High segment count rings and open/closed thoughts?

Discussion in 'Open-Segment Turnings Forum' started by Brett Niland, Jan 6, 2019.

  1. Brett Niland

    Brett Niland PRO Member

    It seems to me that the ability to make an open segment vessel on projects with a high segment count would eventually cross the line between technically challenging and virtually impossible as the number of segments per row increases. Specifically, the tinier the open spaces, the more obvious cutting errors and alignment problems would become. At higher segment counts this would be visible at tens of thousandths of an inch.

    In your collective experiences where is the line that shan’t be crossed?
     
  2. Bob Beaupre

    Bob Beaupre Administrator Staff Member

    put a number on this?
     
  3. mfisher

    mfisher Super Moderator Staff Member

    Bob and Tom L. have done some amazing work with high numbers (96 segments per ring?). I think it all depends on the size of the vessel. imo, a 120 segments per ring into a 2" diameter ring would have a SL of 0.5236. Where a 10 inch ring would have a SL of 0.2618, The 10" rings is doable. The example I give is for a closed ring not an open segment vessel.
     
  4. Bob Beaupre

    Bob Beaupre Administrator Staff Member

    move the decimal over a 120 segments per ring into a 2" diameter ring would have a SEL of 0.05236
     
  5. Bob Beaupre

    Bob Beaupre Administrator Staff Member

    Tom Lohman does 144 segment pieces quite frequently.
    I recently got an email from him he was selling wedgies in the 288 range
     
  6. Bob Beaupre

    Bob Beaupre Administrator Staff Member

    Ray Feltzmake bowl and Christmas ornaments 2 and 3 inches in diameter at a 96 segment count
     
  7. mfisher

    mfisher Super Moderator Staff Member

    Sound like it all depends on skill level and equipment.
     
  8. Brett Niland

    Brett Niland PRO Member

    Thanks for the replies, and sorry, I didn't do a good job on the question.

    I'm speaking ONLY of open segment projects. Closed segment at high counts is simply a matter (assuming the use of a good glue up jig) of adjusting ring diameter slightly to compensate for SEL cutting errors (or re-cutting/sanding/whatever).

    In an open segment project assuming 144 segments (1.25 degrees) on a 6.2" diameter and providing a generous .5 degree open segment angle, the open space is a mere 0.027". Since even a tiny deviation would be the difference between closing and doubling that open segment gap, it seems to me that an open segment vessel at such a high segment count is fraught with peril due to how visible any variance becomes.

    So my question then is does anyone have any experience with open segmented work at higher segment counts?

    The gallery seems to answer my question pretty well. Bob and some others have some beautiful examples in the 60-72 range. There's a 112 segment piece by Russ Braun (Title: Spring Blossum) that is stunningly well aligned and evenly spaced. And indeed Tom Lohman has some pieces on his site up to 144 segments that are also virtually flawless. So it seems that it's more possible than is immediately evident. Apparently the trick is (as mfisher points out) skill and equipment. Perhaps a measure of aptitude as well. :)

    Thanks again, and any additional thoughts are always appreciated.

    Regards,

    Brett
     
  9. Frank Smith

    Frank Smith Member

    I'm with you Brett. The work of the individuals you mentioned is mind boggling to me! The key is accuracy, skill and patience. I'd have to work on at least two of those three to be able to do work with high segment counts like that.
     
  10. Bob Beaupre

    Bob Beaupre Administrator Staff Member

    Brett, as you work up the segment count you build your skills and find out what is important. Start at a count you feel a little intimidated at. You will learn a lot. next time bump it up a little you will learn a whole lot more. Don't try jumping into a 96, 112 or 144 bowl it will be way too frustrating. Any questions along the way I'm here to try and help.
     

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