12" Craftsman Commercial...what's with this drive setup?

[G-ManBart]

I tried doing a couple of searches and came up with nothing....sorry if this has been asked before.

I was doing a little reading on the 12" Craftsman Commercial models after seeing one listed at a local auction, and stumbled on a machinery website that had pictures of one they had previous sold. Everything made sense until I saw the picture with the cabinet door open showing the motor. What is below the motor being driven by the second belt?

 

[RJSakowski]

Is the motor 3 phase? You can run a 3, phase motor on a single phase supply by energizing a single winding but a single phase "pony" motor is required to start the 3 phase motor. The pony motor can be significantly less h.p. than the 3 phase motor.

 

[markba633csi]

I have no idea what that is- certainly not stock- makes no sense. Perpetual motion machine maybe?
Should be 1 motor, a countershaft / pulley set and then twin drive belts up to the spindle
-Mark

 

[G-ManBart]

Is the motor 3 phase? You can run a 3, phase motor on a single phase supply by energizing a single winding but a single phase "pony" motor is required to start the 3 phase motor. The pony motor can be significantly less h.p. than the 3 phase motor.

I have no idea, and the listing was long since expired....they had no details about the machine. Very odd!

 

[G-ManBart]

I have no idea what that is- certainly not stock- makes no sense. Perpetual motion machine maybe?
Should be 1 motor, a countershaft / pulley set and then twin drive belts up to the spindle
-Mark

Yeah, that's exactly what I expected to see!

I was looking for pictures of a stock setup because the lathe at the local auction looks pretty decent, and is generally all intact, but the drive belt for the motor is missing, the wires from the motor are disconnected and the drum switch is lying in the chip tray. I'm assuming it needs a motor (not a big deal) and was just wondering about motor frame size when I stumbled onto these pictures.

 

[RJSakowski]

Looking at a You Tube video, the upper motor would be the OEM motor or a replacement for it.

 

[wa5cab]

That is weird. My only guess is that originally the the upper motor was the low-speed one and the lower one gave the high speed. So you switched ranges electrically instead of swapping the motor belt. Note that the pulley on the upper motor is a single groove, not the two-groove originally supplied. However, the lower motor does not appear to be connected. So the only speeds available will be the four low-range ones. Note that the two motors could have been the same. The lower one is probably DC for who knows what reason.

The correct frame numbers are either 56 or 48, depending upon the ID of the motor pulley. The motor pulley normally supplied by the time that this lathe was made would have been 5/8" ID. And the motor a 56 frame size. Largest recommended (or needed) horse power is 3/4.

 

[G-ManBart]

That is weird. My only guess is that originally the the upper motor was the low-speed one and the lower one gave the high speed. So you switched ranges electrically instead of swapping the motor belt. Note that the pulley on the upper motor is a single groove, not the two-groove originally supplied. However, the lower motor does not appear to be connected. So the only speeds available will be the four low-range ones. Note that the two motors could have been the same. The lower one is probably DC for who knows what reason.

The correct frame numbers are either 56 or 48, depending upon the ID of the motor pulley. The motor pulley normally supplied by the time that this lathe was made would have been 5/8" ID. And the motor a 56 frame size. Largest recommended (or needed) horse power is 3/4.

Good stuff...thanks!

I did notice the upper pulley was single-groove and figured out it would have normally be a double after comparing a few other pics and the manual which had me even more confused!

I'm not hurting for a third lathe, but this looks like it could be a fun project and I have a good Baldor 3/4hp 1725rpm motor with a 145 frame on the shelf not doing anything, so if I can get it at the right price I'll grab it. I suspect a 145 frame will fit (maybe with an adapter plate) and it would just be a matter of getting the correct pulley.

 

[wa5cab]

I'm pretty sure that the 5/8" bore motor pulley is still available from Clausing. You will not find a stock 2-step pulley on the market that will work as the OD's of the original on were both odd numbers. They had to be because they needed to match the speed chart and in conjunction with the countershaft 2-step, both fit one belt size in both steps of both pulleys. We do have a reverse-engineered drawing for machining a substitute out of solid round stock. Several have been made from the drawing, which carries the same drawing number as the original, Atlas 10-428 Rev 2.

 

[G-ManBart]

I'm pretty sure that the 5/8" bore motor pulley is still available from Clausing. You will not find a stock 2-step pulley on the market that will work as the OD's of the original on were both odd numbers. They had to be because they needed to match the speed chart and in conjunction with the countershaft 2-step, both fit one belt size in both steps of both pulleys. We do have a reverse-engineered drawing for machining a substitute out of solid round stock. Several have been made from the drawing, which carries the same drawing number as the original, Atlas 10-428 Rev 2.

Thanks! The lathe I'm looking at still has a motor on it and the pulleys are all there, so that's good. I can't recall, but think the motor I have on the shelf has a 3/4" shaft....I'll have to look.