This is my most recent push stick for inline skating. It works OK but
it is still being improved.

http://farm9.staticflickr.com/8524/8...3e921320_z.jpg

In the bottom right, there is a yellow gearbox.

Between that gearbox and the crankshaft inside of the orange body,
there is a 1/4 inch aluminum rod connecting the two.

Being a two cycle engine, there is some sputtering. The wheel bounces
back and forth as it turns and the gears get banged around a lot. I'm
afraid that's going to eventually break stuff.

The 1/4 inch aluminum drive rod is about 8 inches long. I would like
to replace it with something flexible, or put a clutch in there.
Anything that would absorb some shock. I suppose a clutch would have
to be at the gearbox output, since the motor spins the rod at
thousands of RPMs.

Any easy possibilities?

How about a smaller diameter 8 inch rod of spring steel? I don't know
if spring steel works that way, just asking.

Or perhaps the amount of stress when it's banging around at idle is
no greater than the more uniform stress when it's pushing me up a
hill. I could just wait and repair it as needed. I'm definitely going
to continue testing it as is.

Thanks.