On Thu, 8 Mar 2012 18:14:10 -0500, Jim Wilkins wrote:


"Bob S" wrote in message
...
I guess there are lots of way to do this. The only tricky part seems
to be drilling a fairly small hole down two inches of rod, and I
suppose that is straightforward on a lathe.
Bob

Could you mount a handwheel behind the chuck? You can't spin it fast
but a larger wheel will have more torque to drive a threading cut.

Well, I suppose that I could turn a disk with spindle and chuck
mounting features fore and aft, and holes for the chuck screws, and
get some longer screws and attach the chuck through the plate.
The handwheel could only be about four inches in diameter to clear the
bed, and only about half of the circumference would be reachable, and
grabbing it would be awkward so close to the chuck, and it couldn't be
installed and removed without re-mounting the chuck. Maybe I am not
visualizing what you are thinking of; it sounds awkward.



I just pull on the chuck (or the leather drive belt) to finish a
threading cut at a definite stopping point.

Before you start, can you easily disconnect the spindle from the
motor? There may not be much point in this if you can't and have to
fight the drivetrain drag..

I could slip off one of the drive belts.

But turning the motor by hand is not difficult on a machine this
small.



Some of us have old industrial lathes with somewhat different controls
from yours:
http://www.practicalmachinist.com/vb...y-dsc04198.jpg

The lever on the base declutches the motor drive from the spindle,
making the chuck very easy to turn by hand.

The similar, smaller lever on the right side of the carriage apron
releases the leadscrew so the handwheel to its left can move the
carriage quickly, or hand-feed a cut.

The tailstock base slides sideways for turning tapers between centers.

The compound has a tee slot in the top to hold a separate tool post,
which looks like it's aligned like yours on that lathe.

On the Proxxon lathe the T-slot is on the cross-slide not the compound
slide.


AFAIK yours doesn't have these and suggestions that mention them don't
apply. I've used a Prazi which is like yours, but didn't cut threads
on it because it had a broken plastic gear. .

jsw



Bob