# Removing collets



## paulinlapine (Feb 24, 2017)

I have a new (to me) mini mill that uses MT3 collets. They seem to be quite hard to remove . What I do is to loosen the drawbar a couple turns and give it several hard taps with a hammer. The collets then come loose and I can remove them. The collets are clean and dry, as is the spindle bore. My question is, should I apply a small amount of lube to the collet before using it, or is it best to use it dry and live with the stubborn removal. I only tighten them up to what I would describe as snug, not overly tight.
Thanks in advance
Paul


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## mikey (Feb 24, 2017)

I very lightly lube the inside of the spindle taper and the outside of the collet. The inside of the collet and the tool I insert into it are clean and dry.


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## Tozguy (Feb 24, 2017)

As Mikey said. Even with grease on the outside of the collet it might need a tap to remove.


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## master of none (Feb 24, 2017)

Also if your not try using a brass hammer ,I just snug in very lightly about a 1/4 of a turn and it works well for me.   Rick


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## ewkearns (Feb 24, 2017)

Any taper less than 7° in considered self locking. Morse tapers are on the order of 3°, so your taper is performing as expected. I was taught to lightly lubricate all tapered items like adapters, collets, mandrels, etc. ....


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## Bob Korves (Feb 24, 2017)

Morse tapers (and B & S 9) have a shallower angle than R8 taper and so will want to stick in the spindle.  They can be tightened less than R8 collets and will still grab the tooling well, and will release better.  Oil can certainly be used on MT and B & S tapers for easier removal.  Some mills have a drawbar that pushes the collet out after loosening it when you continue to unscrew the drawbar.  You might be able to find or make something like that.


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## paulinlapine (Feb 24, 2017)

Thanks for the suggestions, I'll try a little light machine oil on them and see how that works. 

I'm finding that the more I learn, the less I know. This is simply a hobby for me, but a really fun one.


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## Tozguy (Feb 24, 2017)

Not light oil please. It will migrate to the inner surfaces that need to stay clean and dry to hold the work. If you don't have grease use a smidgen of butter.

Tormach calls for anti seize.


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## 12bolts (Feb 24, 2017)

My (MT3) mill also sticks quite firmly. I use a support for the quill when I knock it free as the downfeed was getting a bit of damage



cheers Phil


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## DougD (Feb 24, 2017)

My mill has a NMTB 30 taper, and it grabs  firmly also.  I routinely clean the spindle with a felt wipe (ebay special), and wipe the holder with a rag before inserting.  Then to remove I do similar to what you described in your post. That is I loosen a few turns then tap a couple to three times with a brass hammer, which then drops the holder.  I use the same procedure on my horizontal mill and on a friend BP (R8).  
I guess what I am saying is what you described seemed normal to me questioning only the "...several hard raps....".
doug


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## rgray (Feb 24, 2017)

I'm going to go against the grain and say only clean and dry...no oil or grease. My reason is from experience with high power transfer taper drives. There were those that used never-seize on them to make them easier to disassemble...Problem was they could spin in the taper. Once they spun enough they twisted the attachment bolt off. Also they could seize/tear a small piece of steel in rotation making basically a sideways key. These were extremely hard to remove, some had to be cut off.
My experience with Bridgeport users that lube the taper is that they no longer have a key in the spindle for the collet. They think no  big deal but the reason they have no key is their collet slipped and sheared it off. The key is not for driving force...It is only for line up....the taper must hold the collet...if it doesn't the key will be sheared.
As said your mt3 has a large amount of holding power. But you do not want it to slip so tighten it as tight as the manufacturer recommends and get a brass hammer for removal.


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## bss1 (Feb 24, 2017)

I don't purposely  "lube" collets or the taper. However I do wipe them down with a rag treated with a corrosion inhibitor which leaves an slight film on them as I do with most all bare metals. In the humid climate I live in there must be some corrosion protection which I'm sure adds some level of lubricity.


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## Tozguy (Feb 25, 2017)

All tapers are not created equal. For example I do not lube Jacobs tapers for drill chucks on drill press. Tools with Mt3 tapers neither.

But when it comes to MT3 collets they certainly do get a very light coating of grease on the surfaces that slip by design.


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## mikey (Feb 25, 2017)

Actually, the idea behind lightly lubricating the collet and spindle is to enhance the smooth, even movement of the collet so that it grabs the tool shank evenly and securely. Keeping the collet and tool shank dry also promote this. Lubing a collet isn't intended to make a taper easier to disengage because a taper will grab if properly ground. However, it does seem to require less force to dislodge the collet, which is why I mentioned it.

Just as important is to be sure the collet and spindle are cleaned before use. Just a single little chip on either one will affect accuracy and removal.


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## Bob Korves (Feb 26, 2017)

I wouldn't use anything on 30, 40, or 50 tapers.  They have a large enough angle to drop out easily.  If they are sticking there is other problems.


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## coherent (Feb 26, 2017)

I think many new to machining and mills over tighten the draw bar thinking it has be really tight. Snug is the best word I can think of. Once you get the feel down for the correct tightness, one or two light taps with a poly or brass hammer should be all that's necessary unless your collet or bore is gouged or damaged


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## willthedancer (Feb 26, 2017)

I like chalk on my shallow tapers. The are not as likely to spin, and it eases release. I would never use oil..

