INTRO & BACKGROUND¶

I’ve been meaning for almost ten years now to build a pedal powered washing machine but never got round to it. However I’m ready to crack on with it now I’ve got workshop space and power tools. Since I’ve mentioned this to people some have said they think it’s a crazy and pointless idea which can’t work. Well, I know it can work and have seen it done and seen that it worked well. Considering how time consuming hand washing is, I don’t think 20 minutes cycling is an unreasonable amount of effort for washing a load of clothes.

The reason pedal powered washing machines do make sense is that the actual mechanical power required is well within the capability of a human to produce. It makes sense as long as you don’t try to heat the water with pedal power or waste energy by converting kinetic energy into electricity and back using the existing electric motor/heater. Some people have tried this approach (http://www.los-gatos.ca.us/davidbu/pedgen/washing_machine.html) but it’s not a sensible way to do it.

I’ve met people in the UK who have tried and failed to build direct drive pedal powered washing machines. They failed because the drum in the UK’s front loaded washing machines vibrates massively as the uneven load rotates inside. They had simply run a belt from the back wheel of a bike to the pulley on the washing machine but inevitably it would keep coming right off. You need little more complicate engineering to successfully use these front loaders for pedal power.

On other types of washing machine, far more common in the rest of europe, the drum is supported front and back and does not shake about so much. The device is top loaded with a hatch in the drum. Using these machines as a starting point it is much easier to achieve direct drive and the details of quite a few can be found online. www.designboom.com/weblog/cat/8/view/11... http://www.outils-autonomie.info/index.php?option=com_content&view=article&id=1:lave-linge-a-pedales&catid=1:fiches-techniques&Itemid=2 www.homelessdave.com/hdwashingman.htm.

Interestingly, the same basic design is generally arrived at by people who have built pedal powered washing machines which are not based on existing washing machines. Check out the Bicilavadora designed by MIT students web.mit.edu/teresab/www/Bicilavadora/in... and MayaPedal www.mayapedal.org http://www.youtube.com/watch?v=Le85KjalzwM. A variation on the theme spins the drum while the bike is actually on the road! gadgether.com/bicycle-powered-washing-m...

In the USA they also mostly use top loaded washing machines but with a vertical axis of rotation. These have also be successfully converted to pedal power… www.homelessdave.com/hdwashingman.htm http://www.dailymotion.com/video/xb3dzv_how-to-wash-clothes-with-a-bicycle_school

CURRENT INSPIRATION¶

I’ll be working to the design of Alex Gadsden which starts with a standard front loading horizontal axis washing machine. The key to his design is the use of two universal joints and a prop shaft to keep the unwanted movement of the drum separate from the drive belt. You can view it in use in this film which I made a back in 2005 www.youtube.com/watch?v=kQ8__8Gidig

Alex has a website about his prototype (http://www.cyclean.biz/mainmenu.html) but sadly it has not been updated in years and no designs or decent photos have been added. However, in the forum section, Alex did post a brief summary of how to go about building one…

“…try getting hold of a car wheel, universal joint, or back axel & a long belt to drive the car wheel off the bike wheel. If you use the car wheel it will act as a flywheel too; just to make life easier.”

“A 21 gear bike is best as you will get a good spin cycle. Build a frame for the bike to sit on using the brazons (mud gard fixing holes). It needs to be a nice snug fit so measure twice, cut once!”

“Now look at the height of the drive shaft out of the back of the washing machine, connect your UJ to the drive shaft on the washing machine, connect the car wheel to the UJ and fix the wheel to the bike frame. Now place the drive belt around the car wheel and bike wheel. Add a belt tensioner, if required!”

It’s not much to go on but I think I remember and understand the construction well so no mater. I notice his write up (see it in full here) differs from his prototype in recommending the use of a car wheel and also in filling the structure with concrete. I don’t like the idea of a car wheel and think it would not work well as a fly wheel as he proposes. However a flywheel would improve the users experience so it might be worth considering a concrete rear wheel for the bike.

MY DESIGN BRIEF¶

As always when I attempt to design and build something, I am aim for something that can be reproduced by others. I want to avoid having to manufacture parts if possible (for example the home made UJs used in Alex’s prototype, but also avoid having to purchase new components where possible. If new parts must be purchased then they should be cheap and easily obtained. Ideally, everything used will be reclaimed materials but again, they should be easily obtained, not a one off lucky find that nobody else will be able to get hold of.

I want it to be relatively portable so that it can be taken to events like climate camp to provide communal laundry facilities so that means it can’t be filled with concrete or have parts that require bolting to the floor. Might want to consider fitting little wheels to make it easier to move, and perhaps also removed the concrete block and instead use a water filled weight system.

I also want it to be heath and safety conscious so that peoples fingers or clothes are less likely to get caught up in moving parts. On the other hand, I want the way it works to be visible so moving parts should ideally be behind plexiglass.

CONSTRUCTION CONSIDERATIONS¶

The required rotation speeds during the wash cycle are not especially high. The aim is to agitate the fibers in the cloths and work the water fully into and through the fabric. This is done by tumbling the clothes within the drum and if the speed was too high the clothes would remain static pressed against the side of the drum by centrifugal forces. On the other hand, this is exactly what’s needed during the spin cycle in order to drive out the water. Spin cycles of 600/800 rpm are typical for the crappy inefficient machines sold in the USA but they don’t do a good job of getting the water out of the clothes. Top end machines sold in Europe spin at up to 2,000 RPM. In the UK, typical spin speeds are 1,000 or 1,200 RPM.

A cyclist typically cranks the pedals at about 50 to 100 RPM. The highest gearing ratio on a typical bike is about 3:1 (eg. 52 teeth to 14 teeth). If we want spin speeds of 1,000 rpm then we’ll require the final gearing ratio be closer to 20:1. We’ll achieve that by using the back wheel of the bike as a massive pulley (26 or 27 inchs in diameter). We’ll then use a large fan belt to drive a smaller pulley which will be connected to the drum via the two universal joints. If our final pulley is 3 inchs in diameter then the wheel to pulley ratio is about 9:1 and the total gearing about 27:1! A larger pulley would make more sense, perhaps closer to 5" for a final ration of about 15:1

PLANNED OPERATION¶

In operation, the user will place a load of clothes in the drum and close the door. They may have chosen to place the washing detergent in with the clothes in one of those open ball things or they can add it to the wash water. They should avoid using too much to ensure that the limited amount of rinse water will be enough to remove the residues.

The user now fetches the wash water which may have been preheated somewhere else, perhaps on a wood fired boiler. Before adding the water the user must ensure that the valve used for letting out waste water is firmly closed. The user can now add the water, and the detergent if that’s not already been done.

As the water drains into the drum the user mounts the bicycle and starts pedaling. The bike should have been left in a low gear. The user continues to pedal after all the water has entered the tank. It may be a good idea to occasionally stop, pause, then restart so that the clothes are better agitated and separated.

If we imagine a full wash cycle to be about 20 minutes then the user should pedal at a fairly leisurely pace for about 10 minutes and then dismount to open the drain valve. This is a good opportunity to take a piss break or fetch a cup of coffee etc. There is little to be gained by continuing to pedal while the water drains.

When the water has drained the user can hop back on and get the drum spinning fast for a short while to drive out the last of the dirty soapy water. Now the user closes the waste valve fully and lets in the rinse water. Again, the user remounts and starts pedaling again just like with the wash cycle.

After about 5 minutes the user dismounts and opens the drain valve but this time takes no break. Cycling should continue to complete the rinse and the pace should increase massively when the drum is fully emptied. This sprint stage will force out the remaining water and should be done as fast as possible. The user will step up through the gears until the drum is operating at the fastest possible revolutions. The longer this can be maintained, the drier the clothes will be when removed from the machine. Lets aim at about three minutes which would bring the entire process up to about 20 minutes.

Before dismounting the user should return the bike to a low gear. The drain valve should also be closed before taking the clothes to hang up.

