What size motor for a -south -bend 9"?

Mine's in storage right now, but IIRC, it's a rather over-sized 3/4 horse jobbie. Big as a horse and a half, but they didn't have the insulation we do now. Probably the weakest link isn't the motor, it's the flat belt drive. Not necessarily bad when the tool digs in and the pulley just spins instead of busting the tool off. There's a reason they were popular in schools...

Stan

A 3/4 HP 1725 RPM motor has been fine on my 10" South Bend.

jsw

Same here, on my SB 10L. It's the original motor, and the lathe is a Navy shipboard model from 1945.

Well , mine's a Logan 10" , and I get by just dandy with a 3/4 hp motor . You might consider replacing the clipped leather belt with an appropriate length serp belt from your local auto parts store . I did , and I much prefer it to the slippage I was getting with a clipped belt . The first time you stall a carbide tool in a cut you'll understand ...

The factory specified 1/4 hp for the early 9" models. I put a 1.5 hp one on mine only because I found one cheap and it had the wiring to accomodate the wiring for the drum switch to allow reversing the motor. Here's a link that you might find useful:

I can't say an actual size, but as long as you have to get a motor, make =

it 3 phase & use a VFD. Size it twice what you'd use single phase, so=20 when it's speed is dialed down, you still have enough torque. Variable=20 speed is a VERY nice feature for a lathe.

Bob

A 3/4hp motor and a VFD is just what is in my plan :-) The old leather is relpaced years ago. Some kind of fiber-reinforced belt. Remember it had to be glued together on the lathe. it was 'sharpened' so the joint had the same thickness as the rest of the belt.

Need to do my math. Since I'm living in a part of Europa that uses 50Hz my motor is a 1380 rpm. But I also plan to replace the pulley so I think it will work fine. The original pylley seems to be 53mm. My replacement will be either 70mm or 93mm.

Den 02-06-2011 19:14, Uffe Bærentsen skrev:

Thanks to all for comments. Looks like I'm on the right track with my plans :-)

I don't go by the RPM, but by how the lathe is cutting. When the cutoff bit chatters I slow it down, if steel chips aren't turning yellow or blue I might speed it up.

jsw