Bicycle-powered Washing Machine

This post is about a bicycle-powered washing machine project that took place at Matandani School in southern Malawi with Standard 7 students in July 2018.

INTRODUCTION

I have been traveling by bicycle for the last 3 years. Apart from amazing, a human on a bicycle is the most efficient way to move from point A to point B among all vehicles and animals.

Now, while traveling in many places, mainly in rural Africa, it’s typical to see a number of houses sharing the same backyard. In a shared backyard in a village called Leganga in Northern Tanzania I was so impressed by the crazy amount of hours women put on laundry every single day.. Families of 7 or 8 or 9, which is not so uncommon in Africa, will have to spend at least 2 hours a day washing clothes. The women at our backyard seemed to do this all day…

It also needs so much energy to hand wash your clothes that any of us living in the privileged side of the world would be really surprised! I am not saying that you had never hand washed something. But it’s a totally different story to wash all of your clothes, sheets, towels, blankets, etc by hand. (Needless to say, without exaggerating, that the majority of adult women in Africa is more or less as strong as I am, if not more… The non-electric world is mostly physical.)

So the idea was a bicycle-powered washing machine. The extreme efficiency of the bicycle combined with the fact that it is cheap and you can find it everywhere made me think that… at least we have to try! Seemed pretty simple as I was picturing it in my mind. The basic question to be answered was how the transmission of energy will take place.

I was thinking friction as the simplest and most economic way to go. I found some Direct Friction Systems

that was a nice idea, but difficult to implement locally because of the strange way the metal pipe attaches to the drum

So, I was thinking (and drawing) how it could work…

and I imagined how an Indirect Friction System could be

I was thinking about Friction Systems as in Malawi people are using bicycles a lot, so it would be convenient for them to ride to the washing machine with their clothes, attach their wheel to the system and ride. However, not all of the families own a bike. So I preferred that we do something with a bicycle installed so nobody is excluded. I checked YouTube and there were already a lot of people doing something similar. There were many different designs, but mainly two energy transmission systems: the friction one and the free-wheel one. The latter was the way to go if we wanted to have the bicycle installed, as it is not only more convenient but also more efficient.

The idea was to do something that is
1. easily made in a village in Africa,
2. it’s not very expensive,
3. it (re-)uses staff from the local markets and
4. the whole installation can be replicable.

DESIGN AND CONSTRUCTION

So we started thinking with Standard 7 students what should be the questions we need to ask the mothers at home in order to design the right product for them. The 5 basic questions we came up with in regard to doing the laundry  were the following:

1. What are the main problems you face?
2. How many times per week?
3. How much time it takes?
4. Where do you get the water from?
5. Where exactly?

The following day we discussed the results and we concluded that a bicycle powered washing machine would be beneficial for the community.

I brought my bicycle into the class and tried to demonstrate the great amount of energy that is generated when cycling. I hopped onto the bike and started cycling while the bike was fixed (the stand was down) and the back wheel was spinning in the air.

We also discussed what materials would be necessary for such a task.. After that, every learner draw a bicycle powered washing machine that should do the job.

Next day myself, mr Macdonald Maloya (the Science teacher), 3 girls and 3 boys from Standard 7 went to the nearest town, Zomba, to find the necessary parts.

We wanted to keep the cost down so we looked for used drums and used bearings. We also tried to find metal parts to construct the internal cylinder (instead of buying a ready made one), we checked the prices of used big plastic drums, we asked the prices of wire, etc. We walked all around the town and every now and then we were discussing to see how we should proceed. The problem was the drum. The ones we could find at Zomba were 220 litres large, made of plastic. The used ones were priced at 17000 kwacha. I thought they were too expensive and also, primarily, very big.

I was afraid that a 220 lt drum would need a lot of water and it would be very difficult to make it go round. We finally bought a metal one. 100 litres at 11000 kwacha. Also, a day later I found a used wire fence that seemed good for the internal cylinder. The following day we brought everything into the classroom.

We observed what we had bought and we watched a video on YouTube of a design that seemed compelling to follow. Later, learners would get up one by one and show to their fellow students where every piece would fit in the final version that was on the blackboard. We wrote down the cost for everything and every student individually worked out the total cost.

Next step was putting everything together.

