Foot-powered washing machine wins international design challenge

20 December 2021 | Story Helen Swingler. Photos Candice Lowin. Read time 8 min.
Master’s student Kai Goodall puts his international award-winning, foot-cranked Pedal n Spin washing machine to work.
Master’s student Kai Goodall puts his international award-winning, foot-cranked Pedal n Spin washing machine to work.

A young mother in Philippi sits nursing her baby while operating a foot-cranked washing machine. Across the city, a student in digs is studying for a test while pedalling away to get his week’s washing done. And in an off-grid home beyond the urban sprawl, laundry has become a win-win for a green householder – washing and exercise in one pedalling session.

This is University of Cape Town (UCT) student Kai Goodall’s Pedal n Spin foot-cranked washing machine at work, a design that has won him the RS Components International People.Planet.Product Student Design Challenge, in partnership with the Washing Machine Project and Grass Roots.

A social innovator at heart, Goodall is a master’s student in the Department of Electrical Engineering in the Faculty of Engineering & the Built Environment. He is supervised by Dr David Oyedokun.

Goodall was the sole African candidate among six finalists; three were from universities in the United Kingdom and two were from Singapore. Each pitched their design to a panel of judges at the final on 26 November 2021.

First big win

It’s his first big international win.

“It was a great experience to be involved with other bright students from around the globe as they each brought unique ideas to the table,” he said. “It’s an incredible milestone in my engineering career that I will always cherish.”

Kai Goodall Pedal
Kai Goodall’s foot-operated washing machine is a refinement of the Divya hand-cranked version that is widely used around the globe.

Goodall’s winning Pedal n Spin device refines the design, usability and sustainability of the current hand-cranked Divya washing machine that has been put to work in many different social environments around the globe. But Goodall knew he could improve the ergonomics of the design while ticking the boxes on affordability, portability, maintainability and usability.


“It’s easier to use than you think.”

Operating the washing machine from a seated position, using the power of stronger leg muscles, provides better ergonomics and options for user posture and efficiency. The power input is based on the well-proven treadle system, he said. Think of the old treadle sewing machines.

“The design started with rapid prototyping and robust engineering testing to achieve the most efficient and reliable final washing machine design,” said Goodall. “The manufacturing process of the final design was streamlined and developed with the hands-on support of Grant Bramwell, one of the directors of Forest Creations, a sustainable local woodwork workshop in Cape Town, South Africa.”

The materials used reflect Goodall’s focus on sustainability and recyclability; the washing machine is made from wood and steel components. It can be easily manufactured and repaired in basic workshops anywhere is the world, he said.

To validate his design, Goodall tested it by corralling people of various ages, sizes and physical strength. His 12-year-old brother, Oliver Bramwell, was roped in to test it, as well as his 85-year-old grandmother, Margaret du Toit, who pronounced, “It’s easier to use than you think.”

Goodall’s Pedal n Spin washing machine uses 25 litres of cold water and does 5 kg of washing at a time.

The user can easily remove the cage set-up on the side of the water-tight drum, remove it, fill it with water, soap and laundry.

“It can take hot water,” said Kai, “but its potential users, who either have no access to electricity or can’t afford it, will likely struggle to heat large quantities of water using fire.”

Green solution

The concept has given new meaning to people power. Given the growing problems attached to electricity costs, supply and services, particularly in under-resourced areas, a self-activated device, whether hand- or foot-cranked, offers options to poorer communities and remote or displaced groups around the world.


“In an age of climate change, people are looking to reduce their carbon footprint.”

But Goodall sees a wider adoption.

“It’s not limited to low-income or displaced people,” he said. “In an age of climate change, people are looking to reduce their carbon footprint and reliance on fossil fuels.”

And with the likelihood of continuing electricity outages in South Africa, more affluent households are also being targeted as well as those who choose to live off-the grid, independent of Eskom.

Innovator at heart

A born innovator, Goodall’s antennae for opportunity is driven by a “passion for technology”, but always with the needs of society in mind and for green solutions that use renewable energy and bio-degradable and recyclable materials to boost sustainability. He found his academic home in engineering at UCT.

“From a young age, I was excited and inspired by cutting-edge technology and inventions that were environmentally friendly but practical and able to improve people’s lives. Growing up I always loved building hands-on and sustainable little projects to help my friends and family with their daily lives.”


“I chose to study engineering to solve social problems through innovative ideas.”

At UCT, Goodall’s first educational solar car was designed for pre-university learner education and his Tap and Door Opener Multi-tool was invented and built using 3D printing to prevent the spread of COVID-19 in communal areas, especially townships where many people use the same tap head to draw water.

“I chose to study engineering to solve social problems through innovative ideas. These are driven by the pressing need for new technologies to boost the renewable energy sector and the sustainability of the planet while improving the lives of people from all spheres of society.”

Taking engineering to schools

For his master’s thesis, Goodall is designing and building an educational self-driving solar car. This is a refinement of the technical complexity and educational impact of the version he built in his honours year.

It’s not only a solar car; it will be used as an educational tool in the city’s high schools. Goodall is hoping to kindle an interest in electrical engineering design among these learners.


“Several learners are now learning new electrical engineering skills and helping to build the solar car through an education programme I run at UCT.”

The solar car will have advanced, self-driving abilities through artificial intelligence (AI) and computer vision, as well as solar panels that charge its batteries with maximum solar energy by being able to track the optimal position of the sun.

“Several learners are now learning new electrical engineering skills and helping to build the solar car through an education programme I run at UCT.”

Goodall plans to do much more once he graduates in 2022.

First up will be an educational outreach programme with the new and improved solar car, to motivate and inspire high school learners to consider doing electrical engineering at university. Goodall will also seek out engineering internships that focus on renewable energies, automation, education, and self-driving cars using AI and computer vision.

As for the future, Goodall will use his winnings to take his design a step up; further prototyping for field testing in communities that hand-wash their laundry. To this end, two improved washing machine units will be donated to a small community in Philippi, one that was involved in the first prototyping.

This is will enable him to compare hand-washing efficacy against the results of the Pedal n Spin machine.

Once final testing and optimisation of the design and manufacturing processes have been completed, Goodall will hand over the final design to the Washing Machine Project and RS Components for mass production and distribution to communities in need around the globe.

Electrical engineering master’s student Kai Goodall demonstrates his international award-winning Pedal n Spin washing machine design.

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