South Bend 9A, First Lathe and Restoration

[sbx]

Hey All,

I am proud to say that I've graduated from admirer to participant. I recently acquired a new to me South Bend 9A. It's an early 1950's era (serial 33538NAR) 9" Model A.

She seems in decent shape, but with a few quirks. I have never seen something more dirty than this in my life though. And I've done quite a bit of internet searching on restoring these things lately.

An interesting aspect is that its a catalog model CL 744 Z with a 3 1/2 foot bed. Apparently this model came from the factory with a V belt, and 16 speeds. Something I haven't seen much of in my searching.

The bad part, it doesn't have the original drive pulleys. Someone mounted a craftsman motor with homemade motor/pulley mount.

The ways are slightly worn (no factory scraping on the near half), but no major scores or damage.

My plan is to tear her down, clean her, and re-paint. Eventually I'd love to learn scraping and bring it into high precision.. But I think the best bet for a begginer is to use the thing for a while first. It is so dirty I am worried about running it at all without a complete teardown.

Enough, rambling. Here are some pics.

 

[Warrenator]

Nice! I have a complete drive assembly from a 1940's era 9C if you need it, PM me. Also gear covers. Warren

 

[Warrenator]

Oh, also without the stock countershaft assembly your lathe might spin a bit fast. Make sure you feel the bearing caps for warmth and oil it well.

 

[sbx]

Warrenator, - Thanks for the offer.

Your comments bring up my next question. Since I am missing the countershaft assembly, I am thinking of mounting a new motor/VFD combo. Make a permanent mount and go straight to electronic variable speed.

The gear cover is present, just removed for cleaning/painting in one of those pics.

I am currently (slowly) tearing into various parts to clean, and re-paint. I was able to find some Rustoleum Aklyd enamel in "Smoke Gray" (the good ole' oil based type) at a local hardware store, which in CA is almost impossible to find due to the new VOC laws.

I also ordered a rebuild kit with replacement felts and a teardown/restoration guide from Ebay. So, once that arrives I can really start into the guts of the beast.

Other than extreme grime, there is almost no rust to speak of.. thanks to the impenetrable grime!

 

[Warrenator]

The 3 phase motor and vfd combo should work, but for low lathe speeds you might need to drive the motor at 25% of rated speed which i think won't give you the smoothest running or most powerful situation. Might be OK if you oversize the motor, say 1 hp Instead of the nominal 1/2.

I think if you have the full countershaft assembly, it takes a 1700 rpm motor and slows down the rpms with the big pulley to maybe 300 or so, or about 1/5. (I am talking off the top of my head here, i am in Mexico for work and the lathe is in California so I cannot measure the ratio.) The original assembly takes the electric motor pulses through a big spinning pulley that acts as a little bit of a flywheel as well as two rubber belts that have their own inertia and vibration absorbing qualities, so you end up with your main lathe shaft running pretty smooth.

If you use a vfd and 3 phase motor driving the spindle directly, the electric motor will telegraph its' impulses into the spindle and you might end up with surface finish imperfections. If your vfd can spin down to 20% of rated speed smoothly (lets say an 1800 rpm motor) that gives you 360 rpm, maybe a 3 to 1 pulley driving the spindle gives you 120, plus you have back gears available.

That being said, the vfd is a great thing. My lathe has a 3 phase motor with a vfd and i can supposedly spin it from 20% to 150% of the rated speed without problems. I do not know how smooth that 20% would be. I still use countershaft and shift belts for big speed ratio changes. Maybe someone who has done a vfd with direct drive (no countershaft) can chime in. Warren

 

[sbx]

Thanks Warrentator. Makes sense. The more I think about it, I might want to get the countershaft assembly even if I change motors and go the VFD route. Your points are not falling on deaf ears. Plus it would make the lathe complete.

Check your PM's.

 

[janvanruth]

i could be wrong but a 3 phase doesnt have any pulses

a vfd direct drive would give the useable spindle speeds to a ratio of about 1:5
vfd go down to about 0 Hz, but motors dont particularly like to run under 10Hz

 

[sbx]

Since I have some time off for the Holiday, I thought I'd update this thread with some semi finished shots of the lathe restoration, as it sits now. I had meant to update it along the way, but realized that its very hard to take in progress shots covered in grease, grime and paint. But, here ya go.

Included in this fix up so far: Its been in use for about 6 months like this. Just updating the thread for those interested.
- Strip to bare metal and paint all components. Rustoleum Smoke Gray Enamel
- Some sanding and polishing of various parts (some unfortunately less shiny now)
- Slight stoning of way high spots.
- Bore and re-bush the Idler gear to compensate for wear
- Upgrade original motor to 3/4 HP 3P Leeson and Teco 1HP VFD
- New Control Panel with FWD/Rev, speed control, start, stop and (eventually EStop)
- Refurbish Lathe stand with new top, and paint
- Re-felt all oil reseviors

Surprisingly the entire machine was in good order except for a couple minor issues I am still working through. I'll try to update those as I fix or enhance them.

Here she is now.

 

[DoogieB]

Wow, that's quite a difference! Good job!

 

[Surprman]

Nice job with the rebuild. I noticed in a couple of the recent photos that the cross-slide looks a little stubby, like the end was cut off. Is that a modification you made? Usually they have more metal extending over the cross-slide ways. I have a 9C I rebuilt. It is a great little machine (I've actually done a few jobs for people such that I have recouped almost half the purchase price of the lathe, while having fun at the same time!)