Parallel arm compass - video

Parallel arm compass. By Valentin Felder (thanks to mklotz for the discovery). 14:35 video:

https://www.youtube.com/watch?v=Vx2QFlEgfpo

There are, of course, other ways to keep the pivot and scribe/lead parallel. The easiest way is to use a beam compass. The drafting compass style to which Felder refers works as well but is more difficult to find commercially today; they were common in the drafting instrument sets of my youth.

Attachment 50317

Your craftsmanship and attention to detail are very worthy of admiration. You have done a superb job, well done.

Totally gorgeous!
And a great idea!

Wow!! Marvelous work. Bravo.