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Why not Armstring toolholder instead of tangential/diamond type?

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  • Why not Armstring toolholder instead of tangential/diamond type?

    I've read the threads and it seems that the main selling points of the tangential/diamond toolholders are that resharpening is achieved by grinding only the end face, and that they allow turning and facing without repositioning.

    But can't you do that with the Armstrong type toolholders?

    Many have the toolbit slot broached at an angle for built in backrake, and you could angle the toolpost and grind the front of the toolbit at an angle to give the desired front and side clearances.

    These toolholders are taller than the slots in QCTP's, so material from the top/bottom could be removed at an angle to give the desired back rake.

    A cleaner solution for QCTP is if they would offer toolholders with the toolbit slot at an angle instead of horiozontal.
    Last edited by noah katz; 11-26-2010, 02:55 PM.

  • #2
    The diamond type are designed to be able to turn the OD and face the work without changing tools. You can do the same with a lantern tool post and an armstrong holder but you have to use a cutter with a 86-88 deg angle V nose. That will allow you to turn the OD and face with the same tool.

    There is a guy here that made a tool holder that held a cutter at a back rake angle and an almost 45 deg angle to the work for turning OD and facing and it works. I tested one of his prototypes. I don't know if he went into production or not.

    The only advantage I saw was to finish turn an OD and face the shoulder on a shaft with one tool in one pass. I had been using a 60 deg V nose tool to do that but things always got in the way. For that reason I was going to make a holder that held the cutter at a 45 deg angle to the axis of the spindle.

    EDIT: I went back and looked it up. The holder is the Wimberley Tool Holder featured in the 2010 May/June issue of HSM. His member name is dwimberley on this site in case you want to get one.
    Last edited by Carld; 11-26-2010, 03:29 PM.
    It's only ink and paper

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    • #3
      Originally posted by Carld
      The diamond type are designed to be able to turn the OD and face the work without changing tools. You can do the same with a lantern tool post and an armstrong holder but you have to use a cutter with a 86-88 deg angle V nose. That will allow you to turn the OD and face with the same tool.
      That just requires grinding the front face, right?

      The Wimberly is interesting, thanks.

      Is he selling them now and for how much?

      What does it do that the Armstrong doesn't?

      Anyway, just ordered a couple of Armstrong type from Grizzly.

      Only $10; they're not forged, just high carbon steel, but that will make them easier to modify.
      Last edited by noah katz; 11-26-2010, 05:16 PM.

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      • #4
        Read these threads about the Wimberley tool

        http://bbs.homeshopmachinist.net/sho...ey+tool+holder

        http://bbs.homeshopmachinist.net/sho...ey+tool+holder

        I don't know if he is selling them or for how much. There are photo's in my thread about the tool.

        I think this is his web site.

        http://www.tripodhead.com/

        You grind three faces on the cutter. It doesn't do anything the Armstrong can't do except it works best in a four way tool post or a QC tool post for fast setups. A lantern tool post with Armstrong holders is versatile but slow to setup.

        Armstrong holders come in HSS and carbide and the difference is the angle the cutter is held in the holder. The HSS has back rake and the carbide holder has the hole cut with no back rake. When I had my Logan lathe I had both HSS and carbide holders and sometimes I used carbide in the HSS holder and HSS in the carbide holder. It depended on what I was cutting and what worked. I also had several different thickness of shims to raise the holder in the tool post to suit the job. The one thing I liked about the lantern tool post was I could get in places a four way or QC won't go without special holder adapters. Then you get overhang chatter.
        Last edited by Carld; 11-26-2010, 10:53 PM.
        It's only ink and paper

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        • #5
          I posted this adjustable one in another thread a while ago. It seems a good design with height setting capabilities. I intend making a couplr when I have time

          http://cgi.ebay.co.uk/Lathe-Tool-Hol...item336247f655

          MBB

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