chuck spun in tailstock - damage - what to do?

[zeeprogrammer]

Hi all,

I've had a couple of times (many) when drilling on the lathe that the chuck in the tailstock started spinning.
This has caused damage to both the chuck and the tailstock.
The pictures show the damage to the chuck and tailstock.
The chuck is easy to replace but I'm worried about the tailstock.

Some questions:

1) How to repair the tailstock? Or am I looking for a replacement?
2) How to prevent this from happening? I suspect the chuck and tailstock weren't clean enough. Swarf in the way would seem to explain some of this.
3) Has this happened to you? What did you do?
4) Is it my method? It doesn't seem to matter if I start drilling with a smaller drill and step up or start with a near-enough drill size. At some point, it goes awry.

Thanks for your help.

[mklotz]

However you fix your problem, get/make some bore cleaning tools so you can keep the crap out of the TS bore...

https://www.homemadetools.net/forum/tools-gun-shop-27453

The shotgun mops are great; they have a near magnetic affinity for all forms of small swarf, ferrous or not.

[crueby]

I had that start happening on my sherline tailstock, as the morse taper got a bit worn over the years. Any dust or chips in there made it a lot worse. Eventually replaced the taper adapter on the chuck. Is yours a morse taper, or something like that? Any defects in the surface, grit or dings, will keep it from gripping. You should be able to put it in, with a little twist, and feel it grab. Look for shiny spots, feel for bumps on the taper.

[crueby]

Looking at the pictures again, looks like the surface on the inside of the tailstock is all chewed, needs to be smooth and shiny. What kind of lathe?

[zeeprogrammer]

Is yours a morse taper, or something like that? Any defects in the surface, grit or dings, will keep it from gripping. You should be able to put it in, with a little twist, and feel it grab. Look for shiny spots, feel for bumps on the taper.

When I insert the chuck I always twist it to ensure it is snug and tight. Still, sometimes it lets go and the chuck spins.

Looking at the pictures again, looks like the surface on the inside of the tailstock is all chewed, needs to be smooth and shiny. What kind of lathe?

It's a Precision Mathews (PM 1030V).  Indeed, it is chewed. The question is, can I fix it or do I need to get a new tailstock (which I suspect is problematic in and of itself.

Thanks.

I don't doubt I did something wrong but I don't know what. I generally clean the chuck's taper as well as the innards of the tailstock.
My suspicion is that, regardless of how clean it is, if the chuck spins then galling may make it worse.
Perhaps it wouldn't have gotten so bad had I taken care of it (don't know how) the first time it happened.

I've had sessions where it happened three times in a row...so I think it just got worse.

[Dave Otto]

Hey Zee

After the first time it spun it was all down hill from there.
If it were me I would try to replace the tail stock quill, (they can't cost that much) and the chuck arbor. Check the fit of the new parts by bluing, which may have been the problem to start with.
If the tapers on the new parts don't fit then you will need to decide how to proceed to correct that. Your lathe is new enough I would think that replacement parts should be available.

Tapers need to be clean and dry, and are usually assembled by a quick linear motion to seat them, (not twisting).

Dave

[Flyboy Jim]

Zee............this is way beyond my expertise, but the first thing I thought, when looking at that tailstock picture, is "just how hard is that tailstock material to cause galling like that'? Would it do that if it was really hardened? 

Jim

[steamer]

Is yours a morse taper, or something like that? Any defects in the surface, grit or dings, will keep it from gripping. You should be able to put it in, with a little twist, and feel it grab. Look for shiny spots, feel for bumps on the taper.

When I insert the chuck I always twist it to ensure it is snug and tight. Still, sometimes it lets go and the chuck spins.

Looking at the pictures again, looks like the surface on the inside of the tailstock is all chewed, needs to be smooth and shiny. What kind of lathe?

It's a Precision Mathews (PM 1030V).  Indeed, it is chewed. The question is, can I fix it or do I need to get a new tailstock (which I suspect is problematic in and of itself.

Thanks.

I don't doubt I did something wrong but I don't know what. I generally clean the chuck's taper as well as the innards of the tailstock.
My suspicion is that, regardless of how clean it is, if the chuck spins then galling may make it worse.
Perhaps it wouldn't have gotten so bad had I taken care of it (don't know how) the first time it happened.

I've had sessions where it happened three times in a row...so I think it just got worse.

Whats the taper Zee?

MT3?   MT2?

[Don1966]

Zee if it’s a Morse taper you can ream it but by hand only to remove the Galling, but you can probably buy a replacement tail stock just a cheap if you can’t borrow a reamer.  I would go with what Dave said.


Don

[steamer]

find out the cost of the quill.....if its really expensive I have  a full set of   MT2 and MT3 roughing and finishing reamers.    I would only use the finishing reamer.....we can cross that bridge if we get there.    Let me know what they say.

Dave

[dparker]

Zee:  If you use the reamer ( Morse taper reamer #2 or #3 which ever one it is ) put a center in the headstock taper and bring it up into the center of the back of the reamer as you advance the tailstock ram until the reamer gets the damage cleaned up.  You can turn the reamer by hand or a wrench if needed. This will assure that you have the reamer aligned with the headstock bore.  ---don

[sco]

I wonder if the cause could be mis-alignment of the headstock and tailstock such that there is a vibration under light load that is releasing the Morse taper.

Easy to check by putting a lever DTI in the chuck and indicating on the tailstock barrel as you turn the chuck.

Simon.

[zeeprogrammer]

Thanks everyone. Very helpful.

I'll look into whether a new quill can be obtained.

Tapers need to be clean and dry, and are usually assembled by a quick linear motion to seat them, (not twisting).

I hadn't known that. Once I inserted the taper, I twisted to see if it was seated. Problem? (There was no twisting movement if it was seated.)

[GordonL]

https://www.banggood.com/MT3-Reamer-No_3-Straight-Shank-Morse-Taper-Reamer-Finishing-Reamer-p-1124927.html?rmmds=search&cur_warehouse=CN

Something like this could work. It is not like you are going to use it more than once or twice. $18.50 is not too bad.

[Domagoj]

Someone correct me if I'm wrong, but judging by the damage in the tailstock, the taper has been sitting improperly for quite a while. Tapers should fit snugly with much larger surface than the narrow band we see here, which would explain the source of the problem.