, it is only a quarter.
As only a quarter of the users weight needs to be pulled, there is the need to put a retaining catch at the bottom of the seat position to prevent the seat being pulled up the slope by the counterweight when the seat is empty.

If pulling on a knotted rope is not usable, then perhaps a simple winding hand winch can be used. Perhaps modifying the crank or cranks of a pedal cycle to work a single or double handed hand winch.

A water lift system.
This is a better design of the above counterweight system, especially where water is commonly available, but no electricity. The weight of the user is attached to a cable looped around an upper pulley, then back to a water tank which slide on the other end of a winch cable.
When the tank is empty, the seat will be at the bottom.
When the tank is filled, the heavy tank will descend, to pull the seat and rider up the slope. As the tank is filled, the tank will begin to counter balance, then gradually lift the seat uphill as the heavy tank descends.
Instead of a control switch, the sliding counterweight tank is filled via a tap and pipe, or a remotely controlled, spring loaded lever tap, pulled open by a long piece of string.
As the water balances the weight of the lift and user, the lift will rise up the rails and then the tap can be turned off.
When wanting the seat to go down, the tank is allowed to slowly empty, by pulling out a spring loaded plug in a small hole.
A long, spring loaded rod or cord to open and close the water tap can be run on the wall beside the rails.
In reality, the tank need only fill and empty just a little more than the weight of the rider. The tank will be pre-loaded to just slightly lighter then the bare lift unit, so the bare lift slides down easily, with just the addition of enough water to overcome the mass of the rider for lifting purposes.
The ability to empty and fill the tank will need a long, flexible pipe, controlled by a tap at the bottom of the lift. Draining the tank slowly though a small bore pipe will need a small tap on the bottom of the tank, but accessible from the top lift position, perhaps just an easily moved plug or sluice.
This can get messy if indoors but with careful plumbing and drainage, can work cleanly. Perhaps the whole system could be contained inside a long plastic pipe or large plastic guttering.

Alternative designs 2.

For many people, a simple moving step is possible consisting of as simple fold down foot flap or rubber covered motorcycle foot rests, so the person can walk up to the slider, step on and grab a handle with both hands and press one button to go up and other to go down. This would allow the person to remain upright at the top and bottom of the stairs but only suitable if the user is adequately strong. (Not unlike the moving steps of old mines, where the pump rod moved up and down, allowing miners to step on and off to go up or down the main vertical shaft.)
A good design is to simply copy or modify the earlier seat lift described above, with bottom and hand rail on just one side of the stirs, and remove the seat, then simply add a small foot platform which can be folded up when not in use. The add a grab handle with easy access to the switch. This way, you can simply walk to the lift, stand on a basic foot rest with rubber anti slip mat, grab the handrest, then ride up or down as needed.
If standing, but a tad frail, then adding a bum-rest, as seen in some of the awful modern commercial bus stops, could be used to lean the bum against and help take some of the initial shock when starting up the stairs.

The vertical lift.
Where there is no room for a stair lift, a pair of parallel tubes can be used to allow access to the upper floors. If the user is prepared to stand, then this can even be hidden inside a small corner cupboard. If siting, then a larger cupboard may be needed to hide the device.
Two guide rails running vertically can allow a simple one-person cubical to be lifted. The safety mechanism must be very carefully designed and made to prevent problems if the winch cable fails.
The long cable runs will allow many floors to be accessed. There may be a need for a trap door to be used for safety reasons if it is of an open plan design.
The user must never be able to allow their arms or head to be struck against the rest of the house or ceiling or floor while raising or descending, so a simple lightweight plywood box with door, not dissimilar to a shower cubicle, will allow reasonable safety. The neatest I have seen is a large plywood box with plastic windows which can simply fold flat against the wall.
Such a system must NEVER be made unless a truly reliable emergency exit is possible should the lift fail between floors. Such a safety feature could be steps beside the rails. Never rely upon an emergency phone, although this can also be useful. the stories of people being stick in lifts for days attest to the all - pervading failure of electricity.

