Pully On A Treadmill Motor Shaft?

I don't know why I had sander in mind. You clearly said G4000. The 17mm dimension made me think of an alternator pulley. Many are 17mm. They are not keyed or set screwed. An alternator on full charge is said to require up to 8 hp to turn. The pulley is just squeezed between a spacer so it clears the housing and a nut and washer on the end of the shaft. The nut is large dia but at 2.5 hp the 1/2 inch nut must be fine for the treadmill motor.

Can a spacer be put on your shaft and the pulley pinched between that and the end nut?

Nice sander/grinder cavebob...!!! Very nicely done.
 
Don't worry, you haven't lost it, Russ. I purchased the motor for the lathe, but never followed up. I am now considering it for my belt grinder.
 
Someone may have already mentioned this, but I didn't see it. The pulley that is supposed to go on that motor shaft is threaded. My motor had a pulley with a smooth section of the bore that slip fitted over the smooth part of the shaft. That was followed by 1/2-13L threads. Turning the right direction, the pulley will lock itself to the shaft. Easiest way to mount a pulley on your motor would be to mimic the original pulley. Either bore and thread an existing pulley, or turn one from scratch. Left hand 1/2-13 taps are available. No keys, flats, or lock nuts needed.

Larry
 
Thanks Larry. That makes sense and is doable. Since It will be used on a belt grinder there won't be any reason to ever reverse it.
 
I'm in the process of adapting a treadmill motor that looks like like caveBob's, to run a drill press.

Franko, you were asking about the "large circular thing" ... That's a single casting incorporating the (serpentine) V-belt pulley and a large flywheel. The motor side of the flywheel has several vanes (mine has 13) that act as a fan to draw air cooling through the motor. You'll notice a narrow plate behind the flywheel, which is about 1" narrower in diameter than the flywheel OD and helps the fan work.

I plan to simply bore out the existing multi-step drive pulley from the drill press, slip it over the serpentine pulley, and hold it with a set screw or two.

Since you don't have the flywheel/pulley for your motor, you will indeed have to make some kind of pulley yourself. One idea you might consider is to use a left-hand nut to secure the pulley, instead of having to thread it after boring. Just don't bore all the way through the pulley, so there'll be a shoulder to locate it against the shoulder of the motor shaft.

PS regarding the article caveBob cited ... that's a very interesting and useful idea! Thanks so much for posting.

It's one of those "flat forehead, high shoulders" things for me, as I once took a short course in blow molding. That's how soda bottles are made. The attached photo shows the injection molded pre-form used for 1 liter bottles. Theoretically, such a bottle could be shrunk back down to that size!
Liter bottle preform.jpg
 
I've seen them do that on How it's Made on TV.

My motor has a plastic cylinder with propellers inside it that is press fitted on the opposite end. I have another of those motors that is slightly smaller and runs on 90V DC. I got carried away buying motors on eBay at that time. The big motor came with the elevation gear motor which is a very cool little gizmo.
 
If you are going to use a setscrew insted of a flat on the shaft. Dimple the shaft. Put the pully on the shaft then with a drill for th thread size of the setscrew drill through the hole into the shaft the depth of the point of the drill. It is much stronger than a flat and won't work loose.
 
Cutting a slot for a woodruff key shouldn't be that hard. You could probably do a good enough job with a Dremel tool and some stubs of worn down abrasive disks. (You save them don't you?)
 
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