I,v been doing further work on my motor, I'v fitted a small DC electric motor as a generator, The generator has a pulley about 1/4" dia, and I put a 1 3/4" pulley on the crankshaft, with that it will run a 6volt radio to full power, or quite a number of LEDs, I'v only tryed 3 white LEDS in parallel. This would be good for a demonstration run. Find a low voltage(6V or less), and low speed motor, I had to sort through about half a dozen before I found the right one.
Ian S C