Sent from my Moto G Play using Tapatalk


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## GarageGuy (Feb 26, 2017)

I have a Jet-15 mill with a MT3 spindle.  The spindle bore on mine is also very clean and smooth.  I never actually oil the taper, but I do wipe down the collets with a rag that has oil on it when I remove them from the spindle.  I always need to give my draw bar a couple of good raps with a hammer to release the collet.  Draw bars are very cheap and easy to make.  I made mine.  I put an extra long end on it so if it becomes mushroomed from being hit, I can grind it smooth again... for _many_ years to come.  

GG


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## Bob Korves (Feb 26, 2017)

GarageGuy said:


> I have a Jet-15 mill with a MT3 spindle.  The spindle bore on mine is also very clean and smooth.  I never actually oil the taper, but I do wipe down the collets with a rag that has oil on it when I remove them from the spindle.  I always need to give my draw bar a couple of good raps with a hammer to release the collet.  Draw bars are very cheap and easy to make.  I made mine.  I put an extra long end on it so if it becomes mushroomed from being hit, I can grind it smooth again... for _many_ years to come.
> 
> GG


The draw bar is not as important as the spindle bearings are.  Make sure you are not hitting the draw bar hard enough to damage the bearings.


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## GarageGuy (Feb 26, 2017)

Bob Korves said:


> The draw bar is not as important as the spindle bearings are.  Make sure you are not hitting the draw bar hard enough to damage the bearings.



Obviously I don't wail on it, but if that's not the generally accepted way to do it, I'm always open to improvement.  How do you remove your MT3 collets?

GG


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## master of none (Feb 26, 2017)

that's the way I do it cause it wont come out any other way I'm always worried about the bearings.


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## Bob Korves (Feb 26, 2017)

We


GarageGuy said:


> Obviously I don't wail on it, but if that's not the generally accepted way to do it, I'm always open to improvement.  How do you remove your MT3 collets?
> 
> GG


Well, I don't have MT3 collets, I have R8 collets.  Same game, different players.  The MT3 collets have a shallow angle and much longer taper than many other collet types have.  There are several things going on here.  One is how much power and how much pounding the collet's taper is going to have to hold back when cutting.  Second is how much tightening of the collet it will take to prevent slippage.  Third is how much push on the end of the drawbar it is going to take to separate the tapers afterwards.  If it is an easy job, with light load on the spindle to tooling tapers, then you can tighten the drawbar less, and it will be easier to break the tapers apart later.  You can oil, wax, chalk, or otherwise lubricate the tapers to make them easier to get apart, but that will also make them more likely to slip under load at an given tightness.  You can also make a device that pushes the collet out of the taper by continuing turning the drawbar after the thread loosens up.  You can make a support bar to go between table and spindle to support the spindle so the bearings do not have to support the impact of pounding on the drawbar.  Different approaches will be more or less useful for the different issues you are dealing with.  Understand what is happening, and try to use an approach that balances the benefits with the downsides for what you are trying to do on any given job.


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## GarageGuy (Feb 26, 2017)

I don't know what to say.  I guess I've been doing this wrong forever.

GG


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## Tozguy (Feb 27, 2017)

To remove my MT3 collets from the lathe spindle, I use a long 1'' wood dowel through the spindle bore. I never use the drawbar to hammer out the collet.
Usually just a few taps using the dowel as a slide hammer gets the collet out because it is greased. If not then a dead blow hammer is used on the end of the dowel.  
Several light taps is better than one hard one. Provision is made to catch the collet before it leaves the spindle taper and becomes a projectile.


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## 4GSR (Feb 27, 2017)

Back when we had our 9-J Gorton mills, a stuck arbor would happen more often than you expect.  Sometimes they come loose with a light blow from a hammer.  But had one that had a 2" face mill mounted on the arbor.  That one, as the spindle heated up, would tighten up as the face mill was cutting.  So if you didn't pop the arbor loose immediately after finishing that operation and let it cool, the arbor was pretty much shrunk fitted itself to the spindle.  We literally had to beat on it with a 5 lb sledge hammer to get the arbor loose after trying to heat up the spindle by running for about an hour.  Before beating on the spindle, I would place a metal sleeve around the arbor that the spindle would bear against so the beating did not go thru the bearings.  Take about 4 to 5 blows to break the arbor loose!

Oh, BTW, the spindle taper was a No. 10 Brown & Sharpe.  Yuck!


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## Bob Korves (Feb 27, 2017)

I have a friend who spent lots of time working Gorton 9-J's and Master Mills.  He told me the only way they could get the collets to release was to oil them before installation.


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## 4GSR (Feb 27, 2017)

Bob Korves said:


> I have a friend who spent lots of time working Gorton 9-J's and Master Mills.  He told me the only way they could get the collets to release was to oil them before installation.


We never had any collets for our mills, just arbors to hold end mills. Made a collet holder to hold ER 32 collets later in life.  The key to tightening the drawbar was to use only a 6" Crescent Wrench and gently tighten.


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