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Mounting a 9A motor below the lathe

rcbowman

Plastic
Joined
Sep 14, 2023
Hello all -
I am looking at used lathes and the 9A appeals as being big enough, small enough, and so common that there are lots of parts. The issue is that all the ones I've seen have the motor mounted to the rear. This is a major waste of space in my garage, and I would like to be able to mount the motor underneath. Searching forums here I see a few people mentioning it in passing, but it sounds like it may have been a different model that was set up for that.

So the question is, is it possible/reasonable to mount the motor on a SB 9A below the bench if it came with a rear mount? And especially, was this originally 'supported' - as in, did South Bend manuals show you how, or have optional hardware for it? If the latter, how easy is that to find these days? I'm asking this without having had the opportunity to look at the lathes up close. I want to know if I'm barking up the wrong tree and should consider other models instead.

(I have also looked at some very tempting Logans locally, but they have the same issue, and an integral housing for their rear-mounted motors, so it's clear they really can't be remounted, whereas the SB seems potentially possible.)

Thanks in advance!
 
I have a 9a that I'm almost done refurbing. the PO had the motor mounted on the backside of the drive unit. I think he did this to save space and fit a home made chip pan. it uses short pieces of 1/2" pipe as spacers. seems to work ok. might help you save some space
 

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I think the only way to have an underneath motor drive is to replace the headstock to one made for that like the Catalog #'s 8344-ZN, 344ZN and some others as in the old South Bend catalogs on VintageMachinery.org
And, you would need the drive unit to go with the headstock.
 
Hello all -
I am looking at used lathes and the 9A appeals as being big enough, small enough, and so common that there are lots of parts. The issue is that all the ones I've seen have the motor mounted to the rear. This is a major waste of space in my garage, and I would like to be able to mount the motor underneath. Searching forums here I see a few people mentioning it in passing, but it sounds like it may have been a different model that was set up for that.

So the question is, is it possible/reasonable to mount the motor on a SB 9A below the bench if it came with a rear mount? And especially, was this originally 'supported' - as in, did South Bend manuals show you how, or have optional hardware for it? If the latter, how easy is that to find these days? I'm asking this without having had the opportunity to look at the lathes up close. I want to know if I'm barking up the wrong tree and should consider other models instead.

(I have also looked at some very tempting Logans locally, but they have the same issue, and an integral housing for their rear-mounted motors, so it's clear they really can't be remounted, whereas the SB seems potentially possible.)

Thanks in advance!
I, too, am interested in such a conversion and have been thinking about it for several years.
 
You would probably need a gear drive motor with a 3/1 reduction,otherwise the big pulley would have to be outside the frame ,and make the lathe longer ........quite a few belt lathes were "underdriven" ,with motor below the head ......IVe used them,but never looked to see how they were set up.
 
I recall one time when I was little, maybe still in diapers, been too long ago to remember details. Dad had taken the motor/countershaft drive and mounted it up on the wall above the lathe. It worked! I still have the old lathe today but the motor/countershaft is behind the lathe today.
 
Thanks for your replies everyone.

I looked at some of the catalogs and saw the underneath drive models. What was never clear to me was whether they used entirely different headstocks than the rear-drive ones, or if the rear-drive ones could reasonably be adapted to drive from below. I have seen some of the older model SBs from before the war with clearly original overhead mounts (presumably these were a direct adaptation from the older ones driven by belts off of overhead shafts all over a factory ceiling). I'd strongly prefer a lower mount. But the ones that were built for this are (a) harder to move and (b) seem to be a bit rarer.
 
Thanks for your replies everyone.

I looked at some of the catalogs and saw the underneath drive models. What was never clear to me was whether they used entirely different headstocks than the rear-drive ones, or if the rear-drive ones could reasonably be adapted to drive from below. I have seen some of the older model SBs from before the war with clearly original overhead mounts (presumably these were a direct adaptation from the older ones driven by belts off of overhead shafts all over a factory ceiling). I'd strongly prefer a lower mount. But the ones that were built for this are (a) harder to move and (b) seem to be a bit rarer.
Up until the mid 70’s, under drive headstocks and beds were different from the horizontal drive machine. The 70’s design change made them interchangeable (10K only)
 
There is a guy here that did that & documented it a few years back , I saved it but for the life of me I can't remember what I called the file . I'll keep lookin. IIRC he made a jackshaft to do this mod .
animal
 
I recall one time when I was little, maybe still in diapers, been too long ago to remember details. Dad had taken the motor/countershaft drive and mounted it up on the wall above the lathe. It worked! I still have the old lathe today but the motor/countershaft is behind the lathe today.
Same story for me. My dad mounted the drive stuff on the concrete wall behind the lathe. At the time I didn't think much about it but now (70 years later) I recognize that the didn't have room on the lathe bench he had.
 
I made my own countershaft and used a treadmill motor as my SB9 came with neither. It's pretty tight but the whole lathe and drive fits (just) on a 24" deep work bench.IMG20230426193400.jpg
 
Hello all -
I am looking at used lathes and the 9A appeals as being big enough, small enough, and so common that there are lots of parts. The issue is that all the ones I've seen have the motor mounted to the rear. This is a major waste of space in my garage, and I would like to be able to mount the motor underneath. Searching forums here I see a few people mentioning it in passing, but it sounds like it may have been a different model that was set up for that.

So the question is, is it possible/reasonable to mount the motor on a SB 9A below the bench if it came with a rear mount? And especially, was this originally 'supported' - as in, did South Bend manuals show you how, or have optional hardware for it? If the latter, how easy is that to find these days? I'm asking this without having had the opportunity to look at the lathes up close. I want to know if I'm barking up the wrong tree and should consider other models instead.

(I have also looked at some very tempting Logans locally, but they have the same issue, and an integral housing for their rear-mounted motors, so it's clear they really can't be remounted, whereas the SB seems potentially possible.)

Thanks in advance!
Look on YouTube for "Wink's Workshop" He has been doing this on a Harding Cataract
 
Wow, lots of great info here. More than I've seen in my searches. Thanks, everyone.

It turns out @SBLatheman had a previous post in a thread about the specific (apparently unusual) model I'm hoping to buy, offering actual conversion parts for mounting its motor below the bench. I'm hoping it is not as involved a process as the pdf @animal12 posted, though.
 
Up until the mid 70’s, under drive headstocks and beds were different from the horizontal drive machine. The 70’s design change made them interchangeable (10K only)
All this time I've been seeing references to the 10K and assuming it was a new model of 10" lathe. So it's in fact just the updated 9A? And the CL670 is a 10K model? The SB historical site seems to miss a bunch of edge cases.
 
I have an under drive SB and the bed has a large hole in it to accommodate the belt. My previous SB had the rear mounted motor drive and no hole in the bed for the belt. I think it would be difficult to make your rear mounted motor drive to an under drive machine but you could fabricate something to put the motor above the headstock.
 








 
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