I needed to turn a ring for my latest project,problem is,I don`t have any Cole jaws or a Longworth chuck,so I had to improvise with the Heath Robinson approach,I screwed some offcuts of some decking boards I had scudding about with 1 1/2 x 1" baton,then tried to mount the assembly on a screw chuck,bit of a cock up there,put batons to close and had to carve a space for chuck to fit,got it mounted on the screw chuck eventualy,then turned a mounting point for the four jaw chuck to fit on the reverse side of assembly.Then came the roughing of a mounting point for the ring to fit on,used a 1/2 " bowl gauge for this,then tidied it up a bit with a square point tool,I mounted on,perfect fit first time yippee,didn`t trust a friction fit so put a bit of hot melt glue on it,just to make sure,turned the front face,then did the same for reverse side of ring,oh I should mention,I have a selection of rings saved from when making bowls and stuff,got the idea from Andy Coates and they come in handy,a couple of pics,their not great,but you`ll get the idea,cheers,
Eric.