Here are two videos from Specialized and Google's competition, Innovate or Die, that feature bicycle pedal-powered projects. One video is from Mike, who is part of a team that inertia welds two pieces of aluminum by pedaling a stationary bike. The bike is attached to a 150 kilogram flywheel, which is then attached to motorcycle chain, which is connected to a pre-WW II lathe. The weld is "slightly out of tolerance," but the two pieces of aluminum are in fact joined. Check out this First YouTube video. (Technical and energy specs for the machine after the jump.)
The other video is of Daniel who pedals his bike to the tennis court with a "bike trailer" that is a pedal-powered tennis ball launcher. To make the tennis ball launcher, he used a leaking 5 gallon water jug and recycled some old bikes and components. Check out this Second YouTube video. (Of course, this begs the question, what else might some cyclists with creative imaginations and more time on their hands than sense launch with a similar type of machine?)
Image lifted from the YouTube videos by Wheelgirl. Pedal-powered inertia welding via bicyledesign to ecofriend. Pedal-powered tennis ball launcher via danielbauen to makezine .
According to bicycledesign, here are the specs on the inertia welder rig:
"Flywheel weight - approx 150 kg
Gear ratio to flywheel - 5.79:1
Gear ratio flywheel to work piece - 37:19
Flywheel energy - 30 Kilojoules @ 500 rpm (I think we only managed around 400-450 rpm though)"
