So, he told me to come get the darn thing out of his garage... Big Ole Arn!

[iclark]

There's also.a rotary phase converter, 2hp, i could get for $400. That doesn't get me the speed control or reverse though...

I would not go the rotary phase converter route. For the reasons that you said, plus the floor space and wiring.

[Stwood_]

Yeah, Reeves drive. Variable speed. I showed the pic of the pulleys to show that they indicate loss of torsion at the lower speed end.

I misunderstood one of the questions earlier, sorry.

Pics of the headstock and under the hood.









Needs a good cleanup eh?

Yes needs some love. Looks to have sat idle for some time.
Motor sure looks clean.

[Gregory of Sherwood Forest]

I found this.

Pricey. And only 2hp. But it does have the fwd/rev, and the potentiometer.

Any thoughts on this one, or should I shoot for a 3hp VFD, sensorless, and build a control box with potentiometer, reverse, etc...??? How tough would that be for a retired accountant with almost nil electrical skills?

[Gregory of Sherwood Forest]

Found this one, too. Great price, with potentiometer, reverse, etc...


http://dealerselectric.com/L510-203-H1-N.asp

[Gregory of Sherwood Forest]

Or this one with NEMA box, can be run sensorless, variable torque or constant torque.

http://dealerselectric.com/N3-203-CS-U.asp

Under $300

[JDS30]

I had a PM 90 with 4" risers and a baldor 3hp motor with a teco FM50


It ended up getting a pot dial and rpm gauge among a few other items.

[wmesquite]

Looking at those internal pics- what a beast!  Defintely heavier duty than I was thinking. PM 90 comparison indeed.  I bet the shop teacher whose pride and joy this was back in the day is not happy with the mess though- and explains a bit why it was offered up. Planning on electrolysis?

That double reduction drivetrain is beefy. If you get rid of the rust it should have no problem transmitting the power from a 2 hp motor run slow, depending on belt condition and pulley wear-though I doubt it has much wear. It looks like it has ridges across the belts- is this correct, and do the motor and spindle pulley have matching grooves? If so you will not have belt slippage.

Since the motor pulley is not a VS pulley- you may be able to replace it at reasonable cost for another shaft size. Given the small motor pulley size and double reduction, you could be below 400 rpm already. If you care, either get a tach, or if you want to know now and can easily shift into low speed when running, put tape on motor pulley to mark it, and have helper rotate a faceplate enough times to rotate the lower pulley 5 times. Count your faceplate turns to give drive ratio, multiply by 1750.
 
VFDs- I haven't used one, but L510 looks like a good choice- you surely don't need the PID control of the N3. NEMA 4 always a plus, but bulky. Otherwise you need to mount a VFD where the chips don't directly fly into it, far end ok but vulnerable, or under tailstock potentially good, but not sure there is room- and they need 3" vertical clearance.  Maybe you should consider a wall mount- or put on far end in enclosure with the face peeking through. The built in pot is handy for testing, initial setup and occasional use, but they are not very substantial and are not designed for heavy use- this from VFD technicians and personal experience. Plan on remote mounting a pot where it is easy to get to when turning.

Controls- I generally suggest reusing original control switches where possible.  Ask giver/PO if he still has them stashed somewhere. There is a built in enclosure under the lamp switch- could use this to house start/stop, and the lamp switch to cut off power between VFD and wall. Can probably find controls that fit the cast enclosure- or mount a small double enclosure as PO did, and have a pot one side, S/S the other. Though the control JDS showed may be an even better option.

[Gregory of Sherwood Forest]

Now I'm confused...

I thought I needed a sensorless drive to get down to 10% of original cycles? If I want to hit 50 RPM, and I'm at ~500 now, then I need a sensorless drive, right? Otherwise, using an FM50, I only get to 25%, or 125 RPM.

<EDIT> Sorry - The L510 and the N3 can be run sensorless. My mistake, I misremembered...

Will I be able to use the L510 (rated for 3HP) for my 1 HP 3 phase motor until I get a 2 or 3 phase motor??

[Gregory of Sherwood Forest]

The N3 does give me braking also. And the box.... and the removable keypad.

Big question that affects me in the short term;

Can I buy either of these, and will they work with either my current 1hp 3ph, or with a future bought 2 or 3 HP motor, provided the motor is properly rated? I don't want to buy a vfd now that won't work if I do decide to upgrade the motor later.

[wmesquite]

The N3 does give me braking also. And the box.... and the removable keypad.

Big question that affects me in the short term;

Can I buy either of these, and will they work with either my current 1hp 3ph, or with a future bought 2 or 3 HP motor, provided the motor is properly rated? I don't want to buy a vfd now that won't work if I do decide to upgrade the motor later.

The enclosure on the N3- is worth getting if you have a nice place to put a bare VFD on the lathe, but this one only protects the wiring going out, not the VFD itself. A removable keypad is probably useful, but would need a semi-protected placement, they are a bit fragile. I assumed the L510 had some braking. The N3 may have more extensive capabilities. Though you may get less out of braking than you think- to stop a big load with fair inertia you might need a separate braking unit and braking resistor(s). I'm sure the N3 is more likely to support this- regardless ask Dealers.

You can definitely use a 3 hp VFD on a 1 hp motor- 2 sizes down is fine.