Thank you for your thoughts. I figure you have just built 2 beautiful concentricity checkers and would be able to see the downfalls in a design. I am better at electrical but know I can make things that are functional by slow and steady work taking many measurements. After all early gunsmiths did some wonderful work that I think we have forgotten how. I have seen examples of things pattern makers have done with hand tools and have been in awe....
Thanks again.
Paul in WNY