Tail Stock

[ranferg]

Hello
Recently purchased a used PM 1030 Lathe. Seems to be in very good shape. Haven't found any major issues yet. However, I am having what are probably self-induced issues with the tail stock. I cannot get it to stay consistent with alignment. I turn me a 60 degree piece for the chuck, cut it so it's true, put a dead center in the tail stock and use an Edge tool and indicator to get it as close to zero zero as possible. Turn a 7-8" long piece and it will have taper. Usually a lot, 5 -15 thousandths and always random each time I redo the alignment. One thing I don't know if I have right is the clamping adjustment. The lever will lock it down but the large nut on the front is loose. I haven't been able to find anything telling how that should be adjusted. The machine is very level with no twist. I spent a lot of time getting that right! What am I doing wrong? Thanks.

 

[Ulma Doctor]

does the ts move when it's clamped down?

is the big end of the taper on the TS end or the HS end?

if the former is true, then the TS needs to be adjusted half the error away from you
if the latter is true, the TS needs to be adjusted towards you, half the error.
usually, there are opposing set screws in the TS that control lateral movement.
one screw is loosened on proximal side of the TS, the opposing screw is tightened on the distal side of the TS, as viewed by the operator.
a dial indicator set on the quill of the TS, can indicate how far you are moving the adjustment

 

[RJSakowski]

The large nut that locks the tailstock in position should be locked during alignment and in use. It you are locking it and still get the variation , you may have a misalignment of the tailstock quill. If the axis of the quill isn't parallel with the spindle axis, changing the quill extension will change the location of the dead center relative to the spindle axis.

 

[markba633csi]

I thought the lever and large nut are part of the same mechanism? Perhaps not and the problem is with the lever system only and it's not holding the tailstock securely down when locked?
I would remove the tailstock and inspect it closely- make sure it is fitted to the ways properly, especially the V way

 

[RJSakowski]

I thought the lever and large nut are part of the same mechanism? Perhaps not and the problem is with the lever system only
I would remove the tailstock and inspect it closely- make sure it is fitted to the ways properly, especially the V way

The lever locks the quill and the nut at the bottom of the tailstock locks the tailstock to the ways. For turning on centers, both have to be locked.

 

[Just for fun]

Hello
Recently purchased a used PM 1030 Lathe. Seems to be in very good shape. Haven't found any major issues yet. However, I am having what are probably self-induced issues with the tail stock. I cannot get it to stay consistent with alignment. I turn me a 60 degree piece for the chuck, cut it so it's true, put a dead center in the tail stock and use an Edge tool and indicator to get it as close to zero zero as possible. Turn a 7-8" long piece and it will have taper. Usually a lot, 5 -15 thousandths and always random each time I redo the alignment. One thing I don't know if I have right is the clamping adjustment. The lever will lock it down but the large nut on the front is loose. I haven't been able to find anything telling how that should be adjusted. The machine is very level with no twist. I spent a lot of time getting that right! What am I doing wrong? Thanks.

I don't really understand. What large nut? Can you post a photo of it? On my machine PM 1236T, I can't see the locking nut, it is under the tail stock. Mine has two levers, one to lock the quill and the other locks the tailstock to the ways.

 

[markba633csi]

I thought there were two levers also

 

[Red96]

On the PM1030, the nut is the adjustment for the locking lever. Normal for it to be semi loose. At least it is on mine.

If the locking lever is not securing the tailstock sufficiently to the ways, snug up the nut just a bit. It is normally just finger-tight.

 

[ranferg]

Thanks for all the replies! Found my problem. The clamp set screw by the scale was missing. Once I replaced that and aligned everything and locked that down, I now get repeatability using the Edge tool. Haven't made a cut yet but pretty confident things will work properly now. Thanks again!

 

[markba633csi]

Aha! Good deal, and better a small missing part than a broken part