February 18, 2009
MIT Students Create Bicycle-Powered Washing Machine
Many people living in developing countries often lack access to electricity, making something as common as a washing machine a luxury. However, thanks to some MIT students, a new human-powered machine may now be one step closer to reality.
After working four years to develop their concept, students and staff at MIT built the pedal-powered washing machine primarily from bicycle parts and empty barrels. The machine was designed to be easy and inexpensive to manufacture, mostly using parts and tools that are readily available anywhere in the developing world. And since the machines can be made locally, their use can even generate new jobs.
"The home was like an oasis in the slums of Ventanilla," said Lisa Tacoronte, a MIT junior mechanical engineering major who worked on the project.
A previous version of the washing machine, developed by mechanical engineering graduate student Radu Raduta, was awarded first prize in the 2005 MIT IDEAS competition. The win helped generate additional funding for further development, which led Raduta to improve the machine's inner drum design so it could be more easily manufactured and transported.
The machine's outer housing consists of a standard oil drum cut apart and welded back together to make a shorter barrel, since a full 55-gallon barrel is more laundry than any human would be capable of pedaling, according to Gwyndaf Jones, a D-Lab instructor who worked on the earlier version and who led this years Peru field trip.
The inner, rotating drum is made from a set of identical plastic pieces bolted together, which can be taken apart and stored flat for easy transportation. That was the critical part of Raduta's design. The most difficult part to build is the inner drum, because it is submerged in water and full of clothing that can have metal buttons, which abrades the inner walls, Raduta said.
It has to be stiff enough to keep its shape, but if it is bare steel it will rust, he added. The key part of his thesis research was figuring out how to make the drum strong enough, yet inexpensive and easy to ship. His latest version is made from molded plastic panels, and when disassembled it can fit in a suitcase --which is precisely how the students took it to Peru.
The machine's motor consists of a bicycle frame, minus its wheels, with the chain running forward to a gear at the end of the washer drum's shaft. It uses a standard mountain bike gear range, Jones explained, and the highest gear is the spin cycle, while the lowest gear is the wash cycle.
While the test was not a total success -- some water leaked around the edges of the barrel, the basic design was validated. And with a few small changes an updated version should be able to handle the intensive workload. Students will conduct additional tests this spring.
While vital pieces such as the inner drum segments were brought along from MIT, the outer drum and its supporting structure were built on-site.
"We improvised for whatever we didn't have and often learned how from locals like Wilbur and Gennard, two of the older orphanage residents," Tacoronte said.
"For example, we were unable to cut the two sides for the door on the outer drum that were parallel to the curved surface. Wilbur took up a chisel and went at it with a hammer. The door was done in seconds."
Tacoronte said she found the experience very inspiring.
"The more time I spent there and the more amazing people I met, the more passionate and determined I became about finishing the lavadora and making sure it worked, she says. After the first test run, with the high-gear spin cycle successfully eliminating most of the water from the drum," she said.
"The moment they pulled out the merely damp sheets was exhilarating."
Image Caption: Students work on the bicilavadora in Ventanilla, Peru. Credit Gwyndaf Jones
On the Net: