Have you tried https://groups.io/g/tom-senior/files? There are many files there.

Brian

I don't see any shims on the shaft, or anything marked under the end covers. 

It doesn't make sense exactly, since the central part seems like it should be clamped tightly using the missing tube and the outer races shimmed for the preload. Your spindle is different from the drawing, the gear is offset from the centre. I think the lower race outer is held tightly and the upper one moved to give the preload.

Edited By old mart on 03/02/2021 17:07:36

Edited By old mart on 03/02/2021 17:27:09

Tom Senior seemed to make some changes to their designs from time to time which can be confusing. The drawing does not show the oil seal, for instance, and the position of the gear on the spindle varies. Do you know whether oil or grease is used in the head? If it is grease, then a common lithium high melting point would probably be ok. Moly grease is not recommended for ball and roller bearings, as it can make the surface of hardened rolling elements brittle. I used a double lip oil seal without the garter spring on the TS light vertical R8 conversion along with lithium grease and it overheated. The only solution was to completely remove the inner half of the seal, which was ok with grease and the outer lip keeps the swarf out of the bearings.

The seal which overheated was a common size and I made the housing dimensions to fit it. I thought the overheating was due to excessive preload of the bearings and even resorted to setting zero preload before finding that the seal was the source. The overheating occurred at 2000 rpm which was inside the projected 3000 rpm for the spindle.

It is common for grease to be used, unless the seals are very good as it is less likely to leak out everywhere. If you use grease, make sure there is at least 50% air space otherwise the head will overheat. A lithium based grease would be ok, don't use moly grease with ball or roller races.