Mike writes –

An inertia friction welder powered by a bicycle. Built in 2 months and at a cost of £302. Finished and run for the first time at around 6pm GMT, Saturday 15th December. Thanks go to Andy for the welding, Steevo for the machining, Martin for grafting, Greg for filming and squeaking, Graeme for his yard and cups of tea, JCB for the use of their workshop and Bolton Steam Museum for the flywheel.

A bicycle-powered welder – [via] Link.