On 2010-03-08, Wes wrote:
Ignoramus8009 wrote:

On 2010-03-08, Joseph Gwinn wrote:
Right. One has to wait for the leadscrew to turn to the correct angle for the
nut to engage. One way to do this is to watch the threading dial and operate
the lever only when the dial says it's time. After a little practice this
become a fluid motion.

There is a position in between the lines that will ruin your threading job. DAMHIKT. I
guess it is okay if you are making a two start thread.

I have not done much threading.


The issue is that if I apply any significant force on the half nut
lever, the pin would bend. I just spoke to Clausing, they no longer
have those pins, but can supply drawings for $5. Since replacing them
is such a pain, I should be careful with the one I have now.

To stay safe, I may change the handle on the half nut lever, to
something very tiny that would be very difficult to force. Maybe a 1
inch long handle made of a socket head cap screw. That would be harder
to accidentally force enough to bend the internal pin. It will not
look as great, but it will keep me safe, and I will of course save the
old handle.

What annoys me about my 6903 lathe is the half nuts engage by
pulling up. Every lathe I've ever used worked by pushing down.
Looking at the drawing again makes me wonder if that is something
easy to change. The mechanism looks the same as on lathes that work
the way I like.

I do not personally object to this.


One good thing that will be a pita at first is cutting feed will
work towards the chuck while screw cutting feed goes the other way.
Most of the time you tend to feed toward the chuck when turning. If
you ever accidently grab the half nuts lever at turning speeds, you
will appreciate the carriage moving away from the chuck.

I have almost completely reinstalled the apron/carriage assy.

Did you take pictures? Do you have to remove the lead screw to get the apron off?

Some pictures are here.

http://igor.chudov.com/projects/Clausing-6913-Lathe/

I painted the front of the lathe, with epoxy cold galv primer and
epoxy paint. I am not very happy with the resulting appearance (paint
"ran" in a few places), but I am sure that it will provide rock solid
protection. This epoxy is very hard and tough.

I have not taken pictures of the lathe reassembled and repainted, yet,
but I may do so tomorrow. Also note that I only painted the front side
of the lathe, because it was easier to do with the apron and leadscrew
taken off.

Back to your question about the leadscrew, yes, I removed it with the
apron. I took it off and wirebrushed clean, as it was completely
clogged with crud and resisted any other form of cleaning.

I've only pulled the apron off of one lathe. A big Dajung and it
took me and another guy to lift it. Chips embedded in the half nuts
was that machine's problem. I had to pull the screw on that one.

I did that by myself, it was not that big, maybe 90 lbs with the
leadscrew.

i