12 hours ago, Ron Altier said:

It worked, but I was hoping some would say "Its easy, just do this,

 

 

You could add a jack-shaft, and pullies below the lathe and get more speeds both higher, and lower.

48 minutes ago, Larry Buskirk said:

You could add a jack-shaft, and pullies below the lathe and get more speeds both higher, and lower.

 

I did that to this one.

 

2 hours ago, Artie said:

Ohms law. You lower the voltage, you increase the amperage. It’s linear. Amperage is what burns up the wire.

Thanks Artie, when I worked and had a problem with a motor. (Not my field) I'd head to the electricians shop. There I'd get the advice just like your answer. Those guys dealt with motors and control circuits up to 6,000 horse power. I never like being around those fan motors when they started, scared the crap out of me.

3 hours ago, HandyDan said:

 

I did that to this one.

 

Nice job Dan! 

With mine I'll be using 2 shafts and 10 pullies, below the lathe. If I did the math right my slowest speed should be 37.5 RPM.

One of the shafts will also drive an 11" drill press so I can get more speeds out of it also.

Have to wait for the outdoor shop to warm up a bit first though.

 

6 minutes ago, Larry Buskirk said:

With mine I'll be using 2 shafts and 10 pullies, below the lathe.

 

Thanks.  This was a VS lathe but had a planetary gear drive which was poorly designed and the spindle shaft wobbled in the rear bearing.  I retro fit the spindle from a Rockwell 46-111 wood lathe for it.  Took an old aluminum forklift wheel and turned it on the metal lathe to fit into the lathe and fit the spindle shaft to it.  Turned out the VS motor turned at high rpm and had to be cut back by the pulleys.  Works very well but was a lot of work.  I could have cut the motor speed with a different control but feared I would loose torque.

5 hours ago, Ron Altier said:

Thanks Artie, when I worked and had a problem with a motor. (Not my field) I'd head to the electricians shop. There I'd get the advice just like your answer. Those guys dealt with motors and control circuits up to 6,000 horse power. I never like being around those fan motors when they started, scared the crap out of me.

I’m not really a motor guy, but know people who are.

@HandyDan That sounds like a lot of math and engineering. So I will say you da man. I am more from the school of trial and error. I cannot tell you how many ideas I had and took several times to get it where I needed it to be.

13 hours ago, Gerald said:

That sounds like a lot of math and engineering.

Not Dan, but actually not that much math. I used an online pulley speed calculator that you plug in the pulley size, and driven speed. 

It does get a bit confusing when using multiple step, and single groove pullies in combination.

You have to determine the first set, and then use those numbers to determine the second set, etc., etc., etc..

One of these days I'm going to have to make a chart/graph for the various speed combinations. 

On 1/15/2021 at 12:09 PM, Ron Altier said:

Thanks Artie, when I worked and had a problem with a motor. (Not my field) I'd head to the electricians shop. There I'd get the advice just like your answer. Those guys dealt with motors and control circuits up to 6,000 horse power. I never like being around those fan motors when they started, scared the crap out of me.

Ha ha...reminds me of a place i worked many, many years ago which had a hydraulic elevator with the pump in the basement (which was also used for storage and the phone switching equipment.   If you were down there when that pump kicked off....   i think i jumped every time. 

On 1/15/2021 at 8:17 PM, Gerald said:

That sounds like a lot of math and engineering.

 

A set of step pulleys saves a lot of math.  I only use this lathe for big items which I rarely do but it is nice to have the capability.

1 hour ago, HandyDan said:

A set of step pulleys saves a lot of math. 

 

...Let's see now 3 sets of step pullies, and 2 sets of single groove pullies, and a half/double speed attachment, what could be so confusing about that?