The Construction Steps

1 . Making the base of the bicycle
2. Cutting and cleaning the drum
3. Cutting the wholes at the sides of the drum
4. Creating the internal wire cylinder (IWC)
5. Welding the pipe with the IWC
6. Welding the bearings at the side of the drum
7. Attaching the free wheel at the pipe
8. Putting everything together

WHAT WENT WRONG

In retrospect, we did a lot of things wrong. It was the first time we were doing something like this and we couldn’t really predict everything. On top of that, while the welders were very talented in using the tools, the mentality was act-first-think-later. Not proactive that is to say. And some things are irreversible, unfortunately.

1. We should have calculated in advance the necessary height for the base of the bicycle. We didn’t do it, so at the end we had to add an extra piece of metal underneath the drum to support the drum on a higher position.

2. We had to opt for a bigger drum. The 100 lt one was not enough. It’s not that 100 lt are not sufficient, but if we could do it again we would choose at least a 150 lt drum to achieve higher scale economies.

3. The 20-tooth free wheel demanded a lot of effort to turn the whole thing around when the drum was loaded with clothes and 40 lt of water. A 13 year-old child was struggling to make it start.

4. The rear “legs” of the bicycle base were distracting the chain path.

5. They were removed and reinstalled, but even the second time they were hindering the cycling move (i.e. back of feet touching the drum)

6. So, the pipe was welded in order to elongate it, but it had to be really straight cause even minor deviations were producing abnormalities and the chain was getting off the free wheel

7. The IWC was put very close to the inner drum walls (at points, less than 1 cm) and if its door was not properly and very tightly closed it touched the drum from the inside

8. To avoid that, the drum’s door was put to close at a bit higher position, which resulted in lots of water and soap coming out in every revolution. We managed to get the IWC’s door tightly closed and the drum’s door was closing properly but even then there was a lot of water coming out.

9. A lot of the wire edges of the IWC were not well trimmed and in result one of my shirts got ripped a little bit.

10. The IWC’s gaps in-between the wires where not sufficiently small and the clothes were coming out.

11. Worst of all, one of the bearings didn’t work properly as either the welder hit it really hard in order to attach it to the drum (the pipe was slightly larger than the hole of the bearing) or, while welding it, high temperature affected the interior. The result was that it was creating a lot of resistance.

CORRECTIONS

1. The faulty bearing was removed and a new bearing was placed. This was pretty demanding as both the drum and the pipe should stay unaffected.

2. We changed the free wheel to a 25-tooth one and the difference was significant!

3. We also added a third bearing in order to avoid the pipe bending (and the subsequent chain coming out). The third bearing was also placed to enhance the overall stability as

4. we removed the part of the pipe that was inside the IWC because clothes were wrapping around it.

5. To further enhance the stability we added two metal pipes connecting the IWC’s side walls.

5. In order for the clothes not to come out of the IWC we added a thin nylon rope in-between the gaps

6. As far as the water leaking is concerned we used the rubber used to seal cars’ windows

THE TOTAL COST

Above you can find the detailed analysis before the corrections. The total cost was 54450 kwacha. Plus 2000 (new bearing), 200 (glue), 600 (nylon rope), 500 (window rubber), 3000 (welding) = 6300.

Total Cost = 60750 kwacha (72 euros, 84 dollars at the time of writing)

RANDOM PHOTOS

AN ADVANCED VERSION

An advanced version would have a drum of 150 lt and a full crankset and rear derailleur in order for the rider to cycle easily independent of the amount of clothes. Also, a longer chain that would allow for the drum to be placed behind the bicycle. In this way you could cycle without your feet hitting the drum and at the same time the pipe wouldn’t need to be long enough to bend.

THANKS

Many thanks for this great opportunity go to Andrew Moraghan for his invitation to come and volunteer at Matandani School. Also to Givemore Chipanga, Principal of the school who trusted me to proceed with my idea. In addition, many thanks to Mary Saenda and Kenneth Kassam for their support throughout. Not to forget Standard 7 teacher Collins Mulipa and Science teacher Macdonald Maloya. Last but not least, many thanks to standard 7 learners for their cooperation and ideas.

And of course, to the welders!

Chiwaula and Biswek

Cleverton

Ahh! Cleverton, the welder who did most of the job at our washing machine, was inspired by the idea and he did his own!!

❤