The first thing we did was to finish of the shake adjusting nut. I had turned down the outside just enough to allow the back gear locking pin to clear the nut. This took a couple of test fittings as I wanted to leave as much material as possible. Once we had the outside dimension dialled in I cut some grooves to allow the knurling wheel to do it's job. I had previously purchased a knurling wheel that had a concave pattern to allow me to make knurls that would be similar to a rope lying down. This was not technically a rope knurl however it was close. I also needed to buy a knurling tool holder to fit my Aloris toolpost. This was one of the tools I was waiting for last week. Once the four knurls were done I removed the nut from the lathe and moved it over to the milling machine. Before mounting it in the milling machine I made three marks 120degrees apart. At each location in the middle of the knurl I bored a 1/4" hole down .175". By only going this deep I did not make a through hole that would allow chips to fall in and possibly damage the bearing. These three holes will allow me to use an adjustable pin wrench to either tighten or loosen the nut if required. I actually hope that this can be tightened and loosened by hand. Here are a couple of pictures showing the grooves in the nut and the nut on the mill getting a hole bored.
After this was done I emailed the other owners of these lathes to ask their collective wisdom as to whether I should drill and tap a small hole in the nut to allow me to oil the thrust bearing it sits over. At this time on the original machines there is no way to add oil to this thrust bearing assembly. The only oil it has is what was coated on it when it was installed. At this time it seems no one else has an oil hole either and so far no issues with the bearing. I'll probably just use a slightly heavier oil on this bearing assembly before installing it.
I next took some time to hone out the cast iron bearings. Both bearings had some scoring inside them. There was no large deep scratches just plenty of little ones. I honed both out with a brake hone and then I placed a piece of pipe in the lathe that was just a little bit smaller than the inside of the bearing and wrapped sandpaper on the pipe. I started with 400grit then went up to 1000grit and finished with 2000grit. While the paper was on the pipe I slide the bearing over the paper and then with the lathe turning around 800rpm, moved the bearing by hand in the opposite direction of the rotation of the pipe and sand paper. By going up these three steps I ended up with a pretty smooth silky finish inside the bearings. Some of the scratches are still there but this will just allow some oil to remain to help lubricate the headstock shaft. Once the two bearings were done I did the same treatment to the headstock shaft in the location where the spindle turns inside the bearing. This time I held the sandpaper while the shaft rotated. Again using the 400/1000/2000 grit sandpaper. Once finished there was a very nice polish on the shaft. Since the shaft is hardened steel there were really no gouges or grooves on the surface of the headstock shaft. Here are a few pictures showing the bearings with a before and after shot as well as the headstock.
Once this was done I spent some time cleaning up some of the change gears that came with the lathe and ensuring they would mount on their respective shafts. Unfortunately I do not have a complete set so will have to make some up somewhere down the line. Here is a picture showing the test fit of a couple of these gears.
The last thing I spent some time on was doing a practice repair on a change gear. Since there are a couple of teeth missing from the large back gear and one tooth missing from the large gear on the headstock I wanted to practice on some other stock before doing these repairs. I had purchased some Aluminum bronze welding rod to use with my Tig welder since I do not have an Oxy/Acetylene torch system. I welded up two gears and am not happy with the way they came out. I don't think this will be an issue on these change gears however I don't want the main gears to get this same treatment. I guess this week I'll go out and look at buying a small Victor welding kit with the small pony tanks and then braze up the teeth on the main gears. Of course I'll practice on some smaller change gears first. However here are a couple of pictures of the practice piece. You'll notice I drilled out two small holes to help with anchoring the weld. In the larger gears on the headstock I plan on drilling and tapping two holes per tooth to thread in some 3/16" set screws to use as a foundation for the weld material.
Now I need to try and get my dividing head to work on the mill so that I can mill out the teeth on the repaired change gear. I purchased some gear cutters a while ago so I have the correct cutter for the change gear however the dividing head I purchased for the Van Norman Milling machine does not have the correct dividing plate with it to index the gear correctly. I am missing two plates with the following hole counts.38-39-41-42-43-46, and 47-49-54-58-62-66 holes per plate. I especially need the plate with the 58 and 54 hole count. If anybody reading this might have some plates for a Van Norman dividing head with these hole counts that you would like to sell please contact me through the comment button below.
Well that's all for now. I'll see you all next week with hopefully another installment of the continuing saga on rebuilding this lathe.
Harold
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