How do you center closed segment rings

Discussion in 'Segmented Turnings Forum' started by Fish30114, Aug 9, 2019.

  1. Fish30114

    Fish30114 New Member

    I recently ordered the longworth chuck from Woodturner Pro, and the question I have, is how do you glue together/center closed rings to make say a bowl. I understand how I would center one ring, but how do I glue up subsequent rings, and keep them centered?? I have been feeling my way along, and do not have someone close by to teach me--so excuse my ignorance, but I'm a 58 year old rookie!
     
  2. Blurr60

    Blurr60 PRO Member

    Here’s what I did , I started by setting up a base with a plate chuck or the nova chuck then use the longworth on the tail stock put the ring on the longworth and clamp with the tail stock by cranking tight and let it dry long enough to add another, it’s not exact but it’s better than stacking, by the way I’m a 58 old coger myself lol
     
  3. mfisher

    mfisher Super Moderator Staff Member

  4. Blurr60

    Blurr60 PRO Member

    Oh ya the stomp works too
     
  5. Glenn McCarron

    Glenn McCarron PRO Member

    I will usually mark the previous row with the centre of the segment edge length in four positions ( 0, 90, 180, 270 degrees) and then make sure they line up with the mitre line of the next ring. It is also important to keep the staggering going straight as well so each row stays lined all the way through the project. Sometimes by simply rotating the next ring to a different position can help get more exact.
     
    Jeff Miller likes this.
  6. Fish30114

    Fish30114 New Member

    Blurr60, how do you mount the longworth onto a 2MT to mount into your tailstock. Mine has a hole in the center of it, I haven't measured it but it seems like it's around 7/8" so I just don't know how to mount the Longworth with that hole to a 2MT taper to put it into my tailstock...
     
  7. Gary Beasley

    Gary Beasley PRO Member

    Oneway live centers can use an adaptor available that you can screw your chucks onto expressly for that. I got mine from a dealer at the Dalton symposium a few years ago, I learned it will not fit the copycat versions of the live center even though the thread count was the same, the machining was no the same depth and would not thread on. Resulted in me getting a Oneway live center and giving away the copycat, couldnt be happier as I use it centering pieces on my vacuum chuck to finish off the tenon.
     
  8. Fish30114

    Fish30114 New Member

    Thanks Gary, I have a oneway live center, so I'll look for something that will fit the longworth chuck!
     
  9. Fish30114

    Fish30114 New Member

    Do you know which one fits the Woodturner Pro longworth chuck??
     
  10. Gary Beasley

    Gary Beasley PRO Member

    How do you mount your longworth chuck to your lathe? Normally you would get an adaptor to whatever size your lathe spindle is, then you can use anything you would normally mount for turning.
     
  11. mfisher

    mfisher Super Moderator Staff Member

    Many times I have centered rings the old fashion way. Using a digital caliper. First I place the ring down on a flat surface. Then I place the vessel on the ring as close to center as I can eye ball it. I check to for segment alignment (brick pattern). Then using a caliper end I start checking the distance at 0, 90, 180. 270 degrees. I make minor adjustments to the vessel till the readings are the same. Then I trace around the vessel making the ring to be mounted. I also make alignment marks for ensure the rings will keep the brick pattern going.

    Here is a simple jig to assist in centering that does not involve a Longworth chuck.
    http://www.woodturningonline.com/assets/turning_articles/centering_segemented_bowl_rings.pdf
     
  12. Lloyd Johnson

    Lloyd Johnson Administrator Staff Member

    Gary,

    I did not make the Longworth Chuck to be mounted on the lathe. There are a couple problems with doing that. First, gravity is not your friend. Glue drips on the lathe bed, rings slide and the gluing process ties up a lathe. Instead, I designed it to be used vertically using the Stomper. This makes gravity work for you. My favorite method of using the Stomper is to get a standard wooden bar stool at Walmart for $17 and drill a hole in the center of it and attach the Stomper from underneath the seat. The seat is the perfect size as it lets you rotate the plates of the Longworth attachment to the maximum and the bolts are still supported by the wooden seat.

    The Stomper is NOT a precision instrument - it can’t be when it is made from a $10 sprinkler. But it centers with all the accuracy you need by standing above the Stomper and looking down at the joints. You just have to make sure that the joints are aligned in four 90-degree corners and when they are, the rings are perfectly centered. When you add the weight to the Stomper, the rings will not slide as the Stomper keeps them in place.
     
    Last edited: Aug 20, 2019
    Gary Beasley likes this.
  13. Green_Dragon

    Green_Dragon New Member

    Before I began using a Longworth and Stomper to center my rings I used a Kreg layout tool to center the rings. Once centered I glued short pieces of popsicle sticks with hot glue. After you glue the popsicle sticks in place, make an index mark on the bowl and ring. Apply you glue, line up your index marks and apply clamping weight. The popsicle sticks keep you rings from sliding around once the glue is applied and turn off easily.
    20170805_152314.jpg Temporary Guides.jpg
     
    mfisher likes this.
  14. mfisher

    mfisher Super Moderator Staff Member

    Green Dragon, Pretty much what I was trying to explain in my post. I use a caliper instead of the Kreg layout tool.
     

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