A wooden lift.
A British chap emailed me recently as he had plenty of wood available and considered this as a building material.
If a wooden framed house was good enough for Shakespeare, then a wooden lift is good enough for me.
The main considerations with wooden frame is the strength. In this respect, it's the upper support rail which is the main area of concern as the weak point. Fitting wall brackets every foot or so is recommended.
The rest can be easily made in wood, apart from the rollers and individual winch components.
Wood also ensures the mains power is safely insulated, so the micro switches and such like remain insulated and far safer than a metal structure.
The upper rail must be strong, and for this reason, it would be best to be supported on a steel angle V channel, as this simply makes life easier. If using small metal V channels and joining them together, then this is best done with countersunk bolts with the wall mounting brackets to give a neat and flush fitting mounting point.
If no welding is available then the upper rail should be one long piece. Where a single long piece of wood for the upper rail is impossible then join two or three long pieces of suitably strong wood. These joins must be nicely stepped or tapered. A stepped joint is best as it ensures better alignment over time. Such a step join should be rather long and strongly glued together as well as screwed, then planned and sanded to a good finish.
The upper sliding runner which slides over the upper rail is problematic, as it must be suitably large, but a long piece of plywood suitably fixed to the upper part of the seat slider should not be a problem if screwed and glued strongly enough and then waxed to allow it to slide easily. The upper rail slider must be restrained from coming off the upper rail and must never come off the rails under any circumstances, even when the safety stop is used.
Fitting the wooden rail to the wall will probably still need metal brackets and these must be fitted such that the guide rail cannot come off. Therefore the wall brackets must be made in metal and sunk to into the wood to be flush fit, so the rail guide can slide neatly and safely.
The rest of the upper rail is a described above as for steel, but needs an inch and a half, to two inch wooden rail for strength and preferably of unknotted wood, which has been left for a year or so to season, preferably in the house, then planed to side and polished. Because it has a rather large size, the upper rail can be smoothed to make a reasonably comfortable hand rail with rounded corners.
The lower rail is a simple copy of the upper rail but must take the whole load on the wooden rail. Using skateboard wheels which have been cut down to be narrower, will prevent the bottom rail from becoming dented over time. The central bearings of skateboard wheels are small but reasonably capable of taking the load and the plastic which overhangs the bearings can be easily sawn off to make a large diameter, narrow bearing which is easily replaced when it becomes worn. Because the skateboard rollers are larger diameter, then the lower side guide rails will also be a little deeper and can be made from plywood.
A wooden seat should be easy, although stout wood is needed for the frame and strengthening blocks and good screws used to glue and screw the structure neatly.
The advantage of wood is that the rails can be sanded or planed to slide easily, rather than to exact engineering of a metal frame.
All other parts made in wood such a bottom stop and winch mount should also be of stronger wood and where the winch is mounted, with plywood triangular strengthening pieces at the joins.
Do not cut into or tennon the main triangulation pieces of the sliding frame, but always screw and glue cross beams to the side of the wood to ensure strength above neatness. Adding plywood triangles across the joins also helps make a rigid structure.

Again, testing should always be to twice the expected load, then refined to slide smoothly before fitting the winch.
Where the winch is mounted to the rails then this could be a wooden box with plywood sides to offer extra strength. The winch mounting can be a simple compression mounting on the upper ends of the rails with the pulley in the centre.
Where the high stress spots are, then they must be strengthened with extra wood or plywood, such that the forces resolve into a safe part of the structure without any chance of breaking or distorting with time.
Where the winch cable fits the sliding seat, then this should be doubled up with two strips of strong wood or plywood to ensure a strong mounting. If a wooden cable box is made along the seat, then the cable spring bungee can be replaced with rubber blocks along the winch cable to take the shock load into the seat.
ALWAYS fit a fail safe safety stop device should the cable fail.

All wood should be lacquered and polished before employing any wax to the sliding areas on the back of the upper rail. A wooden stair lift should also look nicer and blend in better than a steel version.

I have used the word 'strengthen' quite a few times in the above section and this is the only real cause for concern, so always play safe. Copy the steel design if you wish, but with thicker wood and strong, if not fancy joins for the various places where welding is used. The final design need not be significantly wider than the metal version.

