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End mills that creep..........

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  • End mills that creep..........

    This popped up on that other forum....

    http://www.practicalmachinist.com/ub...ML/005286.html


    For whatever its worth. There may be a problem with his machine, but the phenomenon does seem to be real.
    1601

    Keep eye on ball.
    Hashim Khan

  • #2
    All he needs to do is ditch the air drawbar for a wrench.I use endmills up to and including 1-1/2 all the time with no problems,he just ain't gettin it tight enough.

    Endmill holders are nice,but the extend the tool out too far for my liking,runout is also an issue,plus I have had the setscrew vibrate loose.
    I just need one more tool,just one!

    Comment


    • #3
      The only times I have ever had endmills, or, any other cutting tools "creep" out/down in the collet (R-8), were the ones I forgot to tighten up in the first place.
      Paying Attention Is Not That Expensive.

      Comment


      • #4
        All I know is that in a holder, they never move, without it, they have.

        Case closed.
        1601

        Keep eye on ball.
        Hashim Khan

        Comment


        • #5
          I've had them creep both ways.

          When using a holder pull the mill out with the screw slightly engaged.
          Let the screw pull the mill back into the holder.

          Using a collet, I put layout stain on the mill/collet after it is mounted.

          If you see a silver line when the milling the mill is pulling out.

          When taking heavy cuts with chatter is the likely time to lose a cutter.

          Power drawbars aren't reliable (most).
          I lost an eight inch face mill out of a spindle (50 mm taper) cause the power draw bar wouldn't hold.

          I made a spanner to fully tighten the drawbar after that one.

          mite

          Comment


          • #6
            I haven't had this problem but then I generally take light cuts and alum,inum is my most popular metal. But, I am wondering.

            I have added a ball thrust bearing to the drawbar for my lathe (SB9) and I find that it makes the job of tightening and releasing the collet a lot easier. Could this also make it easier for the work (or tool) being held in a collet to come loose?

            I have had to repair the drawbar on my mill-drill once already (Chinese quality) and I've thought of buying a thrust bearing for it but haven't done so yet. Would that be a mistake?

            Paul A.
            Paul A.

            Make it fit.
            You can't win and there is a penalty for trying!

            Comment


            • #7
              Usng a power drawbar on a r8 milling machine is a big no-no in my book, I have never seen one that is worth the price, secondly anything that is taking a heavy cut should be put in an endmill holder especially hog mills or large endmills 5/8" or bigger in diameter, even the best collets will slip if put under a heavy cut, anybody that tells you otherwise has never used a cutter to its capacity.

              Comment


              • #8
                Paul,I don't think it would hurt at all.don't sweat the drawbar breaking or stripping either,I always keep an extra just in case.

                Speaking of thust bearings are any of you guys aware that most import mill vises don't have one?I found this to be the case on one Poland and one Taiwan vise and the guys down the street noticed the same.I took ours apart and installed a needle thrust bearing on both,man what a difference that made.
                I just need one more tool,just one!

                Comment

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