Page 1 of 3 123 LastLast
Results 1 to 15 of 37
  1. #1
    Join Date
    Apr 2018
    Location
    Sydney
    Posts
    64

    Default Removing seized mt2 chuck from spindle

    Hi,

    I am attempting to remove a seized collet chuck from a small milling machine spindle.

    Hitting the draw bar has done nothing and even soaking in penetrating oil yielded no results.

    The spindle has been taken apart and there are no signs of any pins which would be holding the chuck inside.

    If I was to heat the spindle with a propane torch or using a small oven, what temperature would be recommended and what possible actions would maximise the chances of the chuck letting go.

  2. #2
    BobL is online now Member: Blue and white apron brigade
    Join Date
    Feb 2006
    Location
    Perth
    Posts
    7,182

    Default

    Quote Originally Posted by ml018 View Post
    Hi,

    I am attempting to remove a seized collet chuck from a small milling machine spindle.

    Hitting the draw bar has done nothing and even soaking in penetrating oil yielded no results.

    The spindle has been taken apart and there are no signs of any pins which would be holding the chuck inside.

    If I was to heat the spindle with a propane torch or using a small oven, what temperature would be recommended and what possible actions would maximise the chances of the chuck letting go.
    I used a hot air gun with 650ºC max temp to remove an MT3 arbor from a mill.
    You might need to cycle it a up and down a few times.

  3. #3
    Join Date
    Sep 2012
    Location
    York, North Yorkshire UK
    Posts
    6,433

    Default

    If you have stripped the spindle and there are no bearings that can get damaged, I would drop a round of brass bar turned to fit in the bore, then a length of steel bar on top of that, give it a smack with a hammer and it should just pop out.

    I assume that there isn't a slot in the spindle for a taper key.
    Best Regards:
    Baron J.

  4. #4
    Join Date
    Jun 2007
    Location
    sydney ( st marys )
    Age
    64
    Posts
    4,887

    Default

    If the spindle taken apart means it is out of the machine use a press.

  5. #5
    Join Date
    Apr 2018
    Location
    Sydney
    Posts
    64

    Default

    No there is no slot for a drift.
    I have heated the spindle in a small oven at around 250 degrees C and gave the drawbar a few wacks with a hammer but nothing happened.
    After 3 failed attempts I have decided to place the entire spindle into kerosene to allow it to penetrate and dissolve some of the grease/oils between the 2 stuck faces.
    There is a very tiny gap on the exterior face of the taper where it might hopefully get a little deeper.

    As for the idea with the press, I do not have one, It would be hard to clamp the piece down (odd shape with the stuck collet chuck) and if something goes wrong, I risk bending the spindle.

  6. #6
    BobL is online now Member: Blue and white apron brigade
    Join Date
    Feb 2006
    Location
    Perth
    Posts
    7,182

    Default

    Quote Originally Posted by ml018 View Post
    No there is no slot for a drift.
    I have heated the spindle in a small oven at around 250 degrees C and gave the drawbar a few wacks with a hammer but nothing happened. .
    250º is not going to do much.

  7. #7
    Join Date
    Apr 2018
    Location
    Sydney
    Posts
    64

    Default

    Quote Originally Posted by BobL View Post
    250º is not going to do much.
    How much would be ideal?

  8. #8
    BobL is online now Member: Blue and white apron brigade
    Join Date
    Feb 2006
    Location
    Perth
    Posts
    7,182

    Default

    Quote Originally Posted by ml018 View Post
    How much would be ideal?
    As much as you get get but obviously not melt the thing or disrupt any hardness properties but as its a fairly large lump of metal a relatively long time will be needed to do that.
    I'd try a propane torch for a 3-5 minutes and see what happens.

