David Butcher, a California inventor who’s long been on the cutting edge of pedal-power innovation, has come up with a new, original contraption, a pedal-powered hammer.

(As described in The Human-Powered Home and as you can see in the video, David’s pedal-powered prime mover doesn’t use a traditional bike or exercise bike as its foundation. Instead, he builds his own frame and adds a heavy flywheel that helps provide momentum once the operator gets going and evens out the otherwise intermittent forces of pedaling.)