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  • HELP, mill emergency

    I installed my angle head on my variable speed mill, I was tightening the draw bar, on this particular draw bar the hex is held on to the shaft with a dowel pin. Anyway the pin sheared and the hex came off, now the shaft of the draw bar is in the head of the mill about 6 inches down in the hole of the head, any suggestions on how I might be able to get it out. I am freaking out.

    Thanks in advance

    s.r.
    "the ocean is the ultimate solution"

  • #2
    SR,
    Assuming the hexagon end of the draw bar is also the shoulder it tightens on....could you angle the mill head (or swing the whole ram clear of the table if your mill does that) and drop the whole lot out the bottom of the spindle i.e. remove the right angle head with draw bar still attached.

    I suppose it is tight in the taper, so put a length of bar down from the top first and whack the drawbar to free the taper.

    Comment


    • #3
      Does not this drawbar hold a collet etc?

      Therefore, cannot the collet or whatever come out the end of the spindle?

      if the drawbar and whatever it holds are driven out together by tapping on a rod in the end of the spindle, you should be OK. It's also possible that if it is a collet, which presumably is holding something, it can be partly drawn out by removing (twisting and pulling out) whatever it is holding.

      If that doesn't dislodge the collet, it will at least remove the clamping force and make it easy to push out.
      1601

      Keep eye on ball.
      Hashim Khan

      Comment


      • #4
        Peter,

        I'm just guessing, but if it was a case of put a drift down the spindle and give it a whack, he'd probably have thought of that. Could the problem be that, below the hex, there was a collar, and it's this that's tight against a shoulder in the spindle, ie. the tool is still firmly held in the spindle with the drawbar in full tension?

        If so, ouch.

        Hare-brained solution #1:
        Turn the head through 180 degrees, exactly upside-down. Clamp a suitable sized drill in the vise, pointing upwards.
        Run the spindle backwards, and use the quill to feed the spindle onto the drill, cut just enough of the drawbar away to let it be drifted out.

        If the head'll only go half way over, do the whole operation horizontally.

        Ian
        All of the gear, no idea...

        Comment


        • #5
          Without the hex doesn't that mean that the bar is able to travel further into the milling head ?


          if that's the case then don't do anything but drift the draw bar further in with a wooden dowel, it will then totally expose the angle head so you can rotate it off the drawbar and then just remove the drawbar out the bottom of the spindle - You may have to tilt the mills head...

          Comment


          • #6
            Ian,

            Yes, my apologies to the OP (and other readers) for offering such an obvious 'fix', but I can only recall seeing two-piece draw bars of simple construction i.e. a single diameter draw bar pinned to a larger head. I am no doubt about to learn there are other ways of doing it!

            Comment


            • #7
              A couple of pics if possible would be of benefit here.

              Comment


              • #8
                Originally posted by Peter S
                Ian,

                Yes, my apologies to the OP (and other readers) for offering such an obvious 'fix', but I can only recall seeing two-piece draw bars of simple construction i.e. a single diameter draw bar pinned to a larger head. I am no doubt about to learn there are other ways of doing it!

                I don't think it's just you - I think were all stating the same thing,

                guess we'll find out in short order...

                Comment


                • #9
                  Thanks for the replies, Yes the drive is tight (or as tight as it would get until the pin sheared) the hex in it's entirety came off so perhaps it will come out the bottom. To tell you the truth I was so freaked out about this that I didnt think about that although I had just given it some thought right before I signed back on to see if I had any responses. I am going to finish the machining process I have going then give that a try.

                  Will let you know the out come.

                  s.r.
                  "the ocean is the ultimate solution"

                  Comment


                  • #10
                    AK,

                    Yes indeed, re-reading the first post, it does just sound like a parallel shaft & a cross pin which would drift out (or even fall out if spoken to harshly). I hope for him that it is.

                    Mind you, that wouldn't be any fun, now would it?

                    Waiting with baited breath,

                    Ian
                    All of the gear, no idea...

                    Comment


                    • #11
                      Originally posted by steverice
                      I am going to finish the machining process I have going then give that a try.
                      I would NOT continue if the hex head really was the piece that kept it in tension. You may risk your tooling & health by using it.
                      Amount of experience is in direct proportion to the value of broken equipment.

                      Comment


                      • #12
                        There are very few draw-bars without a pin. BUT... the shaft is supposed to be an interference fit onto the head, then the pin. The good bars wll have a grooved solid pin, not a roll pin. I just made another for my Kurt air-bar (Kurt supplies the parts - you machine them to suit the length if like mine it's non-standard), and found out how tricky it is to press a head onto a long 7/16 4140 rod without it bending! (use a pipe fixture). Next time I'll also use moderdate heat.

                        If you need to buy another, rather than the slew of cheap imports and some marginal "Made in USA", check out the Dorian bars on Enco. I have a couple of these for manual machines.
                        Last edited by lakeside53; 06-05-2012, 01:12 PM.

                        Comment


                        • #13
                          Originally posted by Jaakko Fagerlund
                          I would NOT continue if the hex head really was the piece that kept it in tension. You may risk your tooling & health by using it.

                          The draw bar isn't required after the taper is set. This of course assumes both tapers are dry (no oil), clean and... but in general it isn't an issue. The question is whether the taper was really set before the pin sheared.
                          Last edited by lakeside53; 06-05-2012, 01:11 PM.

                          Comment


                          • #14
                            Originally posted by steverice
                            I installed my angle head on my variable speed mill, I was....

                            I assume you know you need a draw bar with longer hex end when using the RA attachment?

                            Comment


                            • #15
                              Originally posted by Peter S
                              Ian,

                              Yes, my apologies to the OP (and other readers) for offering such an obvious 'fix', but I can only recall seeing two-piece draw bars of simple construction i.e. a single diameter draw bar pinned to a larger head. I am no doubt about to learn there are other ways of doing it!
                              I don't that that is inappropriately obvious advice at all, in fact its probably the state of affairs. The OP is "freaking out" and what is obvious or not is a function of experience. It would be a sever design flaw if the remaining part of the draw bar couldn't be pounded on to release the taper as those pins do go eventually. If it was the case, shame shame shame on the designer...and how are you at long hole drilling? kidding, almost assuredly you'll be able to pop a length of rod in there, give it a smack and release the tapered tooling.
                              Last edited by Mcgyver; 06-05-2012, 01:32 PM.
                              .

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