Removing treadmill motor pulley/converting to V sheave

amuller

Active User
Registered
Joined
Nov 3, 2012
Messages
126
I'm finally getting around to using one of my stashed treadmill motors. These all have a combination flywheel/poly vee sheave held on by a 7/16" (looks like) left hand thread on the end of the shaft. Anybody have experience in how to take these off without damaging anything? Given that these are permanent magnet motors and not heavily built, I'm reluctant to clamp hard or bang on anything.

To use this on a drill press or lathe I need an "A" section v belt groove. I think it would be possible to machine such a groove in the existing sheave but it would be too small for good practice. Thinking of boring a solid V belt sheave and shrinking it onto the existing sheave. How have others approached this?
 
most are l.h. thread, i use a large channel locks. Your second choice seams the best, machine off the poly v and shrink fit a v belt pulley on with a lot of green lock tite.
 
I'll be watching this thread to learn. Have two that I want to do up.
Lotsa pictures please!
 
i have a treadmill motor on my lathe and bandsaw, both work great
Now we need some picts and details on how you did them up! :grin:
The box on the lathe looks sharp.
 
Last edited:
One possibility would be to clamp the motor to the bed of a lathe and machine it under it's own power. But, that might unscrew it as most seem to be CW rotation and left hand thread. Face it towards the headstock and run it backwards? Or take the motor apart and clamp the rotor in wooden v blocks, then take the flywheel off with a chain or strap wrench? Then, to machine it properly one is going to need to make a mandrel and turn it between centers, or ... ? Another point: CW rotation is generally right for a drill press but not usually for a bench lathe. And how do you keep it from unscrewing while delivering power "in reverse?" A pin, a key, a cap screw in the end of the shaft? The more I play around with this, the easier it it to see why people often decide there are easier ways to go....
 
I've done several.all I've seen are 1/2 X 13 left hand thread. Except for commercial treadmill motors that are keyed.i use vise grips on back end.channel locks on pulley.comes right off.turn pulley ribs off to fit your v belt pulley.drill and tap for set screw.install your v belt pulley with set screw.if you can find any commercial treadmills on cl free or cheap enough I would grab it..some have 3 phase motors.others have heavy duty dc motors. Good luck with your project
 
I just put a treadmill motor in my lathe. There’s a thread around here about it. I left the flywheel and pulley on. I used the desired sized pulley with a split taper bushing bored out to perfectly fit over the old poly vee pulley. Once cranked down it had a very tight fit and I didn’t have to risk damaging the motor.
 
I will add, I’ve had to build in additional cooling via a 120v computer fan to cool the motor as it has no internal/external cooling fan.
 
the 1 i used on my south bend has a external fan, you need a fan fosure or it will over heat at low speed

101_0804.JPG
 
Back
Top