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

[TDKPE]

I corrected my post above. I looked at that manual, saw both the 610 rpm for the 4-speed and the 410 rpm for the Reeves version, and promptly did the math using the wrong number.

The loss of torque with the VS version is likely due to the frequency dropping below about 25 Hz (255 rpm), but it could also be due to the belt drive not being able to deliver. A vector drive and 1200 rpm motor should help, but if it's the belt drive, I don't know that there's much you can do other than keeping the motor speed extra-extra low and the Reeves drive speed as high as you can, so the driving sheave diameter is approaching the size of the driven sheave (smaller sheave pitch diameter usually governs - the smaller it is, the less belt is in contact with the groove). That's one of the reasons I think you should mess about with the 1 hp for now.

[MichaelMouse]

You don't have the Reeves, but the 4-choice sheaves?  If so, easy answer is to countershaft the thing and stay mechanical.  Motor at rated rpm will provide all the torque less belt slip.  No electrical slip to worry about. 

You compute the ratio of the sheaves to get rpm delivered.  That will also let you know what was delivered with - betting 1725 - if you're curious. 

http://www.engineeringtoolbox.com/pulley..._1620.html

In your case you know final rpm, so use that to compute motor rpm.

[Stwood_]

Open up that headstock cover and take a picture under there

[TDKPE]

It's a General 260. In pretty darn incredible shape, too.

With that big handle, I'm assuming it has a Reeves drive.

[Stwood_]

I see that. I want a under cover shot.

[Gregory of Sherwood Forest]

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?

[iclark]

Well, you definitely have a Reeve's drive. So, the manual that you found is for a different model than yours unless it also covers the Reeve's model.

For most Reeve's drives systems, the sheaves in that speed control setup are the weak point in the system. If you have a really bad catch and one of the belts does not slip, it can be unfortunate. (The Shopsmith Reeve's is an exception where the little porkchop that connects the speed knob to the sheave adjuster is the weak point.)

You also want to replace the belts on Reeve's drives before they wear enough to slip into the flat section between the sheaves at the axle. The tapered portions of the sheaves are the control range. Note, please. that this is a general statement and not a statement about the current amount of wear on your belts. I cannot tell from the picture.

Ace Hardware is where I find the (Zip Zoom??) turbine oil (light weight machine oil) to lubricate the Reeve's drive in my Shopsmiths. The extendable tube in the nozzle is really helpful.

Also, on Shopsmiths, you really want the works spinning before you adjust the speed. I do not know if that is as critical for the drives like yours. I trust someone with direct experience on this will chime in.

[Gregory of Sherwood Forest]

I'm looking at VFD's now.

I've learned that if I want to get down to the really low speed, the two differing VFD versions (sensorless or standard(?)) are going to make a difference. If my lathe runs 410 RPM and I want to get down to 10% of that and maintain torque, then I have to choose sensorless??

AND the price of those is higher, and require some substantial programming???

Okay, which devices will run a 2-3 HP 3 phase at low AND higher speeds (remember, I'd like 50-2500 rpm range) and maintain torque, although I do understand I may lose some to belt slippage, etc...

I see some with the potentiometer dial built in. I'd want the dial as opposed to the push button, but I'm guessing that I can make a box and build my own for less than the $300 price differential between those models?? Are those higher priced models the only way to get fwd/reverse??

[Gregory of Sherwood Forest]

I found this.

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

[Gregory of Sherwood Forest]

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