The lathe was powered by an old 1 HP Craftsman motor run through a jackshaft and a 4 step pulley, the
speed was somewhat variable. I had read about people adapting treadmill motors to lathes and decided
to attempt it. The first free treadmill was not operating because the controller was bad, but had a $300-
according to the owner- motor, the second had no controller and the third had a controller I could not
adapt. I bought a rebuilt MC-60 controller for $50.00 and my core and started down the slippery slope.
I could not find a V-belt pulley to replace the serpentine belt pulley, so I took the pulley off a second DC
motor and bored it out to 3/4” to fit on the jackshaft I used with my old motor.
The motor had a 16mm (.6295In) shaft with the pulley/flywheel held on by a 1/2” 13tpi left hand thread.
The cross slide rest is one reason I want to keep this old lathe, I can do light machine work with it as well
as wood turning. A local machine shop broached a 3/16” keyway in the pulley for $15.00 and I was ready
to start assembly.
The only problem is the V belt drive is on the left side of mounting setup so the drive motor has to set on
the left side. I would have to make the mounting plate extra wide or reverse the DC motor. Wanting to
save space I decided to reverse the DC motor by switching the motor leads, but the left hand mounted
pulley would want to spin off, so I drilled a hole, half in the drive shaft and half in the pulley and threaded
it 1/4-20, inserting a 1/4-20 set screw with blue lock tight eliminated the problem of the pulley coming off.
I now have the motor mounted to the special adapter plate and driving a serpentine pulley that will turn
the jack shaft that will turn my lathe. The plate is fastened to a sturdy piano hinge that will allow the
weight of the motor and drive assembly to provide tension on the V-belt. The DC motor had a tensionilng
bracket that I used to tension the serpentine belt.
The controller might not be damaged by wood chips and dust, but I decided to enclose it in its own box.
I made the back from sheet metal, but wanted to be able to see the lights on the controller so the front
is plexiglass. The controller sets behind the head of the lathe. I wanted to use a regular electronic box
to mount the controls for the lathe, but Radio Shack closed its store in Missoula last month, so I adapted
a double gang electric box.!
The fuse is from the original treadmill, and is a 12 amp ceramic fuse. the red light and the potentiometer
for adjusting the speed also came from the treadmill. I used a heavy duty toggle switch from my supply.
here is the drive unit in place.
Looking at it, it is a little Rube Goldberg, but it does work. The electric power comes through an outlet
on the lathe that is controlled by a special paddle switch that I can shut off by bumping it with my leg
just in case I get careless and need an emergency shut off. It works good so far and my only problem
is that I just got another free DC motor that has a keyed shaft that is 17mm (.6693in). If I redo my
adapter plate, I could build a V-belt pulley that would fit on that motor and mount it directly below
lathe head. That is for another day. I want to thank Rick M. / Woodknack and Sawdustonmyshoulders
for the help and pictures that made this project a lot easier.
The DC motor is rated at 21.5 Amp and 2.65 peak HP, but the AC fuse is 12 amp so I am getting a
lot more power at a lower cost thanks to that electronic control box. There may just be a few more
DC motor projects in my future.
-- As ever, Gus-the 78 yr young apprentice carpenter