Outdoor Rails and death slides.
An American emailed asking how he could get to the beach from his cliff house. At the time I could not offer much advice, but on subsequent pondering, I offer the following possible solution.
If a rail system can be made, or an overhead cable slide, such as army death slides, then the user only needs a power source to get back up the hill. This can be easily done with a moped engine and a winch drum. As the engine is compact, and a winch drum built where the rear wheel would be, or even made from the bare rear wheel rim, then a reliable moped such as the old 50cc Honda Melody or similar one-piece engine and rear wheel design can be used. This also offers electric start, a good brake and variable speed transmission. The engine can be connected to a long cable to pull the user up the hill, and the brake used to allow the cable drum to unwind slowly down the hill. If a rail system, then the engine and drum can be under the seat, or of an overhead cable, then the engine can be part of the overhead roller system.
By using a suspension wire, to hold the rider and engine weight, then a second wire can be strung alongside, and wrapped once around the bare scooter rear wheel to act as a drive drum. To go up, use the engine, and to go down, use the rear brake to control the descent.
Such a two stroke can be run in any orientation, if the carburettor is aligned vertically, although an upright engine is preferred, with a simple passenger steel frame or nylon webbing harness secured to the engines' large scooter frame mounting points.
Of course, if a small, if somewhat steep track is available then simply use the complete moped and add stabiliser wheels if needed. Mini quad bikes are also now available although Chinese and not always as reliable as one would wish, as I have had to fix far too many new ones.
As the moped brake can wear or fail, or the winch cable break, then there must always be a safety device such as a separate brake on the rail system, or a friction clamp on the death slide.
These engines have kick starters which can be replaced by a more easily used handle, where the user can pull sharply on the lever a few times to start, usually using strong upper arms and one hand on the lever and another hand hold on a secure engine mounting bracket. Or use the electric start versions with its small attendant battery and in-built battery charging ability. The battery should be charged regularly, about every ten uses, or connected to a trickle charger when parked near the house. Batteries should be replaced every three years.
The automatic choke and petrol tap and a small fuel tank and two stoke tank can be easily fitted, or simply use a single fuel tank and use two stoke of premixed oil and fuel about 12:1 fuel to oil. The throttle can be easily controlled with a simple lever or pull cord. The motorcycle rear brake which is concentric with the 'winch drum' should be held permanently in the braked position, with a push bike brake lever used to release the brake against a strong, fail safe spring. If levers and cables are not your strong point, then simply fit small push bike control levers directly to the engine throttle cable and to the rear brake lever.
I highly recommend making a direct fitting rear brake lever which needs to be pushed to release the 'winch drum', to move up or down the slope. When the brake lever is released, it can also open the throttle for riding up the hill. This would be a rather good fail safe design, as letting go the lever would apply the brake and slow the engine to tick over.
All such engines should be protected from the elements and covered in a plastic cover when not in use and must be regularly maintained. All death slide cables must be loaded using a fail safe weight on the upper or lower support, to maintain tension. All cables must be cleaned, greased and inspected monthly, often while moving up and down.
If I were building such a death slide, I'd go to my local government surplus store and use the strongest stainless steel marine grade wire stop as the main rail ensuring it was heavily overpriced for the intended load, as the cost would be well worth the reliability. To reduce costs I'd use smaller marine cable if available, or standard winch cable wire as found in local DIY stores, as it would be housed under a roof or enclosure when parked.

Other options.

Look to fairground fun rides for all possible options, as most things in life have already been invented before.

More ideas may be added later, as and when I get around to thinking about the options.

If the reader has ideas or problems, please feel free to email.

Email the Author at jhpart@btinternet.com

There are many ways to make a lift.
Making a basic lift does not need a high degree of engineering componentry.
The fun theme parks and their rides have shown that it is not just stair lifts which can move around a variety of spaces heights and in various ways.
Until someone invents the antigravity pad, - always keep your eyes and mind open.

Winches are mentioned above, but the use of long chains from motorcycle suppliers, and the appropriate sprockets can allow a low geared motor and gearbox to make a different form of lifting device. When the sprocket and chain are laid sideways, then the lift can turn corners. For safety, the lift should ideally be connected to the chain, and the sprocket on the winch, with the chain wrapped around half of the sprocket to prevent slipping.
Cables can also turn through corners, but will need restraining devices to ensure they lay in the correct and safe positions.

For a compact and easily replaced power source with speed control, the use of industrial grade 800 watt mains hand drills and their controls allow a much wider selection of options. Using these as initial testing devices, especially the many discarded items will allow the experimenter to have a good selection of suitable components for making prototypes.

