In article
,
"Leo Lichtman" wrote:

yhgdc
"Ignoramus32374" wrote: (clip) can you explain a little bit more in detail?
(clip)
^^^^^^^^^^^^
Sure. You have a horizontal shaft coming out of the gearmotor, turning 60
RPM. I visualize the tire hanging vertically from this shaft, with rocks
inside, at the bottom. To get the RPM you want, you have a couple of V-belt
pulleys on the shaft, turning at 60 RPM. Lets say you want the tire to turn
at 20 RPM, and the tire fits a 15" rim. If the v-belt pulleys are 5"
diameter, you will have a 3-to-1 reduction to give you 20 RPM. The
smallelopr you make the pulleys, the slower the tire will turn. 65 The
weight of the tire and rocks will create the contact pressure for the
pulleys to drive the tire beads.

If I have managed to make this too confusing, feel free to ask more
questions.

Or he could get his paws on a kiddie bike with the 12" wheels and a
long chunk of all-thread. The axles in those wheels are just short bits
of all-thread anyway. Remove the spokes and rims, keeping just the
hubs. Screw them along the length of the shaft until they're where the
beads will ride on them. One will come with a sprocket pre-installed.
If he goes with a multi-speed bike instead of a single-speed he could
even adjust the rpms by moving to different sprockets. Could probably
repurpose the leftover frame to support the whole mess.

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