TailStock Troubles

[ScrapMaker]

Hi all,

Somethings starting to bug me about my tail stock. When I setup my lathe, i made sure that everything was lined up correctly.
on a 12" bar i had less than a thou run out from one end to the other. But when I came to centre drill and then drill the end of the stock, problems arise.
For some reason the chuck always lifts up and to the right when doing any operations using the tail stock eith drill chuck mounted.
There is no movement in the tail stock, even when it is fully extended.
Any ideas what could be causing this?

Thanks

 

[Davyboy]

Hi ScrapMaker. Well I had same prob with my lathe, 7x10 HF lathe. Big OEM 1/2" chuck was fine. Then I got a 0-3/8" chuck that would not hold drills on center. I replaced that one, and life is better. If you have prob's, take out the taper from tailstock, and rotate the chuck 180*, without moving the tailstock if possible. If the point of impact changes, it's in the chuck or the chuck's mount to the taper. then try to re-chuck your drill bit, see if that changes anything.
Also it seems that sometimes my tailstock doesn't clamp on center, in a horizontal plane. If things happen like that, then I try re-clamping it, carefully.

Hope this helps,
Davyboy.

 

[rklopp]

Stick an indicator in the headstock using a 3-jaw chuck or collet chuck and sweep the tailstock bore. If the headstock and tailstock are well aligned you'll read null all around (apart from sag of the indicator). Otherwise, you'll find out whether the offset adjustment is screwed up or whether you might have to put some shim between the upper and lower parts of the tailstock base. This assumes the tailstock has worn low. If it's too high, you have to wonder about the build quality of the machine.