  9. #9
    Join Date
    Sep 2010
    Location
    Lebrina
    Posts
    1,910

    Default

    In order to loosen the internal part, you must get the heat into the outer as quickly as possible. Ovens and heat guns are next to useless for this as they just don't have the "horsepower" to get the heat in quickly enough. Oxy acetylene or Oxy propane with large heating tips will be much better choices if you can find them. The idea is to heat the outer, while keeping the outer as cool as possible, the outer expands and loosens its grip on the inner section.

  10. #10
    Join Date
    Sep 2012
    Location
    York, North Yorkshire UK
    Posts
    6,433

    Default

    Wacking the top of the drawbar is not going to do the threads on either part any good ! This is why I suggested what I did.
    As suggested above you need to get heat into the outer section as quickly as possible, before the heat has time to penetrate to the taper.

    Part of the problem with Morse tapers is the length of the taper, they are very long with respect to the diameter and can effectively weld into the socket, particularly if they are not kept clean !

    One other thing, you say that the taper is holding a chuck, if it is a screw on type it would help to remove it, or it could be on a taper of its own, in which case a pair of chuck removal wedges might release the chuck. Either way it would reduce the amount of metal to absorb heat and reduce the inertia.
    Best Regards:
    Baron J.

  11. #11
    Join Date
    Jul 2012
    Location
    Griffith NSW
    Posts
    435

    Default

    Im with pipeclay on this. Its out of the machine, put it in a press. Any local engineering firm will do it for a very small cost, its but a few minutes work.

    Heating it to 650°C is waaay into tempering tempertures. If that spindle is hardened, youll be modifying its properties with temperatures up there. I absolutely would not be doing that without having exhausted the press options first.

  12. #12
    Join Date
    Apr 2012
    Location
    Healesville
    Posts
    2,129

    Default

    Can you slide a suitable length of thick walled tube or a spacer over the collet chuck so that it sits against the spindle and tighten the collet nut firmly agianst the spacer to act as a puller, then hamner the drawbar.
    shed

  13. #13
    Join Date
    Jul 2010
    Location
    Melbourne
    Posts
    9,088

    Default

    On a sample size of one, you could try "Loctite Freeze & Release Penetrating Oil".
    A mate bought an MT3 taper pillar drill with an ejection slot. We gave the drift a fair belting and the chuck stayed put. We gave it a spray and it damn near dropped out by itself.

  14. #14
    BobL is online now Member: Blue and white apron brigade
    Join Date
    Feb 2006
    Location
    Perth
    Posts
    7,182

    Default

    Quote Originally Posted by scottyd View Post
    Im with pipeclay on this. Its out of the machine, put it in a press. Any local engineering firm will do it for a very small cost, its but a few minutes work.

    Heating it to 650°C is waaay into tempering tempertures. If that spindle is hardened, youll be modifying its properties with temperatures up there. I absolutely would not be doing that without having exhausted the press options first.
    Tempering not only requires heat but time - a lump of metal that size can take 1000º for a few minutes with minimal changes in temper mainly because it won't get to 1000º during that time and be at that temperature for long enough.

  15. #15
    Join Date
    Aug 2008
    Location
    near Rockhampton
    Posts
    6,216

    Default

    Need to get a bigger hammer I think. 10lb would be a start.
    Gold, the colour of choice for the discerning person.

Page 1 of 3 123 LastLast

Similar Threads

  1. Replies: 28
    Last Post: 26th Jun 2017, 06:08 PM
  2. Removing a Myford chuck
    By BobL in forum METALWORK GENERAL
    Replies: 21
    Last Post: 15th Jul 2016, 01:00 PM
  3. Removing a Broke Circlip /C-clip From Spindle
    By thumbsucker in forum METALWORK GENERAL
    Replies: 5
    Last Post: 4th Jun 2015, 07:49 PM
  4. Replies: 2
    Last Post: 18th Oct 2014, 03:38 PM
  5. Removing the spindle from a Sharaton 4 1/2"
    By _AL_ in forum THE HERCUS AREA
    Replies: 4
    Last Post: 31st Dec 2011, 11:12 PM

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •