--- In 7x12minilathe@..., "Ed" <edo@...> wrote:
I tried to cut my first threads, but couldn't get synched up for
additional cuts. I figured out the dial needs to be adjusted to begin
with to even get it to start turning, but it stops turning when I
engage the lead screw nut. Doesn't it need to turn the whole time,
even when I move the tool back to the beginning of the cut? If so, how
do I adjust this thing to keep it turning?
You don't, at least on my Cummins 7x12. This disturbed me at first,
but it doesn't matter.
I haven't done a lot of threading, but what I have done has been
successful (one exception while learning) :-). My dial quits turning
when I engage the half nuts, which isn't a problem.
What you need to know is what marks on the dial are for what thread
(some have multiple number that are right, just use the same one each
time).
Make a very light first cut and check it with a thread gauge. Learned
that the hard way when I got the gear sequence for a metric thread
wrong :-).
Back off the cross slide enough to clear, making sure you note the
setting (I set mine to zero for the first pass, just *barely* touching).
Move the carriage back behind the work.
Move the cross slide back in for the next cut ( adding .002-.003 each
pass, is what I used). Yes, it takes a few passes :-).
Watch the dial and when it gets to the right number for the thread,
re-engage the half nuts. It doesn't matter how far behind the part
you are.
Repeat until you get the desired depth.
After the trepidation of getting the gears set up right, figuring out
the dial and doing the first one, it is pretty easy, just somewhat
tedious. Not afraid of the process any more :)!
Jose's video on the subject went a long way to getting here :-)!
Another option, that I haven't used, is to back off the cross slide
and run the lathe in reverse without disengaging the half nuts until
you get past the end of the part.
It is a *very* nice feeling when you get that first threaded part out
and it works!
Hope this helps!
Take care, Vikki.
