Wooden Pulley?

[Andy Howard]

Anyone have any thoughts or opinions as to the durability of a wooden pulley in the headstock of a lathe?

I am working on converting my jet mini lathe to a vfd drive, but I am having a hard time finding a pulley to fit on the spindle to replace the stock pulley. I was thinking about making one out of maple, or some other hardwood?

It is just one of many ideas I am kicking around for my conversion......damn metric parts.....ever try to find a metric pulley?

Andy

[Gary Max]

I keep the phone # of the local machine shop handey. Buy a pully the is a the right OD with a smaller shaft and have them mill it out. Start off with a good pulley not one of those cheap cast alum ones.

[Jim Becker]

Andy, the problem with the wood pulley is that over time, it will not stay perfectly round due to seasonal wood movement.

[Wes Bischel]

Andy,
Just curious, what's wrong with the original step pulley? If it is in good condition, I would just use it. Unless I'm missing something here.

As for wood pulleys, they were used on flat belt applications all of the time. They were built up in layers of solid stock rotated so the end grain was exposed (IIRC) - kind of an art these days, like pattern making is (has) becoming. These pulleys were in service for many years (some still running today) I don't know how well wood would work for a V belt application though.

FWIW,
Wes

[Keith Burns]

They use wooden bearings in screw conveyors as well. Can't remember the type of wood used. Might be worthwhile to contact a screw conveyor dealer to find out. Unless the pulley would present a danger to you, I'd be tempted to try it.

[Andy Howard]

Wes,

There isnt anything "wrong" with the original step pulley, except for the shaft size of the motor. Here is the situation in more detail than you ever wanted to know.

The original jet pulleys have a 15mm bore for the motor shaft, and a 20mm bore for the headstock. I am going to be getting a motor with a 5/8" shaft. The motor pulley with the 15mm bore will have to be drilled out to 5/8" to fit on the new motor.

I am also going to have to find a longer belt most likely. I am mounting the motor behind the lathe, and running a belt out of the opening covered by the access door on the back of the headstock.

I figured that since v-belts are more widely available and come in more sizes, that it may be easier to use a v-belt for more length choices when trying to get the motor mounted.

I guess I will order a replacement pulley from Jet, and have a machinist somewhere bore it out to 5/8" for me. Then I just have to figure the proper length for a belt and find one or have one made.

Andy

[Wes Bischel]

Andy,
OOPS, rereading your post, I think the Jet doesn't use a V-belt OK, McMaster is still a potential source:
http://www.mcmaster.com/ Look under "power transmission"
There should be info on the type of belts you need - or go all v-belt.

When you mentioned spindle, I thought of the lathe spindle, not the motor.

Good luck,
Wes

[Randy Meijer]

Considering all of the time and expense that will be required to make this conversion, have you considered selling your machine and buying a VS model??

[Andy Howard]

Randy,

I have considered selling my lathe and buying a vs, but it wouldn't fix my problems, and wouldnt be any fun!

The cost will be approximately the same, or a bit less to do my conversion instead of selling and buying a VS model.

I see a few distinct advantages in doing my own conversion.

1. Power! I hear the jet VS is even less powerful than the standard model, and I am unhappy with its power when turning bowls. I think going to a 3/4hp three phase motor will be a bigger jump than just the 1/4hp is appears to be.

2. Reverse! I can do reverse with a 3 phase motor and drive. I understand that there is a way to do this with the jet VS also, but am not too familiar with it.

3. Education. I get to learn about 3 phase motors, and VFD's.

4. RPM range of 0-17,500! Yes, with the VF drive I have I should end up with a spindle speed of 0 all the way to 17,500. I am sure I wont go that high, but it sure is neat to think about. The lower speeds under 500 will probably be helpful with some pieces.

Andy

[Jeff Singleton]

I had a Fay & Egan face lathe for about 20 years and finally sold it 3 years ago. It had maple flatbelt pulleys on both the headstock and jackshaft and a leather pulley for the motor or lineshaft. The leather pulley was laminated and crowned and riveted with metal end caps. We also had one that had leather covered maple pulleys. The maple worked really good but the babbit got the best of me, oil everywhere. I really don't see a problem with making wooden pulleys except for the bore. I would sleeve it with a steel bushing and end caps that would screw on the bushing or use a hydraulic fitting like moulders use. When I was a full time patternmaker I got the job of making new pulleys for a flatbelt lathe. I would use the hardest wood you can find since you are talking about V belts and not flatbelts. Have you thought about just nesting machined pulleys of different diameters to make a gang pulley? Good luck.

Jeff Singleton

[Randy Meijer]

.....RPM range of 0-17,500! Yes, with the VF drive I have I should end up with a spindle speed of 0 all the way to 17,500. I am sure I wont go that high, but it sure is neat to think about. The lower speeds under 500 will probably be helpful with some pieces......

The reverse will be nice as will the slower speeds. I would be very careful about cranking the thing up. It is probably not designed to handle higher speeds and could come apart at worst or have excessive wear at the least. You might want to check with Jet before proceeding too far. They are surely going to discourage you from the project and you will, no doubt, void the warranty; but you might get some information that could be of help on safe upper limits of speed.