08-17-2014, 08:00 AM
I would also have to run the threads without disengaging the half nut. Any lathe with an "inch" lead screw has that problem.
You don't need tools like those I have, they're hard to find and can be expensive. I just happened to get one for free and the other on eBay for "pennies on the dollar".
Being brass it's easier to just mount a HSS or brazed carbide threading tool upside down. The tricky part is in the retracting. You would have to be able to run the carriage back (perhaps under power) but then "inch" it forward until the tool can just be brought down into the thread relief groove at the shoulder.
Brass is the best material for that because it rarely galls. The cheaper lens filters and other attachments now made of aluminum do tend to cross-thread and gall together. The best filters (B+W, Heliopan, Nikon) all seem to have blackened brass construction.
You don't need tools like those I have, they're hard to find and can be expensive. I just happened to get one for free and the other on eBay for "pennies on the dollar".
Being brass it's easier to just mount a HSS or brazed carbide threading tool upside down. The tricky part is in the retracting. You would have to be able to run the carriage back (perhaps under power) but then "inch" it forward until the tool can just be brought down into the thread relief groove at the shoulder.
Brass is the best material for that because it rarely galls. The cheaper lens filters and other attachments now made of aluminum do tend to cross-thread and gall together. The best filters (B+W, Heliopan, Nikon) all seem to have blackened brass construction.