How can I straighten a large cast pulley?

At .009" I would think about some epoxy and a spiral flute reamer another way would be a smear of epoxy and clamp a bit of Aluminium in the slot with the edge aligned so that a straight flute reamer could be used.
 
If you have enough shaft on the motor I would try moving the motor pulley out so your belt runs on the center 2 grooves. Having the load off to one side may have been what caused the taper to wear in the bore if it had a little play in it.
 
.030-.060 wall top hat split bushing if you have enough wall thickness on the pulley. just bore the pulley as true as you can get it and make a top hat bushing, split it with a hacksaw making sure the gap is enough to clamp down on the shaft.
 
I ended up using some aluminum shim stock and have the pulley mounted tight and straighter with less torque on the clamp bolt. I now have .090" of wobble, I'm going to leave it there and watch to make sure the aluminum shims don't loosen up. Maybe I'll rebore it later if this doesn't hold.

Thanks for all the ideas.
 
bpimm said:
I ended up using some aluminum shim stock and have the pulley mounted tight and straighter with less torque on the clamp bolt. I now have .090" of wobble, I'm going to leave it there and watch to make sure the aluminum shims don't loosen up. Maybe I'll rebore it later if this doesn't hold.

Thanks for all the ideas.
Click to expand...

The best thing about aluminum shim stock is it's always close at hand:beer mugs:

Cheers,

John
 
Considering the mass of the pulley it is more likely the shaft was bent rather than the pulley. Check the pulley as FOMOGO suggested. I think you will find it reasonably true. If the shaft is bent, remove it from the machine and build up the end (where the pulley fits) and re-machine it. The center in the shaft will be unusable. Set it up in the lathe so the bearing seat runs true. Bore the center true. Support with a tailstock center and re-machine the pulley seat.
 
My compressor is a 311 series built in 1965. It's the smallest 2 stage compressor Kellogg made, and as such wasn't very popular. Having said that I was able to find parts at E compressed Air: https://www.ecompressedair.com/

You might want to check them out if you feel a new pulley is the way to go. With a compressor that old I would probably use the Loctite FixMaster rather than trying to shim it..
 
I'm wrestling with making a new pulley or retrofitting a completely different one for my Atlas Coppco compressor. The pulley is broken into 5 peices (hub 3 splines and outer ring) and it is a humpty dumpty. No way to get it back together again.

I purchased a 'universal' plulley and am machining a custom centre hub for it. I'll let you know how it goes.
 
bpimm said:
Breakage is a concern, but if it bent one way will it bend back? probably not worth the risk.
I tried 2 belts, the motor has a 2 groove pulley but they were not a matched pair and the length difference was to much so I ran the shorter one until it gave up then ran the longer one and now it's given up. I bought a double belt to fix it but I must have measured wrong and it was to long so I tossed it aside and ran it the way it was. I'm in the process of changing the motor pulley to a larger size, should increase the compressor speed about 20%, it's only turning about 325 RPM now, the new pulley will get it up to about 400 RPM. I modified the mounting hardware so with the bigger pulley and more adjustment room the double belt should fit.

With 5HP compressors running single belts I figured that this would be ok with a single belt, it's a 5 HP motor, I don't know what the compressor head is rated for.
Click to expand...

The speed increase will surely give you more air. Check the running amps as the pressure nears the cutoff point to be sure not to overload the motor. you should also check the compressor specs for MAX RPM. If the pump is over speed bearing lubrication & valve operation is compromised. The air discharge temperature will also be elevated & will have more water in it.
 
You must log in or register to reply here.
Back
Top