South Bend Lathe

Hi all, Steve here.  I thought I’d put together a post about one of my major garage projects - the restoration of a South Bend 9A "Workshop" metal lathe.  (A lathe like this is used to make circular or cylindrical parts out of metal).  Owning my own lathe has been a dream of mine since I took Grade 9 shop class in high school.  After we moved here I started to look for one, and it took about 6 months of watching Craigslist and eBay until the ideal lathe popped up.  Here are a few pictures showing what it looked like just after I brought it home.

The previous owner had cleaned it and partially re-assembled it.  However, a few things lead me to not fully trust the re-assembly.  Some parts were re-assembled backwards.  I also noticed that several of the felt wicks that supply oil to moving parts were tar-like and unusable.  Also, I wanted to fully understand how it worked!  So, I decided to completely disassemble, clean, and re-assemble the lathe before I even turned it on.  That whole process took me about a year. 

I took each sub-section of the lathe apart separately.  Each one was completely disassembled down to the last nut and bolt, then each part degreased and cleaned.  For example, here are the various parts for the “apron” and “reversing tumbler”, after disassembly and cleaning:

And here they are re-assembled and ready to go:

Below are the parts from the "quick change gear box" and "change gears".  (These transfer the rotation of the lathe spindle to the lead screw, to drive the carriage back and forth).  This assembly also lets you cut threads on the lathe.

The gear box casting, with the above parts removed:

Here's the gear box re-assembled:

One of the fun parts of the restoration was finding all of the clever ways that the designers used to distribute oil to the moving parts thought the lathe. The gear box above is a good example, where a series of channels throughout the casting distribute oil to several shafts from a single oil reservoir.

While the "South Bend Lathe Works" is no longer around, the company that now uses the name (Grizzly Tools) has the original company's filing cabinets.  For a small fee you can send them your lathe's serial number, and they'll send you a scan of the original serial number card.  After a few months of owning the lathe, curiosity got the best of me and I sent for the card - turns out my lathe was manufactured on April 3rd, 1939!  As far as I can tell, the motor is the only part of the lathe that isn't original.

The kids helped as well with parts of the restoration.  Here's Ross helping me clean up a surplus bench I found at work (which turned out to be the perfect size for the lathe): 

And here’s Madeleine helping to clean the lathe bed.

The motor that came with the lathe was not the correct speed.  After much searching around for a correct replacement, it turns out a family member had the perfect motor sitting in their garage! I flew back to California with it in my carry-on luggage - which raised some eyebrows at security, but I got through with a gentle recommendation to not do it again. The motor was a bit rusty, so I took it apart, cleaned it and repainted it. Here it is before, during a test-mount on the lathe drive unit:

During painting:

And after:

I finished the rebuild about a year ago, and I've had a lot of fun using it since.  I've let Madeleine help with setting up the tailstock (but then set her well back before I turn it on).  Here we are just after making a part together:

People often ask what I use the lathe for.  Lots of things!  Making telescope parts, bike tools, electromagnets, fixing toys and other things around the house.  It was also very useful during my latest restoration project, which I am pictured with below: a small milling machine (to be covered in my next post).