[TheForge] Dumpster Find

[theforge@mailman.qth.net]

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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