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Thread: Short question: Thread dial with 5 divisions, what gives?

  1. #1
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    Default Short question: Thread dial with 5 divisions, what gives?

    Anyone ever see this before? I noticed this a long long time ago but never got any clear indication as to what it means. I have only threaded once on this lathe and I did not use the dial then.

    The lathe is swedish made, the lead screw is 20mm diameter with an 8 TPI thread, all the lead screws are imperial on this machine. It can cut 49 imperial and 31 metric thread types according to the manual (which does not say anything about the dial) with the norton gear box and set of change gears. If that gives anyone any sort of clue.

    I am not sure what this means myself, maybe it's a thread dial for metric threads? But I have no idea how that would be used... uneven numbers for metric, 5-3-1? and only 2 and 4 for imperial?


  2. #2
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    How many teeth on the gear? Looks homemade and maybe the maker didn't really understand what they were doing...if it's an 8tpi screw and a 32T gear the usual is 8 divisions on the dial.
    Last edited by 1200rpm; 03-17-2019 at 04:36 AM.

  3. #3
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    The lead screw is 8tpi and if the gear has 40 teeth then each of the five graduations would indicate one inch of thread cut. Beyond that surely someone can explain?

  4. #4
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    That does appear to be the case AB....good eye.

    Storebro??
    Last edited by 1200rpm; 03-17-2019 at 06:59 AM.

  5. #5
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    Maybe it's a way to use one thread dial for inch and metric?

  6. #6
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    Quote Originally Posted by The Artful Bodger View Post
    The lead screw is 8tpi and if the gear has 40 teeth then each of the five graduations would indicate one inch of thread cut. Beyond that surely someone can explain?
    There are multile gears in addition to the norton gear box so it's not setup for one particular gear arrangement. I would have thought homemade too, but it matches the factory color and style too well imo.

    @1200rpm It's a Rexvalter, which I believe is part of Storebro.

  7. #7
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    it's *very* hard for me to believe a machine of that quality would have such a crude thread dial....seems out of place....looks like a weldment and a straight cut spur gear....but I concede I don't know anything about that machine other than what I read.

  8. #8
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    Quote Originally Posted by DennisCA View Post
    There are multile gears in addition to the norton gear box so it's not setup for one particular gear arrangement. I would have thought homemade too, but it matches the factory color and style too well imo.

    @1200rpm It's a Rexvalter, which I believe is part of Storebro.
    Regardless of the gear box settings 8 turns of the lead screw moves the tool 1 inch.

    I suspect the indicator is perfect for any whole number inch thread.

  9. #9
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    Quote Originally Posted by 1200rpm View Post
    it's *very* hard for me to believe a machine of that quality would have such a crude thread dial....seems out of place....looks like a weldment and a straight cut spur gear....but I concede I don't know anything about that machine other than what I read.
    I think some guy who really understood the function of a thread dial did a good job of using a gear he had on hand.

  10. #10
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    At any rate, same number every time m should get you going .. on either metric or standard.. but probably not both ..
    Try its scratch cuts, and a pitch guage, is all you need.

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