Slipping MT2 tailstock

[Makintrax73]

I have occasionally had issues with my lathe tailstock drill chuck mt2 shank slipping. Not necessarily with oversized S&D bits (those too) but even with normal sized 3/8-1/2 bits. They are newish, sharp, CLE-LINE bits, and the belt on my lathe will slip if the lathe jams up hard. So I'm pretty sure there is a lack of lock up in the shank. Its a Logan 9b, there doesn't seem to be a tang slot, so it relies on the taper.

Thoughts on any easy corrections? Polish the shank? Ball hone the tailstock?

 

[WobblyHand]

Might want to blue the taper and check the fit. Check the male taper and see if it is within spec. Before that, stick your finger in the socket, or use a Qtip to feel for roughness. You should be trying to characterize the problem, is it the male or female part.

In my case, I used a reamer to touch up the socket taper because it had internal burs, preventing good contact. I lucked out and a generous HM member loaned me a tapered reamer. The lockup is better now.

Hope this helps a little.

 

[Makintrax73]

Might want to blue the taper and check the fit. Check the male taper and see if it is within spec. Before that, stick your finger in the socket, or use a Qtip to feel for roughness. You should be trying to characterize the problem, is it the male or female part.

In my case, I used a reamer to touch up the socket taper because it had internal burs, preventing good contact. I lucked out and a generous HM member loaned me a tapered reamer. The lockup is better now.

Hope this helps a little.

I have some bluing and some time in the shop this afternoon I'll try that and get some pictures of the contact

 

[RaisedByWolves]

I have some bluing and some time in the shop this afternoon I'll try that and get some pictures of the contact

Yes, do that. Preferably with a new MT tool.

I re trued the MT 4 taper on our big lathe at work by hand via bluing, a barrel sanding point in a hand grinder and different grades of paper and my finger.

It’s amazing how small of an imperfection you can feel with your finger through the paper.

The trick is to have the tailstock quill out and on the bench to ease working on it and to be able to see down the throat to where the bluing is being picked up.

 

[C-Bag]

In my case, I used a reamer to touch up the socket taper because it had internal burs, preventing good contact. I lucked out and a generous HM member loaned me a tapered reamer. The lockup is better now.

I had the same problem. I think mine started because of debris inside the tailstock. I didn’t leave anything in it and once I spun it it got a groove and made it worse. The reamer inside the tailstock and stoning the drill chuck arbor fixed it and I also now leaving the drill chuck arbor in all the time ensures there’s no dust or debris in it. I bought a set of m2/m3 Russian made reamers off eBay and they have done the trick and weren’t that much $$.

 

[pontiac428]

I did the same on my Atlas using Russian reamers. That fixed it, I never had a slip problem after that.

 

[Makintrax73]

I don't know if I came up with anything definitive, but a couple tries with bluing seem to indicate a tilt maybe caused by a bur?

I seem to get rear contact on 1 side and front contact on the other, with circular marks inside the tailstock. Then the next time I tried I got a wide patch next to a bare patch....

 

[benmychree]

Possibly a good reason to consider going to drilling with the carriage via a dedicated bracket with MT on the compound or an Aloris holder with MT tool holder, since it seems that most folks use the system, the holders have a tang slot, spinning is not a possibility. Drilling from the tailstock is likely the greatest cause in inaccuracy due to burrs.

 

[pontiac428]

Chasing the taper with a reamer, it took very little to remove the offending material and restore the tapers to excellence. This fixed my problems without fanfare. Never had holding issues after, and the new owner is getting plenty of use out of it too.

 

[Makintrax73]

I found there are cheap finishing reamers on ebay pretty cheap. Thinking that deep ring just visible in my Pic might be the issue. (When I blow up the Pic I can actually see a bur just at/below the shadow line) I think I'll try a very light touch up with a collet chucked reamer like you are showing.

I'm concerned that on such a small lathe going the tool post drill route might cause issues - the compound locks have twisted on me when using a milling attachment with much depth of cut.

Thinking a piece of delrin turned into a plug might be a good idea when not using the tailstock.