Tailstock alignment

[dickm]

Well, it makes a change from headstock alignment problems!
My "new" Mystro has what I suspect is a design or (unlikely) a wear problem. The tailstock lines up perfectly with the headstock in the vertical plane, but until it's clamped in place, there is about 1mm horizontal play, which means that horizontal alignment is pretty much a matter of luck. (I wonder if this is another reason why I seem to be the only one on the forum using a Mystro ?)
The problem is that the tailstock section that sits between the bed bars is about 7 thou narrower than the gap between the bars, so the whole assembly can "waggle" horizontally. Thanks to Argee and a pic of his Hegner, a possible solution is to try and create an accurate bearing surface on one side of the tailstock, and a spring-loaded ball assembly on the other to press the tailstock into firm contact with the other face, but still allow easy movement. I think I've got a design in my head for doing this, involving some phosphor bronze rod, ball catches and nifty metalwork, but would be interested in any other suggestions. It's possible that very old Graduates or other lathes with two flat bed sections could have a similar problem in the end as a result of wear.

 

[TEP]

Hi Dick.

Have a similar slight problem with my lathe which has got a cast bed. I haven't done anything about it as yet. It was suggested that I could glue a piece of shim on one side of the tail stock which fits into the bed recess.

Touch wood (no pun intended) it has never seemed to bother me when I'm working.

 

[dickm]

Yes, I'd wondered about that as a solution, but was not sure what thickness of shim to use so that it was possible to move the tailstock easily, but still without wobble - didn't want to end up with it either jammed solid or still wobbly .

 

[Dean]

I had the same problem with my Viceroy, shimming it didn't look a long term or reliable fix.

I removed the guide blocks and heated them up to a cherry glow, placed them on an old die block and gave them a good square clout to spread the metal, then left them to cool. When they were cool enough I filed them a little bit at a time until they were a snug fit.

Touch wood :roll: I've had no problem since.

I wouldn't advise trying this method on a modern lathe :shock: It was the only cure I could think of and spare parts for a 40 year old viceroy are like rocking horse XXXX to find.