Removing collets

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

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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. :grin:

GG
 
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. :grin:

GG
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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.
 
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.
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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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