[TheForge] Dumpster Find

Thu Jul 31 23:08:02 2003

Wow Charles,
Many thanks for the details on the grinding wheel/exercycle.  I really like
the 'off the grid' aspect of the whole thing. This would be great at
blacksmithing demos!  Do you have any other cool 'off the grid' ideas to
share that use dumpster-castoff?

-Alix
Voodoo Moon Forge

-----Original Message-----
From: [email protected]
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Sent: Thursday, July 31, 2003 7:16 PM
To: [email protected]
Subject: Re: [TheForge] Dumpster Find

Most of the excercycles have a large diameter flywheel with a small
sprocket for #35 chain (standard Bicycle size).   The sprag clutch
engages in only one direction, much like the hub of a bicycle.  The
outside of the flywheel is flat or generally slightly crowned.    You
mount the flywheel on a column( generally this requires a fork to be
fabricated to support both sides).   You wrap a short section of  #35
chain around the top of the sprocket with a door spring attached to the
backside of the chain on one end, and the base of the column on the
other.   Now you make a lever hinged to the front of the column under
the sprocket and attach one of the old pedals to it.  Attach the free
end of the #35 chain  to the lever.   Now you can stand in front of the
column and pump on the lever and it will bring the wheel up to speed, as
the chain saws back and forth across the top of the sprocket.    When it
slows down, give it a couple of pumps.

   As for the grinding wheel, I mount an arbor or polishing head to the
top of the column.  Generally they will have a 1/2" shaft with a v-belt
sheave and a couple of spacers all held on with socket head cap screws.
I remove the sheave, and then run a flat belt around the outside of the
flywheel and around the 1/2" shaft directly.  It will really spin up
fast.   You can mount up to a six inch buffing and grinding wheels to
it. The real concern is it is easy to overspeed the wheels with no
load.  A real slick unit for off the grid.  I made one years ago for my
dad to use in his barn, and another later for a woodworking friend,
although for him I  set it up as a small woodworking lathe.

    The old style grinding wheels used the size of the stone to achieve
both the  surface speed required, as well as  the kinetic energy
required, this approach uses the mass of the flywheel and the ratio of
the shafts.   It is a versatile power source, and could be as easily
used to power a blower, which is why I don't mind having a couple of the
wheels around.  They are relatively easy to come by at garage sales and
on the heap, while high torque dc gearmotors with freewheeling neutral
levers are not ( and these make good machine feeds) which is why I went
for the motors.

Charles

Alix Peshette wrote:

>Hi Charles,
>Wanna share how you made an exercycle into a grinding wheel?  I see those
>exercycles at so many yard sales.
>
>-Alix
>Voodoo Moon Forge
>
>
>
>

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