New Chinese R8 collet stuck in Rockwell mill
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  1. #1
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    Default New Chinese R8 collet stuck in Rockwell mill

    I bought a Shars chuck that came with an R8 Collet, mounted it in my small Rockwell mill and cut a couple .25 holes in 6061.

    Won't come out.

    Ive only had the mill a few months, but never need to do more that a couple taps with my rubber mallet to unseat a collet.

    I hit it harder with a heavier mallet and still nothing. I tapped the mouth of the collet from the side with a brass drift a few times - then really layed into from on top with the quill all the way down so it stopped sliding past the spindle brake. WHAM with a 5lb hammer. Wham wham wham.

    That sucker is stuck and I'm out of ideas.

    I can't get that chinese collet out of my mill. Love the chuck for under $50, its a good 'un but
    this sucks. Ball joint puller?

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    Got a hot air gun?

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    Dump penetrating oil down along the drawbar, and leave it alone for a day. Support the quill peripherally against the table with a block of something softer than it, so that you don’t dick up the bearings, and then smack the drawbar with an appropriate tool. If this fails to work, more penetrating oil, and judicious application of a heatgun to aid in penetration. On the next disassembly attempt, submerge the chuck in a container of acetone in which dry ice has been submerged until it stops boiling. That will give you a pseudocryogenic temperature which will probably serve to pop things loose.

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    You did not list the collet size but if it is 1/2" or larger pull it out from the bottom. Completely unthread the 7/16-20 NF draw bar. Now from the bottom thread in a bolt or all thread. Then slid a spacer long enough to get the collet out over the bolt / all thread that sits on the spindle nose but clears the collet. Now add a heavy washer and nut and tighten till it pulls out.

    Andy

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    You did remember to loosen the draw-bar didn't you? (I've never forgotten that, oh no, must have been someone else...)

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    Got it! I dont even know what happened but prob the two bourbons I had while watching the Celtics game - went out to clean the shop and at some point gave it a couple more whacks. Popped right out.

    Now I know the difference between a smack and whack is two brown glasses of suds.

    Thanks for the replies. They will help more than me - next time. PseudoCyrogenic is my new deep six!

    I'll save that insight like an ace in the sleeve.

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    Quote Originally Posted by jonok View Post
    submerge the chuck in a container of acetone in which dry ice has been submerged until it stops boiling. That will give you a pseudocryogenic temperature which will probably serve to pop things loose.
    Hmm. Suppose this would work on a jacobs taper stuck in a drill chuck? Stick the Morse taper in the solution to cool the shank and then whack it?

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    So you locked the quill and beat the crap out of the draw bar with a 5 lb hammer, brilliant....Have you ordered new quill bearings yet?

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    Yep a BFH, Bourbon and spindle bearings aren't a good mix. I'd measure the slot width and depth on that R8 collet, I'm guessing it may be a bit under size and might have hung up on the pin inside the spindle. You can decide to remove it or not while your replacing those bearings since if that's what happened the pin end will be buggered up as well. Check for score marks on the collet slot.

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    Quote Originally Posted by neanderthal mach View Post
    ... might have hung up on the pin inside the spindle...
    Rockwell did not put a pin in their R8 spindle. I bought my mill new in 1974 and have never had an issue with the lack of a pin or had a tool get stuck in the spindle.

    Larry

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    Thanks Larry, I hadn't known that.

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    Check for galling on the upper end. I would also check to see if it’s oversized on there.

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    This is why you don't buy cheap chinese shit.

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    Moonlight, I did not lock it, I lowered it. So it didn't gripe against the brake. I dont think its damaged, its cutting fine. I read every post I could find on PM before making this post- virtually everyone advised "hit it harder"

    It worked.

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    Quote Originally Posted by Mtndew View Post
    This is why you don't buy cheap chinese shit.
    Agreed, you should always buy expensive Chinese shit..much betta foh yoo!

    Stuart

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    Quote Originally Posted by stoneaxe View Post
    Hmm. Suppose this would work on a jacobs taper stuck in a drill chuck? Stick the Morse taper in the solution to cool the shank and then whack it?
    Maybe, but yours may well be welding of the surfaces due to fretting. Regardless, the best way to remove a chuck from a Jacobs taper is to drill a hole through the bottom of the chuck and use a drift to knock out the adapter. Penetrating oil is optional. Open the jaws as wide as possible and drill the largest hole that you can safely do. There is a space between the adapter and chuck so you will know when you have drilled through the chuck.

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    Quote Originally Posted by Rickyb View Post
    Maybe, but yours may well be welding of the surfaces due to fretting. Regardless, the best way to remove a chuck from a Jacobs taper is to drill a hole through the bottom of the chuck and use a drift to knock out the adapter. Penetrating oil is optional. Open the jaws as wide as possible and drill the largest hole that you can safely do. There is a space between the adapter and chuck so you will know when you have drilled through the chuck.
    That ONLY works with keyed style chucks!

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    If you can, I would first try the purpose belt wedges. I've only had them fail once where they could be applied, even on some very crusty garage sale finds. That one needed Rickyb's technique.

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    Quote Originally Posted by helmbelly View Post
    Moonlight, I did not lock it, I lowered it. So it didn't gripe against the brake. I dont think its damaged, its cutting fine. I read every post I could find on PM before making this post- virtually everyone advised "hit it harder"

    It worked.
    Locked or not if the rotating part of the quill was not supported you were beating on the quill bearings, 5 lb hammers are not for milling machine use.

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    Quote Originally Posted by Mtndew View Post
    This is why you don't buy cheap chinese shit.
    There was really no reason to even mention the brand, nor the fact that it was of Chinese origin. It just makes you look bad.

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