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  • #31
    Originally posted by oxford View Post

    I don’t thing there is enough material in the bottom of the saw combined with an undercut on the bottom of the treads to drive it properly for very long.

    Ive seen some stripped out hole saws before, some stuck spinning on the arbor.

    The smaller sizes do it but the force isn’t so bad in them.
    I think it would take a significant amount of force to strip one out under normal use, meaning not over loading it. I can see the larger dia. saws, maybe 3" and up stripping the arbor threads, but not the smaller ones.
    Out of curiosity I checked some of the ones I have, most are Blu Mol, some older some newer, Have an old Capewell set and a few Lenox.
    The tops of the older Capewell saws are just sheet metal, pierced and then threaded. About 5/16" worth of thread.
    Some of the Blu Mol saws are made the same and then I have some that are actually a 3/8" steel disc drilled and tapped and welded to the saw. I guess it depends on how they felt like making them that day.
    The Lenox ones have a 3/16" disc welded to the blade so less thread than the others. But if the saw locks on the pins your not relying on the threads to drive the saw.
    I think if you were to force one hard enough to strip the thread you would most likely see the hex shaft slip in the chuck, I've seen some come pretty close.

    JL.............

    JL.............

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    • #32
      I have a few holesaw arbors that I made with 3/4" solid shanks. Instead of threading the arbor, I turned a boss on the end that just fits inside the thread and use two 1/4-20 Socket head screws through the pin holes for driving. These of course are made for driving in the lathe or mill, but I do have one with a 1/4 dowel pin for a pilot and a 7/16 hex shank.

      https://www.youtube.com/watch?v=Tgr9Jves3x0

      Notice the material is set in the vise on an angle so the cut is self clearing.
      I just need one more tool,just one!

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      • #33
        step 0: inspect the teeth on the saw and make sure they're there and the geometry is reasonably good
        step 1: throw those hex shanked arbors in the trash
        step 2: buy or turn a solid shanked arbor with a precision shoulder that has decent threads that the saw can thread onto
        step 3: power on with low RPMs, eyeball runout, bang on saw with a hammer to get it running truer if it's really bad

        you don't need the drive pins. I have been using a set of solid arbors on holesaws for mitering chromoly tubes for 16 years and have never needed the drive pins. the arbors are self tightening. you might need to straighten and true up the teeth

        honestly, just buy some: https://www.paragonmachineworks.com/...aw-arbors.html I have been ultra-satisfied with mine and for $6-8 a pop, you might as well just buy a couple...
        -paul

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        • #34
          Originally posted by JoeLee View Post
          I think the main reason those saws engage the pins before they bottom out on the threads is so the saw doesn't screw itself down tight on the arbor making it difficult to remove.


          JL.............
          the loose floating pins wailing on one side of the loose holes while the saw floats on a poor thread fit is a lot harder to deal with than simply sticking a screwdriver through the slot and backing the saw off while it's still in the spindle. if that doesn't work, use some channel locks.

          I can see the utility of having the pin setup if you're drilling holes for pipes in 2x10s while framing a house. if you have a spindle on a machine where you can apply a counter torque via a brake or a spanner on the spindle nose, there is zero utility to have that ****ty hex shank and pin setup
          -paul

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          • #35
            Originally posted by psomero View Post

            the loose floating pins wailing on one side of the loose holes while the saw floats on a poor thread fit is a lot harder to deal with than simply sticking a screwdriver through the slot and backing the saw off while it's still in the spindle. if that doesn't work, use some channel locks.

            I can see the utility of having the pin setup if you're drilling holes for pipes in 2x10s while framing a house. if you have a spindle on a machine where you can apply a counter torque via a brake or a spanner on the spindle nose, there is zero utility to have that ****ty hex shank and pin setup
            Those hex shanks are the worst. I could see mine wanting to twist in the chuck when I tried to break the saw loose. Slightly different set up with this arbor, no pins.

            Click image for larger version

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            So I did this, Press fitted a round shank over the hex.......... now I can hold it in a collet. The repeatability increased and so did the accuracy.

            Click image for larger version

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            JL................



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            • #36
              Oxford, you're pretty close on my setup. The only thing different is that you describe a register surface to center the hole saw before bolting it to the arbor- I made up a separate piece that screws into the hole saw and secures into a bored hole in the arbor using a set screw. I don't know that one way is better than the other. Either way you could still use a centering rod or pilot drill bit. I made my arbor with an mt3 shank- you want yours with a hex on it to mount in a drill chuck I presume.
              I seldom do anything within the scope of logical reason and calculated cost/benefit, etc- I'm following my passion-

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              • #37
                Oh one more thing don’t try to use a hole saw in an Albrecht type drill chuck. I had an off brand keyless chuck and it tightened its self till it collapsed the arbor on the pilot and destroying the chuck.

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                • #38
                  Originally posted by true temper View Post
                  Oh one more thing don’t try to use a hole saw in an Albrecht type drill chuck. I had an off brand keyless chuck and it tightened its self till it collapsed the arbor on the pilot and destroying the chuck.
                  I may or may not have also ruined a chuck that way.

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                  • #39
                    Originally posted by darryl View Post
                    you want yours with a hex on it to mount in a drill chuck I presume.
                    I’ll probably do one with a straight shank to go into a collet for the mill and then do one with a hex shank as there is a nice radial drill with a drill Chuck that lives on it that also see some of this work.

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