Material for large pulley

I should have thought this through more carefully before posting. I just made some measurements and I now realize that a 9 inch diameter is too large for my lathe.

Although my Craftsman is called 12-inch, and the bed will clear a 12 inch diameter, there is no way I could cut the tapered sheaves of a 9 inch pulley. I might be able to make a face cut on a 9 inch part, and I could possibly cut the diameter of the part with the compound and Y axis almost to their travel extremes, but I would not be able to cut the sheave with the compound adjusted for the desired Vee angle. The part would be trying to occupy the same space as the tool holder.

Ulma Doctor's idea of omitting the small sheave is interesting. I can buy a 9-inch pulley.

Thanks everyone, and I apologize for spinning you up on my dead end.
 
JPMacG said:
I should have thought this through more carefully before posting. I just made some measurements and I now realize that a 9 inch diameter is too large for my lathe.

Although my Craftsman is called 12-inch, and the bed will clear a 12 inch diameter, there is no way I could cut the tapered sheaves of a 9 inch pulley. I might be able to make a face cut on a 9 inch part, and I could possibly cut the diameter of the part with the compound and Y axis almost to their travel extremes, but I would not be able to cut the sheave with the compound adjusted for the desired Vee angle. The part would be trying to occupy the same space as the tool holder.

Ulma Doctor's idea of omitting the small sheave is interesting. I can buy a 9-inch pulley.

Thanks everyone, and I apologize for spinning you up on my dead end.
Click to expand...

It's not a dead end. Just have to think about the ways to hold a piece of 9" OD material.
When I turned the 8" sheave on my 9" SBL, I took and drilled and tapped four 3/8-16 holes on the face of the disk on a appropriate bolt circle. Then install four socket head cap screws about 3/4" long. Turned the jaws around on my 4-jaw chuck and chucked on the heads of these socket head cap screws. I was able to cut and finish the entire three step sheave in the one chucking. I think I even did the taper lock bore in the same chucking. Last, all I had to do was remove the cap screws, chuck on one of the steps and face off the other side. The four threaded holes won't hurt anything later. It's just a means of holding a piece of material to cut on.
 
JPMacG said:
Thanks everyone, and I apologize for spinning you up on my dead end.
Click to expand...
There are other ways to hold tools besides what you have been using so far. Think outside the box... One example. Take a decent sized boring bar, 3/4" or bigger, install it on the side of the tool post facing you, bar going to the left and cutting edges facing toward the spindle center. Then "bore" the O.D. of the large work. That is just one idea that would not take me any tooling I do not already have.
 
How bad does the original wobble? Perhaps you could do a handy dandy straightening job? Or is it not concentric with the bore?
Mark S.
 
I made a few pulleys from drops of Corian that I got from a Habitat for Humanity
Surplus store. The material came from where they cut out the sinks. It can also be cut on a table saw. Dulls blades . I bolted two pieces together. And cut the V on a rotary table on the mill.
Jimsehr
Ps material cost me about $5 and I have enough left over to make more.
 
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The original wobbles about 1/4 inch left-right, looking at the lathe from the front. It is enough to cause a noticeable vibration on the lathe bed. I suspect that a previous owner bent it when he removed the pulley from the shaft, as I see hammer marks on the back side of the hub.

As Bob Korves said, I could probably work out a way to cut the Vee on 9-inch material using some sort of clever tool post extension. I do worry about rigidity.

I could try to bend it back, but I'm not sure if the Zamac would cooperate. Probably better to bore and sleeve the hub, but I'm not sure if there is enough material there. In any case, I would need a replacement pulley while I work on this one. I could buy one on eBay and resell later, it if the repair is successful.

I will think it all through - no rush. I have a useable lathe now, I just want to make it better. You all have given me many good ideas. Thanks!
 
I've used car flywheel its balanced and usually free from any mechanics shop, you could use an forming tool to cut the belt shape
 
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