The Human Powered Ferris Wheel Project
I conceived this idea after witnessing a much simpler two-rider version at the Cyclecide Bike Rodeo in the autumn of 2003, hosted at The Pound SF.
Cyclecide's version seemed like a good idea that could be vastly improved, and over the next 6 months I developed my idea of a larger, hexagonally shaped, six person device into a set of plans that could actually work. I started fabrication in early June 2004 and completed on the evening of Sept. 11th, the night before I was to leave for Burningman 2004. It was the first time I would attempt to construct it and I had no idea if I would even be able to set it up or how I would operate the thing. The Gods of invention smiled upon me and it performed admirably for the whole festival. There were some hazardous learning experiences along the way; a falling pipe narrowly missed braining me and two components were bent by too much undistributed weight. The most important lesson I learned was to respect simultaneously the scale and the limitations of my work. I also became a much better welder and metalworker due to spending approximately 200 hours in the shop.
The wheel is indirectly powered by the leg strength of its passengers; unlike standard carnival rides there is no direct torque applied to the central axle. As a rider pedals, the chair is rocked slightly forward, changing the center of gravity of the whole wheel. The wheel then rotates forward just enough to "correct" the imbalance. As the rider continues to apply force to the pedals the chair continues to rock forward slightly, and the Wheel continues to rotate. This effect has maximums at the top and bottom positions of the wheel's rotation. With six riders pedaling at once, the acceleration is quite rapid and the Wheel quickly reaches its effective maximum speed of about 9 RPM, determined wholly by the strength of the riders, gravity, and frictional losses.
I have considered attaching a generator to the main axle and using it to power lights on the wheel, so that the faster the riders pedal the more lights turn on. Another improvement would be to incorporate some sort of gear reduction system, since the current design has the riders pedaling very slowly which makes it more difficult for them to control the swing of their chair.
One major problem with this design is the lack of brakes! To get it to stop the "operator" yells at everyone to stop pedaling, and as the wheel slows he and an assistant must grab a chair and hang onto it for dear life, causing that chair and its rider to eventually come to rest at the lowest point. Loading and unloading was a challenge because there was nothing to stop the wheel from rotating abruptly once it was unbalanced.
Click the thumbnails below for more info.