South Bend 13

Hello South Bend Enthusiasts!

I just brought home my 1941 SB 113-B. It has been in my business machine shop for over 40 years. It got used very rarely but regularly... a few times each year for a very specific job. Well, the floor space became more valuable than the lathe so I brought that lathe to my small home shop.

So, no 3 phase power at home.

Still has 1 HP, 208VAC, 3 phase, 204 frame motor that runs fine.

Question and discussion:

What to use for power at home...
Static phase converter like Temco XS3
Rotary Phase converter like American Rotary AR3
VFD like Lapond on Amazon
Get a 1 phase 220V motor
Other, comments please

Get a VFD for it and use the existing motor. They are really inexpensive. You could also change the motor to single phase but that is more of a pain than hooking up a VFD. Here is what I have on a 1.5 HP 220 volt 3 phase. $100.00 on Ebay.

American made, analog interface, NEMA 4....

KBAC-24D 1HP VFD 115/23VAC GRAY 9987

Best money I've spent so far in this endeavor was on an American Rotary AR-15.

tommy1010 said:

Get a VFD for it and use the existing motor. They are really inexpensive. You could also change the motor to single phase but that is more of a pain than hooking up a VFD. Here is what I have on a 1.5 HP 220 volt 3 phase. $100.00 on Ebay.

View attachment 243138

Click to expand...

I'd VFD it for sure. I went Lapond on amazon and have not been disappointed and would highly recommend. The one linked above that's already NEMA 4 isn't a bad choice either, your money.

Look at it this way: You could get a rotary phase converter to run your 3 phase motor from a single phase line. The rotary converters work really well. What you'll have is a lathe with a single speed motor driving it. That's OK if that's all you want. However, for the same money you could switch over to a single phase motor and end up with the same single speed motor driving the lathe. Again, perfectly OK if that's all you want. Again for the same or LESS money you could go with a VFD and use your original 3 phase motor AND have variable speed drive for the lathe along with some pretty neat additional items such as the ability to overspeed the motor if you want (within reason) and have adjustable motor acceleration and deceleration times, current limits if you want, and a number of other optional settings that the VFD will offer you.

Think about what you want your lathe to do and decide which way to go. In the end, the VFD will probably be less expensive than the other two options.

UPDATE!

I purchased a Lapond VFD from Amazon for $140.

https://www.amazon.com/LAPOND-Inver...PPWG/ref=cm_cr_arp_d_product_top?ie=UTF8&th=1

Got it all hooked up, it seems to work fine. Here is my next question: How much can I get away with on motor/spindle RPM on my old 1941 113-B South Bend lathe?

The name plate RPM is about 1730. Surely, I can turn that motor to 2000 RPM and get some more adjust-ability out of my lathe.
Any comments?

Thanks for any help you all can provide.

Todd