by Mathieu Gonnet, Michka Mélo & numerous other participants from SummerLab @ Nantes

inspired by Paul Granjon's Oriel Factory project

We built a dynamo out of a printer DC motor we removed from a dead printer. We built the crank and chassis out of reclaimed wood, foam & cardboard we found in the architecture school dumpster.

DC motors are nice because they are reversible. When you give them current, they turn around, and when you make them turn around, they give you current. In printers, you can also find steppers (moteurs pas à pas) which are recognizable by the fact that they have four connectors instead of two. It is also better to check if your motor is AC or DC before starting building the system.

In terms of performance, the highest voltage we obtained was 12 V, when cranking at max possible speed with our arms. We will test it later in the week with an incandescent lamp.

We started to build the system with very little tools - a swiss knife - and had quite a lot of difficulties. On the second day, we used more advanced tools - electric saw, drill- and could make a working design. The most tricky making task was to make an efficient and stable connection between the two wheels, and this was the reason why we used more advanced tools - outside of comfort issues.

We connected the crank to a bigger wheel to have a demultiplcation effect. We thought about two designs, one with direct contact between the bigger wheel and the motor, and another with a drive belt between the two. The first design needed a perfect wheel and a good chassis, which was difficult to built by non-specialists like us. We therefore moved to the second design.

It was very interesting how a lot of people from the lab came around to give us hints. It was a real Research & Develop It Together experiment !