Here's a few pictures and video of a 1951 12"x24" Craftsman lathe, model number 101.07403 , that I purchased recently. It was built by Atlas for Sears. It's basically an Atlas 10" lathe with a different headstock casting that raises the spindle one inch. So a lot of Atlas parts interchange with it. It has 8 different speeds, 4 via the belt drive and a low-high range via a set of back gears.
It was a greasy mess when I got it (this pic shows how dirty the bed was underneath the headstock) and the back gears on the spindle had some damaged teeth. Plus the power cross feed didn't work (was surprised it had this option in the first place). When I got it home and was unloading it from the van I noticed the tabs on the backside of the base that the motor assembly pivots on were messed up and a couple of cross holes had been drilled for additional bolts to hold it together. It was at this point I decided to tear it down and do a thorough cleaning and inspection.
When I took the apron off the carriage assembly I discovered one of the split nuts in the apron was broken, along with some messed up teeth on the mitre gears(which is why the power cross feed didn't work). Since the stock part for the split nut set was a weak casting I bought an upgraded set made of a better material. The seller I bought them from also had brand new brass nuts for the cross-feed and compound shafts. So I purchased a set of those also.
So far I've purchsed the following used parts for it:
A left side base with good tabs for the electric motor assembly
A set of mitre gears
A thread indicator for the right side of the apron for use when cutting threads.
A nice steady rest for use when cutting long items
A third thread gear bushing and sleeve to allow cutting all the thread options listed in the thread chart I link to towards the bottom of this page, especially 1mm, 1.25mm, and 1.5mm pitch threads
New parts that I bought for the repairs are:
A nicely machined set of gears and pulleys for the spindle
A new set of split nuts with compound and cross feed shaft nuts
20 amp, 125 volt, 3/4 HP motor rated on/off switch
12" Square sheet of 1/4" felt
At the moment I am still putting it back together. Here's a video
I took the other day showing the motor and headstock assembly with the new gears on the spindle. In this pic you can see the new gears on the spindle (they look blurry because it was running at the time the pic was taken). This pic was taken shortly after and shows the cleaned up side gears I just added to the left side of the lathe. Changing these gears around allows the cutting of a wide range of threads per inch. The lathe has 12 different gears, from 20 to 64 teeth.
This past week I was able to pick up some 1/4" thick felt and a hole punch so I could make some new wipers. So today I cut them out and put the apron and saddle back together. When I went to install the replacement mitre gear assembly (the one I bought off eBay last month) that the drive screw slips through on the back of the apron I noticed a lot of slop in the bushing it came with. There was no hole in the bushing for the oil to get though. So I removed the collar holding the mitre gear to the bracket and switched it over to the bracket that was already on the apron as it was in a lot better shape and had very little slop. After it was altogether I shot a squirt of oil in the hole for lubricating the mitre gear that bolts directly to the apron but it just sat there. The oil passage was plugged up. So I had to pull it apart again and clean out the passage in the mounting bolt so oil could get to the gear. I also installed the new reproduction switch plate as the old one was too small for the opening for it and was only held on by one screw. Here's a pic of how it looked at the end of the day.