You're welcome PK. I can't tell you how many times I've looked at that photograph -- copied off the internet 15 years ago -- I don't remember where. It took a long time to figure out what was what. I'm still tempted to add it to my old Gingery lathe.

But for now, working on the new lathe.

And Norman(s) here's one more possible method for thread cutting without change gears... uh I guess you'd call it the pantograph method:
Slightly more information here:
http://www.jacquesmaurel.com/machiningI found a copy of the referenced Model Engineer (4270, April 2006) on ebay and sent for it. But it will apparently be two weeks or more getting here from UK shores. I'd appreciate it if someone could send me a copy of the article before that. -- though I had worked out and tested an electronic change gear system for my new lathe, I think I would prefer the mechanical simplification of something like this. Plus I think it's really cool.

Norman (Fergus) sounds like a good use of time to me!

Norman (lathe builder) Yes indeedy, that boring method is familiar -- bored my Gingery headstock and tailstock that way, and will do it again on the new lathe. With the weird reversal that I already have a tailstock bore and will use that to bore the headstock. Either way, they come out the same Z and Y axis position on the ways, parallel and concentric, which is the point!