Helping others to build a lift for a far better world.

Like the increasing numbers of money grabbing lawyers and politicians, be wary of people who want everything for nothing, as they are on the increase in modern British society.

Also be very wary of lawyers ! NEVER build a stair lift for people, but only build one which can carry large items such a plant pots the same size and shape as people. Always get the person to sign a waiver and disclaimer before you do anything. This way, you have not put their life in danger and the modern vast hoards of parasitic lawyers will not appear so easily.
If the relatives of the user find a problem, they may get nasty, even though you have the most honourable motives for helping.
In modern Britain, where nobody seems to care, - cover your arse from parasitic lawyers and EU directives !

Be ye warned:
In Blair's Britain, a woman gave a dinner party at her house for close friends, and a chair broke. Then she had a lawyers letter stating she may wish to settle out of court and pay thousands of pounds for the slight injury to her 'friend'. Welcome to the appalling mess of modern Britain.

It is a shame that everyone must 'cover their arse' rather than to help others, but this is the problem of the many bad lawyers who are running and ruining British politics.
Lawyers now make a nastier world.

Nevertheless, there are still a few wonderful and nice poor people out there in Britain and the rest of the world.

Don't be cynical, just be wary and ALWAYS vote to keep lawyers and assholes out of politics.

WARNING:

Finally,
Please feel free to offer feedback for better lift design and genuine affordably for all who are disabled. If you have any help, advice or criticism of a decent nature, please email. If anything needs adding or is left out, then I will happily update this page.

Welding.

Unless you are a natural born welder, expect to get frustrated for a few weeks until the skills are gradually acquired and you eventually get the feel of welding. See my website for the companion welding monograph.

Seat covering.

Keep all screws flush and never fit any accessory or item which will impale or damage the rider.

There is no reason why a machine cannot use Connoly hide and have polished walnut trim. Again, keep the original seat covering for the leather worker to use as patterns to match any standard seat foam. The JP7 had this as an option.

Specification of the finished stairlift design.

The time to rise up the 12 step stairs is 15 seconds. Likewise the same time to descend.
Angle of incline: 44 degrees from the horizontal.
Widest part when folded is the lower bearing support rail at 7.2 inches off the wall.

This lift has been working now for four years without any problems, other than the need to keep long skirts way from the rails. For this, a strong cardboard cover made from a cooker packing case is now used over the lower rollers.
The rails and seat unit have settled down and have shown no problems with distortion. I have tested the rolling action of the lift for any tight spots, but it has settled down to its working use quite happily.
The folding armrest has been modified with a nyloc nut, which can be tightened to allow the armrest to stay in the upright position when folded.
The upper micro switch could be touched by the bare hand over the electrical connector causing possible electric shock so has been replaced with fully shielded connectors and a large dollop of silicone sealant to prevent human contact.
The lower rollers squeak a little on the up movement.
There has been no visible wear on the winch cable nor on the electrical cables. I have waxed the upper rail and the winch cable a few times using an ordinary candle and these have settled down to a quiet sliding action with no abrasion and the upper rail also act perfectly well as a hand rail.
A strong vinyl carrier basket which folds out under the seat may be added later, to allow small items to be carried more easily.
A cup of tea spilt during tests, so a cup holder will not be fitted unless a cap to cover the cup is also provided.

Since building this, I have noticed that it is possible to make a much simpler 'stand up platform', so the user can simply walk up to the base, then stand on a basic foot rest and grab a vertical handle without needing to lower the seat. A simple folding motorcycle footrest is added to the bottom roller and the backrest becomes a hand grab. Then press the lever of the vertically folded armrest to ascend or descend. This could become a minimalist form of the slider unit and would only need a small, non slip, spring loaded, folding foot area of about seven inches square which would fold out level with the ground and the upper step. A lip to prevent the feet getting caught in the stairs may be needed when ascending. The advantage of this is that there is no palaver with unfolding a seat and sitting down. - Just walk up to the lift, step on and go. The foot plate would need to be spring folded up when at the top of the stairs, to prevent others from tripping over the extended top step. For elderly or infirm, a simple, lightly sprung foot plate which is normally in the up, folded position and a strong grab handle would suffice.