PARTS OBTAINED & SOUGHT¶

The Washing Machine¶

Washing machines are easy to obtain (assume you have transport). It is not uncommon to see them dumped outside blocks of flats and you can always get them from freecycle. I have a faulty front load washing machine donated by a nearby squat. It had a rat chewed wiring loom and a burnt out program timer and I failed. It’s fine for what we need – the bearing are good and the drum and door seals do not leak.

Drive mechanism and gearing¶

I’ve obtained two universal joints from scraped cars which would otherwise be hard to make (en.wikipedia.org/wiki/Universal_joint). Unfortunately one of these seems a bit ‘lumpy’ but it is all I have an might improve in use. I’ll try to avoid welding it on so that it can be swapped with a better one in future. They can be found in the steering column of most cars. Other sources include socket sets.

We’ll also need a large drive belt and pulley wheel. Alex used a wheel barrow wheel but recommends a car wheel in his forum post. The important thing here is that the pulley wheel has to be fixed to an axle which pass through bearings of some kind. I predict this to be one of the hardest parts to sort out. The drive belt can be made from rubber hose pipe although making a flexible join will be a challenge.

The Bike & Stand¶

I’ve not yet got hold of a bike to become the power unit but these are pretty easy to obtain. It could be a broken bike, perhaps with bent front forks etc. It doesn’t need brakes, front wheel or back tire but it will need working gears and adjustable seat height. Ideally it will be a racer type bike with 27 inch wheel. A womens frame would be good as it is obviously easier for people to get on and off. I’ll ask at 56a and rAtstars bike workshop. I guess an advert on freecycle would also be a way to obtain a suitable bike.

The bike stand could be metal or timber. I’ll probably use metal as I have some dexion angle iron and a welding kit.

Water tanks¶

For the water tank I was thinking about having two, one for wash cycle and another for rinse. The wash cycle one could be filled with warm water preheated somewhere else. It could also have the detergent added to it if need be. Likewise, the rinse bottle could have white vinegar added to soften the clothes in areas of hard water.

Originally I was thinking about using 25 liter water carriers which can be freely obtained (detergent filled ones are used and thrown out by restaurants and other business). However, I happen to have two of the slightly smaller 18.5 liter bottles as used on office water coolers so I think I’ll use those. There is an argument for using metal rather than plastic containers as these could be heated up on a fire etc. The 20 litre veg oil drums might be worth considering, they are very easy to get hold of.

I’ve not yet considered the need for a waste tank. I have a low profile fuel tank I could use but I paid quite a bit for it an would prefer a cheaper and more reproducible solution. Depending on the installation, it is entirely possible that no waste tank will be needed. The waste water could be piped into some kind of grey water filtering system or straight down the drain.

CONSTRUCTION PROGRESS UPDATES¶

First steps¶

I’ve been hunting out the parts needed (see above) and started work with what I have by stripping down the washing machine. I’ve removed the wiring loom and all electronics, the solenoids and detergent drawer, drive motor and belt, waste pump and pipes etc. What’s left is the structure itself with the door, the inner and outer drum, concrete weight, springs and suspension arms plus the rubber inlet and outlet pipes. I’ve left the heating element in the drum simply to retain the waterproof seal, likewise for some kind of water level sensor that’s attached to a thin rubber hose placed above the drum.

I’ve started looking at how to connect to the rubber inlet and outlet pipes. I have found that I can make an adequate join to a piece of PVC plumbing pipe which is a promising start. I’ve also been considering what I want to do about valves to let the water in and out. Alex used off-the-shelf but expensive stop cocks but I think I’ll take a much cheaper approach involving bicycle inner tubes.

Construction starts¶

I’ve cut up some 3/4" mild steel rod in order to make the drive shaft. I needed to grind down the ends a little to make them fit into the universal joints. I first made a short stub axle which I welded to face of the bolt in the centre of the pulley on the back of the drum. I didn’t get it perfectly centred but the beauty of using the universal joints is that I didn’t actually have to be exact. I then cut another length of rod, this time about 12" and fitted this to the other end of the universal joint attached to the first stub axle.

