> Nice! Thanks. The one I'm working on at the moment is the one with the open-frame gears. Decided that cutting and polishing well- matched involute teeth in thick end-grain hardwood is not how I want to spend my day (after day after day) so I'm going to spend some time at a 3D printing club. Plan is to print a set of teeth rings that can be used to make silicone moulds for epoxy or polyester. The clock will still be overwhelmingly wood, it'll just have resin inserts. I think it's a reasonable compromise. They'll look better, run better, wear better, and it's much more economic (bugger integrity !!) > Ever run across one of these? >=20 > http://en.wikipedia.org/wiki/Synchronome I've seen an article about a super-accurate lab clock with a pendulum in a vacuum, so it's probably that one although I didn't remember the name There are horologists who spend waaaaaaaaaaaaay more time than I do on some very elaborate mechanisms. I'm not devoted to any particular past-time, I dabble all over the place Joe --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .