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HAND-POWERED

WASHING MACHINE

D'kar, Botswana

PROJECT DESCRIPTION

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Washing clothes is a difficult and time-consuming task in a village where most homes lack electricity and even running water. Women spend hours each week washing their family’s clothes, and often carry large buckets of water to their homes from a community tap over a kilometer away.

A manually powered washing machine located at the D’kar Innovation Center would provide a more efficient way for women to wash their clothes, as well as provide a small amount of income to the Center if the machine is operated like a laundromat.  

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PROJECT GOALS

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Analyze the current state of the project and decide what is feasible to achieve in the short time we have to work.

  • The machine was tested briefly previously, but had not been used since.

    • Goal: Conduct user tests to identify issues and strengths.

    • Result: Brief user testing of the pre-existing design was conducted, identifying issues like the machine’s handle being rough and the barrel not spinning.

  • The inner barrel was not connected to the outside mechanism, meaning the machine was inoperable.

    • Goal: Connect the barrel and the drive mechanism to make the machine functional.

    • Result: Welded the wheel onto the barrel’s axle to permanently join them.

  • The outside mechanism consisted of a rigid bolt as a handle.

    • Goal: Rework user operation mechanism - a quick test showed the existing handle would cause injury or pain over long periods of use.

    • Result: Went through several iterations of handles before deciding to switch user operation mode altogether, to a pair of handles attached to rope. This design also underwent testing and several versions.

  • No information existed about how much soap and water to use.

    • Goal: Determine standard amounts of soap and water to use, as well as time needed to clean clothes.

    • Result: Determined the necessary amounts and times.

PROJECT SUMMARY

We first tested the machine ourselves to identify the basic issues with the design. When we arrived, the machine’s inner barrel was free-spinning, and turning the bicycle wheel did not spin the barrel. We fixed this by welding the bicycle wheel to the axle attached to the inner barrel. We then tested the machine by filling it with water and soap and washing a small load of clothes. The handle that was attached to the wheel was rigid and caused pain to the user, so we added a PVC handle for comfort and ease of use.

After further testing, we decided that the existing crank mechanism was not user-friendly or ergonomic, and it was physically quite difficult to use when the machine was full of clothes. We noted that in the original project report, the team mentioned using strings attached to the bicycle wheel to rock the barrel back and forth. We tested this mechanism with some thin string and handles made from PVC. This mechanism was much preferred by the community members we had test the machine. We then improved upon this design with more carefully installed, thicker rope for durability and comfort.

Over the course of the week, we washed many loads of clothes to determine the time and amount of water and soap needed for a good wash. We determined that the machine needs two handfuls of hand wash detergent and two large buckets of water for the wash cycle. The machine should be operated for 10 to 20 minutes to clean the clothes, depending on how dirty they are. Then the machine should be drained, and two more buckets of water should be added for the rinse cycle. The rinse cycle should last around 5 minutes.

We also added a few small changes. We added a mesh screen to the top of the filter to prevent large debris from flowing in with the water. We also painted a rusty patch in the machine’s inner barrel. Finally, we added a hook to hold the handles off the ground when not in use.

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