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mill chuck jaws uneven

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  • mill chuck jaws uneven

    ... I am hoping someone can help me with this? I had forgotten how to how to remove my morse taper mill chuck from the tailstock (I last used it as a center drill, months back) and forced things a little by hand when (stupidly) opening and closing the drill chuck. Anyway, I looked up the correct way to remove the chuck and got it off without any problems. Yay me. Anyway, I am able to get the chuck jaw mounted in there, but it looks like it is one tooth off. How to fix this?

    Check out the images.

  • #2
    You may have done irreparable damage to it.
    The way to dismantle a chuck like this is to turn up a tube to push the rear of the tightening collar (the opposite end from the gear teeth) off of the front end. Don't push against the jaws.
    If you have a press, it is an easy job. Sit the chuck with the morse taper downwards through the press while sitting it on the tube and use a smaller tube to push the nose of the chuck.
    When its in bits, you will find out if it is just a piece of scrap metal or not.


    • #3
      I can't see the 2nd pic, so I'm assuming by off you mean the jaw which came out doesn't line up with the other 2 when closed? If that's the case, the only way I can think of to fix it is to press the shell off as old mart said, put the 3 jaws back in and then replace the gear (a circular piece that's in 2 halves) around them. You won't be able to get that jaw back into the chuck in sync with the others any other way.

      Be careful pressing the shell off, it's VERY easy to screw things up and crack the shell. Make sure that the remainng jaws are no more than 1/2 way into the chuck and press against the body (use a socket).


      • #4
        If you find the chuck is beyond repair, then drill a 5/16" hole through the inside of the chuck into the cavity where the end of the morse taper arbor sits, and use a punch to separate them. The morse taper arbor can be reused. Drill chucks are cheap. Get a replacement chuck with a B16 taper fitting.


        • #5
          I'm beginning to think, the OP hasn't been entirely truthful with his story. I recon that it is impossible to get a jaw out without removing the sleeve, but he neglected to mention that, didn't he.


          • #6
            If you disassembled the chuck then you'll have to do it again to synchronize the jaws, Jacobs chucks have a notch code
            on the jaws for that reason but if you don't someway mark where the first jaw is in relation to the others then it's a moot point.
            I'll guess that your chuck will not have any notch codes on it then it's a matter trying the jaws in different positions till they sync.

            And if you got heavy handed with the chuck and one of the jaws came loose, to the point of falling out I'd say it's time for a new chuck.


            • #7
              This is about a 7 dollar chuck at harbor freight. Its like trying to fix a pair of pliers. Edwin Dirnbeck


              • #8
                The only way that jaw can come out like that is if there's missing teeth. Either on the jaw or on the nut. We can't see either.


                • #9
                  There are many resources showing the construction of a Jacobs chuck and how to disassemble, repair, and reassemble.



                  Last edited by PStechPaul; 07-11-2019, 03:38 PM.
                  Paul , P S Technology, Inc. and MrTibbs
                  USA Maryland 21030