wrote in message
...
On Sat, 17 Dec 2011 12:39:45 -0500, "Jim Wilkins"
...
As I see another one of these in the near future followed closely by a
need to cut 3/4-16 I shall have a go. I suspect the whole thing will
be done manually as I have no confidence of my ability to stop the
lathe at a speed of 150 rpm just at the right moment...
Michael Koblic,

Mine turns at about 50 RPM in back gear and still demands close attention
and quick reactions to stop at the end of the thread. I shut off the motor
when it's about one thread away and then lift the belt tension lever to stop
the spindle quickly.

The spindle is fairly easy to turn by hand if the bit is sharp and the chip
1-3 thousandths thick. It's certainly less effort than cutting the full
depth thread all at once with a die. Could you make up a safe balanced hand
crank for the spindle and use the power only to run the bit back to the
start?

jsw