Pully On A Treadmill Motor Shaft?

Franko

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I got this treadmill motor several years ago with dreams of putting it on my Grizzly G4000. For various reasons, I never got around to it. Now, I think it would make a great belt grinder motor.treadmill shaft_0424.JPG

It think it is a pretty good motor and I do have a controller that should work with it, but my problem is how do I attach a pully to the motor shaft which is step threaded but has no key groove. It might be possible to cut a key way in it, but it seems like it would not be a minor endeavor.

The shaft is 17mm and the major diameter of the threads is right at .5" with left hand threads.

Any suggestions? Am I missing something simple?
 
I think you may have to make a step collar that would fit and rest against the inner bearing race, and then the pulley would be sandwiched between it and the nut. "Friction drive".
 
When you make your pulley, it also needs to have a step so the retainer nut clamps it against the shoulder.

It's just my opinion, but I wouldn't use an open construction external fan motor for a belt grinder. It will collect swarf. TEFC sealed motors are better for dirty environments like grinding. You could probably make an enclosure for it, though.

GG
 
On the ones I've had the cast pulley/flywheel was the fan for motor cooling. It had around a 6" dia. flywheel and the belt drive pulley around 1" dia all one piece with the threads for the shaft. If you had that it would probably be good to use it or maybe find one. Motor cooling would be nice and the air flow is out on the pto end. A hose or shroud could be added to the other end of the motor so it picks up clean air farther from the sanding.

I've been using a smaller treadmill motor (1 hp) for a sander for 2 years with no fan and it is still working fine. It is an 8" x 3" double wheel sander and mostly gets used for deburing. Not heavy use like a knife grinder.

I run it with a timing belt pulley whose inner dia is larger than the motor shaft. I made a spacer that I set screwed to the motor shaft and then the timing pulley is set screwed to that. Not very ridged but there isn't much pressure there and I haven't had any trouble with it.
 
Couple things Franko, this was supposed to be just a quick & dirty setup for testing the pulley. Meant to cut then turn down the extra meat on the motor pulley, but never got back to that so far... and I have a better (much like yours) motor. But, surprisingly... has worked so well to this point, it remains, waiting for the better motor... still kinda hokey, but works very well tho...

hH1Fe3l.jpg

A very clever guy that goes by Dickeybird on another forum came up with an ingenious inexpensive solution which I bookmarked:

Cooling off a hot treadmill motor
http://bbs.homeshopmachinist.net/threads/47611-Cooling-off-a-hot-treadmill-motor

I will be doing that mod whenever I swap out the "better, newer" motor.

I have that same KB controller on my lathe... love it...
 
Russ, mine has a plastic ducted fan (one broken blade) on the other end that was pressed on small splines on the shaft.

I guess it wouldn't be impossible to mill or grind a flat on either shaft for a set screw. I'd have low expectations for a friction fit against the shoulder on the threaded shaft.
 
I would just file or mill a flat on the shaft and use a setscrew.
 
Nice Cavebob. Is that large circular thing part of the pulley or a flange mount for the motor?

Dickybird is indeed very clever. Who knew you can heat shrink a plastic bottle on a form?
 
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you can try this drive i have use lots of them (fenner drive key less locking device) google it
 
Nice Cavebob. Is that large circular thing part of the pulley or a flange mount for the motor?

Dickybird is indeed very clever. Who knew you can heat shrink a plastic bottle on a form?

That's the original pulley that was mounted on the treadmill motor, like Russ mentioned... the smaller pulley that it connects to used to be mounted on the drive-shaft that propelled the treadmill. Kinda funny, got the whole treadmill free from Craigslist with a warning that it was broken and they just wanted it gone since it was replaced with a new treadmill. What was broken on it was the running belt had a rip on it, something got dropped on the belt, it developed a tear/hole, so they just bought a new one...

I pressed the smaller pulley off of the "drive-shaft", turned a hub out of aluminum to fit the inside diameter of the pulley, then locktighted it together. It's stuck on pretty good so far, no issues. :) 2 set screws on the aluminum inner hub.

Keyway would probably be best/ideal, but if you were to simply drill a starter hole say, 1/8" deep that's larger in diameter than the set screw, it would be easy peasy enough, and bet it would hold fine. You won't be starting/stopping a lot of mass just running a belt.

Forgot to mention, the local auto parts store had the serpentine belt (that correctly fits the pulleys) in stock.
 
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