I’ve had some more time to play with the lathe and found a shortcoming I didn’t expect. I mostly do things in metric and am currently working on making some machinist jacks. I used M12x1.75 for the body thread since I have that tap size. When I went to turn the threads on the jack screw, surprise, no 1.75mm thread setting! After a bit of head scratching, I remembered there is a thread chart in Excel on the PM website for this and the 1340GT lathes. I downloaded that and made some tables showing the different combinations of change gears and the threads they will produce. I found I can use an undocumented combination of 32/40 with the transposing gears to give me 1.75mm, it also gives 3.5mm and 0.8mm that are also missing.
Attached is the tables I made for the different combinations, the cells in yellow are the thread pitches that were not exact, but should be close enough. Some of the thread pitches are duplicated with the different gear combinations, I left them in there so that I might not have to change the gears as often if I am doing a variety of thread sizes.
Attached is the tables I made for the different combinations, the cells in yellow are the thread pitches that were not exact, but should be close enough. Some of the thread pitches are duplicated with the different gear combinations, I left them in there so that I might not have to change the gears as often if I am doing a variety of thread sizes.