# "creeping" Tail Stock



## building2 (Jul 17, 2015)

I have a Craftsman 6" lathe Model 101.07301 and when boring with a drill chuck mounted in the tail stock the tail stock tends to "creep" backwards no matter how much I tighten it. Has anyone had this problem and if so, how did you correct it? Thanks.


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## JimDawson (Jul 17, 2015)

Is the screw bottoming out before it gets tight? Maybe add a washer under the nut?  You might try cleaning the oil off of the clamp and the bottom of the ways.  Is there enough clearance between the clamp and the bottom of the tail stock?

The only other thing that comes to mind is to glue a strip of emery cloth to the working portions of the clamp to add some  friction there.


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## building2 (Jul 17, 2015)

I already checked the screw for bottoming and it's Ok. I never thought about the oil on the bottom of the ways. I will check that. Thanks for the tips.


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## RJSakowski (Jul 17, 2015)

I have done some very heavy drilling with my Sears/Atlas 6" and not had a problem controlling tailstock creep.  However, I just looked at my clamp and found that I had replaced it with a piece made from some 1/2 x 1-1/4" steel.  Check your clamp for cracks.  The clamp may be distorting under pressure and bottoming out.  I don't recall why I replaced mine (it was probably twenty or thirty years ago) but almost certainly the casting broke.

Bob


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## building2 (Jul 17, 2015)

RJSakowski said:


> I have done some very heavy drilling with my Sears/Atlas 6" and not had a problem controlling tailstock creep.  However, I just looked at my clamp and found that I had replaced it with a piece made from some 1/2 x 1-1/4" steel.  Check your clamp for cracks.  The clamp may be distorting under pressure and bottoming out.  I don't recall why I replaced mine (it was probably twenty or thirty years ago) but almost certainly the casting broke.
> 
> Bob


I will be looking at that today. Thank you.


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## Round in circles (Jul 17, 2015)

Also check that the plate that the tailstock is gripped to the bed  by does not have worn grooves where it has been rubbed by the underside of the ways.
I had such a problem with the thread counter friction pad /plate being well worn in this manner .
I had to make a new one as I couldn't use the old one turned upside down due to the position of the threaded securing hole being too far to one side .


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## Tony Wells (Jul 17, 2015)

Also, don't limit your checking to the clamp, etc. Look at the drill(s), particularly the chisel point. If regular clamp pressure doesn't hold, might be that you are requiring excessive thrust forces because of a drill being mis-ground, or perhaps just needs a good sharpening.


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## T Bredehoft (Jul 17, 2015)

I generally work up to size with smaller drills, the little ones clear the center so the web of a larger drill doesn't have to work.


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## wa5cab (Jul 17, 2015)

I think that all of the possible causes of your problem have been mentioned (or at least I can't think of any more).  But one minor terminology point.  The operation of making or enlarging a hole with a drill bit is generally called "drilling", not boring.


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## RJSakowski (Jul 17, 2015)

A dull drill will definitely increase the axial force required to cut but with that lathe, you should be able to tighten the tailstock clamp so it would take a wrench to advance the quill without having tailstock movement.

When drilling large diameter holes, I find it best to use a smaller drill for the second to last pass because if there is just a few thousandths to remove the drill can auger into the work, possibly ejecting the drill chuck from the taper.  Drilling multiple holes also increases the tendency of the drilled hole to wander with each additional hole.


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## building2 (Jul 17, 2015)

Round in circles said:


> Also check that the plate that the tailstock is gripped to the bed  by does not have worm grooves where it has been rubbed by the underside of the ways.
> I had such a problem with the thread counter friction pad /plate being well worn in this manner .
> I had to make a new one as I couldn't use the old one turned upside down due to the position of the threaded securing hole being too far to one side .


Thank you for the tip. Your suggestion was spot on. When I looked at the plate all appeared normal but, when I examined the plate using a magnifier, I saw a small crack. Apparently when I tighten the nut it caused the crack to open and I really couldn't get it tight enough. I made a new plate today and it seems to have cured the problem. Thanks again to all that offered suggestions.


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## building2 (Jul 17, 2015)

wa5cab said:


> I think that all of the possible causes of your problem have been mentioned (or at least I can't think of any more).  But one minor terminology point.  The operation of making or enlarging a hole with a drill bit is generally called "drilling", not boring.


Thanks for correcting me. You are correct, of course.


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## wa5cab (Jul 18, 2015)

You're welcome.  I tend to hesitate to post minor corrections like this to open fora.  But this forum does have a higher than average of first time machinist's than probably any other on this site.  For the simple reason that usable Atlas machines are much more plentiful on the used market than any other US badge. So sometimes it seems necessary.


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