With use, I have not bothered to sit down, but I simply walk up to it, kneel with one knee on the seat to maintain my upright posture and use the control on the up folded armrest, to easily move up the stairs without having to sit down.
I always recommend walking up stairs wherever possible to help keep fit.

Environmental impact study.
(For the Euro - tossers who want more paperwork and fewer trees.)
The design uses simple components with minimal machining and forming to keep energy of production extremely low. The use of hand tools further improves this energy efficiency and reduced investments in corporate tooling processes.
The steel uses energy to mine, carry, crush and melt the steel ore, plus recycled metal. The rolling, forming and seam welding requires further energy. Likewise the winch and electrical components. The winch also needs a factory to machine and assemble the winch. Because the winch is a standard component, its mass production makes if far more efficient to produce than specialist components.
The electrical cable is domestic standard plastic insulated with copper core and likewise economically produced. Some fumes were produced from the arc welder during manufacture of the lift itself.
The design produces no pollution while in use, other than that caused by consumption of a small amount of electrical energy at the power station.
If a 12 volt winch was used, then this could be powered by a solar panel, but would incur the need for a chemical storage battery with it's further attendant needs for manufacture and recycling.
All components can be recycled.
End of the political clap-trap.

There is no such thing as global warming, merely another interglacial period similar to that following the Holocene.

Apart from being a tenth the cost when compared to a commercial design, this lift is far more economical in use and in the use of plastics, having a much lower count of unnecessary plastic styling components. The design uses much less material and is this recommended for those who wish to limit global pollution.
For countries with high rainfall, then a hydraulic design would be even more acceptable.
See also water and wind power monograph on my website.

A shopping list.

This comes to about 150 pounds without the 40 quid welder. Not too bad for a custom built, narrow folding, made to measure, high speed chair lift.
The winch motor is nowhere near its working limits, so likely to last forever with its integral fan and cooling fins. Similarly, the winch drum has enough cable wound on it for three replacements, so should last for many decades.

If you are making a design to fit into an old house, then check out Woolies who outfit classic cars.
Woolies. Whitley Way, Northfields Industrial Estate. Market Deeping. Peterborough. England. PE6 8LD. All the fittings for the traditional design. Rubber window strip, carpets, headlining, brass and chrome fittings for vintage and classic motor trim and a host more. http://www.woolies-trim.co.uk

End.

Begging.
Begging is the bottom line of this work. Being just one of the many long term unemployed English science graduates and qualified teachers with a strong engineering background in nuclear, marine and other spheres, the author would like a job. Teaching technology or science would be most tempting. I have a letter from a local board of school governors, saying I'm not qualified for a part time lab technician ! (Freemasons again.)

Most of the vast numbers of 'begging bowl innovators' like me have wonderful ideas, so please help. Volvo have jumped me on two of may patentabel ideas. British venture capital is unfortunately an oxymoron, a joke comparable with our railways and education system.

Gizzajob.

I have been told by government careers advisors to become a cleaner.
Like many British graduates, I have resigned myself to being poor, but I still think I deserve a little better than that for many years in universities.
Unfortunately more than half the new swarm of graduates will also be ending up in crap jobs.
Many people are now getting fed up seeing all to often a country where the indigenous population are doing the crap jobs, while immigrants are actively grabbing or being offered the better jobs by government officials.

Send 'em home to make their own country better.

Britain is going down the pan.
Thatcher, Blair, Brown and Blunkett and the rest of 'our' politicians are selling, indeed have sold this country cheap. British craftsmen, engineers and scientists are just as good, and in my opinion, usually far better than the rest of the world. In the meantime, of three mature male friends with degrees, one has taken to crime, one is in a dead end job and I'm fed up begging.
I will soon be doing a third degree, hoping against hope to make myself even more employable, should a better Britain emerge after Bliar and company have sold us out.

________________________________

Always try to improve society rather than just take from it. Until then, lawyer stuff. Copying, duplication or transmission of this material whole or in part is not permitted without the written permission of the author. The contents of this text are for illustrative purposes only. Errors and omissions excepted. Contents subject to change without notice. All material herein is subject to copyright, patent and other intellectual property rights. All rights reserved. Copyright (C) J.Partridge. 2004.
This monograph is stairlift page ver 1h. Nov 2005. http://www.btinternet.com/~jhpart/stairs1b.htm