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  • Polygonal Holes, Keyways

    Found these 2 videos, thought they might be of interest:

    http://www.poliangolar.com/l_eng/04a...ngolar2006.htm
    http://www.poliangolar.com/l_eng/04b_polikey2006.htm

    The Poliangolar looks like something that an HSM'er might just knock together...

    Ian
    All of the gear, no idea...

  • #2
    The pr0n soundtrack is great too!

    I liked the power-broach thing. The first tool made my head hurt.

    Comment


    • #3
      Looks like a rotary broach for use in a mill spindle instead of a lathe tailstock. Thats pretty neat. A rotary broach has been added to my to-do list, but we'll see how long it takes to get there


      http://www.slatertools.com/video.htm

      http://bbs.homeshopmachinist.net/sho...=rotary+broach

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      • #4
        hmmm....the first one reminds me of a few botched mandrel's I've turned out...

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        • #5
          Rotary broaching is really cool. I got a Slater from eBay, and now make my own bits from dead end mills:





          Here;s the rest:

          http://www.frets.com/HomeShopTech/To...achmaking.html
          Cheers,

          Frank Ford
          HomeShopTech

          Comment


          • #6
            I believe making a rotary broach would be possible in the home shop. It is mainly a tool holder set in a bearing that is at an small angle to the main axis. Needs a good thrust bearing as this would be a heavy load. Regular ball bearings would do for the radial bearings. And a simple hole with a set screw would probably do to mount the tool. You would need to do a bit of work on the angle and the geometry of the tool vs the desired hole, but with CAD it should be doable.

            I think I saw some plans for one some time back, possibly here or on that "other" board.
            Paul A.
            SE Texas

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

            Comment


            • #7
              If you haven't been there, check the Slater web site:

              http://www.slatertools.com

              Both videos are interesting.

              If memory serves, the tool wobbles at a one degree angle.
              Cheers,

              Frank Ford
              HomeShopTech

              Comment


              • #8
                Somebody made complete plans and started physical making of it.

                It is not a terribly complex tool. I believe that the cost of Slater ones are extra profit due to low competition.


                A very simple one might be made with only three parts: a spindle, a body, and a tool. Plus one needle and one radial bearing.

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                • #9
                  I have always wondered just how much problem chip removal is
                  Forty plus years and I still have ten toes, ten fingers and both eyes. I must be doing something right.

                  Comment


                  • #10
                    This came up quite recently here: http://bbs.homeshopmachinist.net/showthread.php?t=27232

                    Comment


                    • #11
                      Frank - the slater ones are canted very slightly from the longitudinal lathe axis. I think that 1 or 2 degrees is correct, iirc. However, according to the article that you all referred me to in HSM September 2002, they found they had better results by a 5-6* offset. This requires that your broach be ground to 6-7* relief, respectively. Not sure why there is such a difference in the two angles, though.

                      Comment


                      • #12
                        Originally posted by Teenage_Machinist
                        It is not a terribly complex tool. I believe that the cost of Slater ones are extra profit due to low competition.
                        I see you complain about the price of quality tools quite a bit and I look forward to you going into manufacturing and finally making quality tools for an affordable price(for a limited market) for some of to buy. good luck

                        Comment


                        • #13
                          I learned a hard lesson about rotary broaches last week. I had a job that requires 600 3/4" square holes in 1/4" steel plate. I pulled out the Slater rotary broach and started running the job. Made it through about 60 holes and my spindle started getting noisy. $3500 dollars to rebuild the spindle and the spindle rebuilder tells me that those things are very hard on spindles and they see a lot of spindle damage from them. I think that will be the last time my machine sees a rotary broach.
                          Mark Hockett

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                          • #14
                            re: rotary broaching chip removal

                            Chip removal isn't a big deal. Usually you can just drill out the hole to the same depth as the pre-drill and you'll clean out the chips. If absolutely no chips are allowed, they can be removed with a boring tool or a flat bottom drill. A recess at the bottom of the hole will allow the chip to break clean. The recess diameter should be larger than the the major diameter of the form being broached.

                            Comment


                            • #15
                              Originally posted by Mark Hockett
                              I learned a hard lesson about rotary broaches last week. I had a job that requires 600 3/4" square holes in 1/4" steel plate. I pulled out the Slater rotary broach and started running the job. Made it through about 60 holes and my spindle started getting noisy. $3500 dollars to rebuild the spindle and the spindle rebuilder tells me that those things are very hard on spindles and they see a lot of spindle damage from them. I think that will be the last time my machine sees a rotary broach.

                              Out of curiosity, what was the machine that gave up the ghost?

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