Ah to be where the weather is warm all day.

Well with the house essentially complete, I have received my final inspection, I can now turn my attention back to playing in the shop. Unfortunately the weather has also turned such that we had a dusting of snow on the ground today. So after doing some painting in the basement I decided to go out to the shop this afternoon and play around with the #39 lathe. This lathe is essentially complete but it does need some tinkering with over time. One of the issues I had was that the belt would rub on the left side of the pulley's both top and bottom. This also meant there was a lot of squeaking  going on as the belt rubbed against the pulley side. So after turning the heat on to take the chill out decided to see what I could do about this.
The first thing I checked was to make sure there was a crown on all six pulley steps. There was a crown however I decided to take a large file and carefully dress the pulley's to clean off the gunk and maybe just crown it a little more. With that down we looked at what was happening. Here is a link to a video I shot showing the problem, you can hear the squeak and you can see the belt on the left side of the pulley. If you look closely at the lower pulley you can see the deflection in the belt. I decided that the belt was not riding true due to the pulley shaft not being parallel with each other. I cannot adjust the headstock so that left shimming the upper pulley assembly. I cut some shim stock down and inserted about 30thous of material. Ran the motor up and noticed a very slight improvement. I then upped the thickness to 80 thous and noticed that the belt was a lot better but that the lower section did not improve as much. I looked at the situation and figured that I might be able to move the headstock a little more to the left If I ground out a bit of the support for the upper pulley assembly. Here are two pictures, the first shows the support arm before grinding with some magic marker indications as to where to grind, the second picture shows the grinding complete.

With the grinding complete the headstock was reinserted and probably moved about a 60-80thous to the left. After a quick run I decided to add a little bit more to the upper spacers. With that complete there was 120thous of spacers under the left side of the upper pulley. Now the upper belt rides very close to the centre of each pulley step. The lower belt is still quite close to the pulley flange but it actually rides a lot smoother. Here is a link to a second video shot after all the adjustments. You can see that the belt runs a lot smoother and there is considerably less squeaking. I can live with this adjustment. Just for reference here is a picture showing the shims that I installed, essentially one washer and some aluminium shim stock.

Well now that that is done I guess it will be time to get back to playing with the machines. I think the first thing I'll do will be to try and finish making the steady rest that I had cast a few years ago. This will entail using the Van Norman milling machine mostly. I think that I'll start that just after the new year so look for updates on this blog to start around the end of January. 

Until then stay warm.

Harold