Loose tooling in tailstock

J

john shaw

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hello, I have a 9 in. SB lathe. it came with lots of tooling but some of the #2 MT tools do not really seat well in the tailstock. I have been wondering if cutting maybe 1/8 to 1/4 inch off the tailstock socket might tightenup the loose tool fit.
 
Only way to fix it properly is to ream it as well as potentially shorten slightly if needed. Sounds like it's had a hard life and needs refreshing.
 
If some tools seat but others don't, it is unlikely that the socket is the problem. If the tailstock is retracted, it may be that the tang on the tool prevents full engagement with the socket. I cut the tangs back on my MT tooling to permit full socket engagement when the tailstock is just short of full engagement retraction so I can maximize tailstock travel.

You can check for problems with the socket taper by bluing the tool taper with a Sharpie and rotating the tool in the socket. You should see uniform wiping of the bluing. If there is a bright spot in one region only, then there may be a socket or tool issue. Check multiple tools to see if the problem is with the tool or the socket.

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Cutting anything off on an arbitrary whim is a bad move. Start by running the tailstock quill out an inch and see what difference that makes. Then you have a point to make judgement from. Keep in mind that if you cut off a quarter inch for one tool that the other tools that do fit right, now won't. Reaming is sometimes the only answer. But again, if you ream the quill, you make it bigger, not smaller. Use some marking fluid and a known good MT shank to see if there is a burr inside. If so, then ream just enough to remove the burr.

What you are facing is where someone in the past may have reamed a little too heavy and made the quill oversized. At one time, I had 3 lathes with MT-2 tailstocks. And a couple of drill presses. . . In most cases on the lathes, the problem I had was the MT-2 shank wouldn't go in deep enough to release when I cranked the quill in all the way. Rather than reaming, I fiddled around to find what wouldn't seat deep enough and extended the small end a little to make it work right. What you are describing is just the opposite. As though someone in the past faced the same problem and solved it by making the quill larger. Depending on the tooling involved, it might be simpler (cheaper?) to replace the shank.

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Bi11Hudson said:
Cutting anything off on an arbitrary whim is a bad move. Start by running the tailstock quill out an inch and see what difference that makes. Then you have a point to make judgement from. Keep in mind that if you cut off a quarter inch for one tool that the other tools that do fit right, now won't. Reaming is sometimes the only answer. But again, if you ream the quill, you make it bigger, not smaller. Use some marking fluid and a known good MT shank to see if there is a burr inside. If so, then ream just enough to remove the burr.

What you are facing is where someone in the past may have reamed a little too heavy and made the quill oversized. At one time, I had 3 lathes with MT-2 tailstocks. And a couple of drill presses. . . In most cases on the lathes, the problem I had was the MT-2 shank wouldn't go in deep enough to release when I cranked the quill in all the way. Rather than reaming, I fiddled around to find what wouldn't seat deep enough and extended the small end a little to make it work right. What you are describing is just the opposite. As though someone in the past faced the same problem and solved it by making the quill larger. Depending on the tooling involved, it might be simpler (cheaper?) to replace the shank.
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Modification of tooling should never be an arbitrary action.

A standard MT3 taper with tang takes up 1" of my 2-3/4" tailstock travel. In my case , I determined the extension of the tailstock at which the tooling just engaged and trimmed the end of the taper so that it would disengage at a .05" extension. This was done for each tool so all my tooling disengages at the .05" extension. (The exception is a dead center since there is no need for extending the travel of the tailstock when using it.)

I only have one machine with an MT2 socket. If I had more than one, I would have checked each machine for operation before trimming anything. Normally, I would not modify the lathe tailstock lead screw but it might be an action to have all machines disengage at the same point. It would certainly have less consequence than recutting the socket taper.

Keep in mind that the method for dismounting a Morse taper in a drill press is to use a wedge against the tang to unseat the taper so if the tools are intended to be used on such a drill press as well as a lathe, the tang must not be removed.

Should an error in judgement be made and too much material removed, the end of the taper could be drilled and tapped and a set screw added to extend the taper. Once the correct setting is attained, LocTite can be used to fix the screw.
 
Are you sure the tooling that doesn't fit is MT2? There are other tapers out there. As I remember, Jarno is close to the same taper as MT, but different enough to not fit correctly.
 
on my south bend 13" some tooling wont seat until the tailstock is about 1 1/2" out, but then again I have a chuck that wont release when it gets back to the end as it has been drilled and tapped for a draw bar, they all seat properly oonce the tailstock is extended.
 
I had problems ejecting live centers from my tailstock. I made a new feed screw a bit loger than the old one. Solved the problem.
 
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