yourname wrote:

Now wait, you can use the thread dial with odd pitch threads[3 1/2 for
instance], as long as you always return to the same number, it makes
no sense to me that metric would be any different.
Second, if you could not do that, could you not put witness marks on
the leadscrew, chuck, and set an indicator or stop on the back of
the carriage, and it would HAVe to be in the same spot, no?

Stan-O wrote:

Tim, one note that you might want to remember on your lathe, it will
make you life easier.

Even though you do not have a thread chasing dial, you can still
dissengage on threds that are a multiple of the leadscrew.

For example if your lathe has 4 TPI, you can thread
4,8,12,16,20,24,28,32 etc and disengage because the lathe will follow
the same path every time you fully engage the half nut.

Your lather probably has 6 or 8 TPI leadscrew so you can figure out
multiples and save you self some time and grief.

-S


What I did when I wanted to cut a "inch" thread on a metric lathe. I
engaged the half nut
with the dial set to zero. At the end of the first pass I disengaged the
half nut, backed out
the cutter and stopped the lathe. I then reversed the lathe and when the
dial again read zero
I engaged the half nut and continued to run the lathe in revers until it
was ready for the next pass.

It was tricky but worked.

Bill K7NOM