Sadly my second UJ is pretty fucked and I’m now sure I will need to replace it. However I don’t want to let that put a hold on progress so I’ve fitted it anyway. So, currently I have a short stub axle welded to the back of the drum, then a CJ and another 12 inches of prop shaft and then another CJ. Next step would be another shortish length of propshaft through some bearings and fitted with a pulley – but I don’t currently have the pulley or the bearings.

Stuck for parts?¶

Still no project bike so I laid a few bits of angle iron on the floor with another bike to give me inspiration. It didn’t help, can’t really build a frame without the actual bike I intend to use. I dropped round to 56a but they don’t have anything.

Meanwhile, I’ve been wondering what the hell I could use for the pulley at the bike end of the drive shaft. It needs to have bearings and be pretty robust. Alex used a wheelbarrow wheel and it’s axle (which probably didn’t have rear bearings, I know the one here doesn’t) but I don’t want to canabalise a perfectly good barrow. I thought I had nothing suitable but perhaps I do…

I looked at the motor I had removed from the washing machine. It has a shaft supported by bearings and it is pretty robust. Sure it has loads of crap I don’t need that is in the way of the shaft but ten minutes of work with an angle grinder changed all that. What I now have is the shaft, the bearings and the bits of the motor housing that support the bearings. The shaft still has the motor rotor windings etc. but the outside stuff has been removed. It looks like the rotor could be used as-is to provide the pulley although it might be a little small at about 3 inchs in diameter. I think that if the belt showed a tendency to creep off the edge then I could weld on guides. There should be plenty of friction. It looks promising.

Also promising is progress on the plumbing. Using a short piece of PVC waste pipe, I’ve managed to fit a length of bicycle inner tube to the waste outlet of the drum. This tube exits the washing machine at the front where the filter access used to be. Currently the tube is tied up above the level of the drum to prevent drainage or laid down at floor level to enable draining.

No progress¶

Still not obtained a bike so been working on other stuff, making bike trailers. In the process of cutting up a couple of small childens bikes for parts I decided I’d put aside a bottom bracket as an alternative to the dissembled motor shaft. The crank shaft in the bottom bracket is robust and held with two sets of bearings so it’s pretty ideal. I’d just have to find a suitable pulley to fit to the shaft. I might consider using a wheel off one of the kids bikes although they may be a little bigger that I would like, perhaps 9" diameter, and difficult to attach to the axle.

Rolling on¶

I’ve finally got hold of a bike, it’s a Aluminum hybrid from Gian. It’s possibly too good for this particular project but it’s a step-through frame with 27" wheels just as I wanted and I’m fed up with waiting for something else.

The next step is to make the stand which will hold the back wheel off the ground, position the smaller pulley and attach the whole thing to the washing machine. Unfortunately I used some of the materials I had intended to use on making bike trailers so I may now not have enough. Nether-the-less I have made a start with a stand to hold the front wheel/fork and attachments that bolt to the brazen-on which will be what I use for the rear stand.

I’ve decided I will use the little wheel off the kids bike as the smaller pulley. I’ve removed the axle (which had no bearings, just a plastic sleeve) and found I can make it fit onto the crank shaft in the bottom bracket. I’ve fixed it in place by welding it directly to the shaft and it is ready to roll.

Belt and braces¶

Wicked. I picked up a load of worn out 700mm bike tires and cut off the side walls. My plan was to make a drive belt by somehow joining two together but luckily I didn’t need to work out how. As it happens, once you cut away the side walls the tire stretches. Hopefully I fitted the belt and yes, even with my somewhat larger than originally hoped for childrens bike wheel as a small pulley, it fitted.

I’ve not tried it yet and hope it works better than it did when I tried using a bike inner-tube. This seemed promising at the time but would always ride up and off the wheel rims.

Anyway, now I am ready to build the bracing to hold the bottom bracket / drive shaft arrangement and the bike. I’ve already built simple bracing to hold the bike vertical, one set replacing the front wheel and the other bolted to the brazen-on holes just above the rear axle.

UPDATE: The tire drive belt works fine. Tested it at speed and it didn’t come off the rim once! Nice. Worth noting that I could have used a 26" or even a 24" wheel along with a belt made from a 28" tire if I had needed an effectively longer belt.