Sheldon Tailstock Repair

[Spindle]

This is from my Sheldon T56 P lathe as I received it. There were 2 short setscrews only 4 or 5 threads long which were folded over sideways with the nut pulled almost 1/2 way out of it's hole.

My first thought would be new holes with longer fine thread setscrews, but I'm seeking advice from the more experienced.

[The Metal Butcher]

Never seen dutch keys pulled that way. I'd drill a new set clocked maybe 30° off from those. Possibly make a new nut first if that one is damaged.

[old mart]

If the original fit is reasonably, you could loctite the nut back as near to its original position and when it is cured, drill and tap new holes no larger than the original ones. Keep away from the keyway and there looks like plenty of space for the job exactly as you thought. Use a taper tap and the threads will be self tightening with short grubscrews, but don't overtighten. Looking at the photo, you could probably fit screws double the length of the originals. If the nut ever needs to be removed, heat just enough to break down the loctite, 250C, 482F for 601 grade.

[sarge41]

How well does the threaded insert fit the hole in the tailstock ram. Since most of the normal load is to push, If the threaded insert fits good, I would put it back in and drill and tap for two new setscrews in new locations and locktight them in.
Sarge41

[Spindle]

Thanks everyone, the nut internal threads are still good so I'll proceed with the locktite/clocked longer screws plan. I think a previous owner may have tried to turn the tailstock wheel with the shaft lock engaged. I'll make sure the nut is bottomed in the well upon reassembly.

[The Metal Butcher]

Thanks everyone, the nut internal threads are still good so I'll proceed with the locktite/clocked longer screws plan. I think a previous owner may have tried to turn the tailstock wheel with the shaft lock engaged. I'll make sure the nut is bottomed in the well upon reassembly.

Doubt it. Probably got a tang locked up tight. I've seen more tailstocks damaged by stuck tapers than anything else.

[old mart]

When I got lucky and bought a NOS tailstock quill for the Smart & Brown model A, I knew it was not the exact original type, but the seller includedthe od and length which matched. I was lucky that the pair of backlash adjustable nuts fitted straight in it, but the main difference was that it was intended to be self extracting. I am not a fan of self extracting Morse tapers for the exact reason that TMB mentions. The quill soon had an extractor slot milled in it to use the good old taper wedge. The engraving was also in the wrong place, so I produced new markings every 1/8" with longer lines at the 1/2" and inch up to the full 3" travel.