Jim,
Well, it seems I once again mixed up time periods of tumblers when I referred to a bearing step. Sorry about that and thanks for setting me straight.
For some reason, search engines and me do not get along real well and I’m sure it is something I do not understand about them. However, I was finally able to find the thread on scratch built locks you mentioned to look at the disassembled view of your tumbler grinder and your description of how you made it. VERY interesting. I have JHAT I-IV and though I have read them all four or five times, it looks like I will be reading them again.
With your abilities, which I sincerely admire, you are in the camp of making a part to fit while I am still in the camp of using replacement parts and then fitting them. I have to remind myself of that when I’m asking questions. Grin. I am groping a little here, so I hope you will pardon me. So at the 18th century faires or reenactments, are you making tumblers from ones you already roughed out or using your grinder to fit factory or “store bought” replacement tumblers? I realize if you are working original locks or repro locks where the parts are not available, you would be making the parts. So maybe a better way of asking would be are you also using the grinder to fit factory parts from say Pedersoli or the more recent repros from India?
Since parts for the Jap Besses have not been available for some years, I’ve been thinking about borrowing another Jap Bess, if one does not come in soon for repair, to measure the parts, make a poor man’s blueprint of them, and make some replacement parts. Of course, I can not make the springs, so I’m out of luck there and will have to see if I can modify other springs to use in them.
I REALLY appreciate you sharing all this great information.
Gus