A foot-powered lathe must somehow convert the downward motion of the turner's foot to rotary motion of the workpiece. The crank and flywheel have been used to do this at least since Leonardo's time. The problem with this system is that power transmission is not linear. The treadle turns the flywheel farther in midstroke than it does at the top and bottom of the stroke—as the treadle descends, it become easier, and then more difficult to push. Thus the system can accept a strong power impulse only in midstroke, while our legs can efficiently apply a heavy, constant push throughout the motion of the treadle.

A freewheel lathe drive can more efficiently harness muscle energy since it can use all the power we can supply during the treadle stroke. It can be built from bicycle parts and inexpensive hardware. Two lathes based on this drive system have been in use for several years in our shop at the Richmond Middle School in Hanover, New Hampshire, and have proven to be sturdy and reliable in a very demanding situation.