"Grant Erwin" wrote in message
...
There is a good article in the latest "Home Shop Machinist", available now
in good bookstores, on a device to automatically disengage the half nuts
at the end of threading. It's very clever, but I don't know if it will
work on a South Bend. The exact reference is:
"An Automatic Carriage Stop for Thread Cutting" by James McKee M/J 05 HSM
If you want something that will prevent power-crashing the carriage into
the chuck when powerfeeding, then you need a limit switch setup, perhaps
backed up with a solid beefy carriage stop. I don't know where plans for
a limit switch setup are.
My 1938 F.E. Reed has such a feature. One uses a split collar around the
feed drive rod as the stop. When the carriage finally bumps the collar, it
moves the feed rod left, disengaging a spline clutch. [and it doesn't work
using the threading lead screw !

]
LLoyd