If you recall my earlier post, the apron interlock pin was bent in my
lathe, and after straightening it out, it would not properly engage
with the lock arm. I thought that maybe I did not do a good job
straightening it, etc.

Finally I guessed that the root cause of it was 1) bending of the pin
by some unthinking user when it was intelocked and 2) the cam on the
half nut shaft not being seated where it should be. So the travel
range of the interlock arm was wrong.

After checking this guess, it turned out to be correct. After turning
the cam a bit (loosening the setscrew etc) the range of travel of the
lock arm is now correct, and the interlock system is working. I can
now see that this pin is very fragile. The bottom line is that I can
only operate the half nut lever very gently, with my pinky finger, and
never apply any force to it.

The apron seems to work completely properly and I am reinstalling it,
along with the cleaned leadscrew, etc.

i

In article ,
Ignoramus10008 wrote:

If you recall my earlier post, the apron interlock pin was bent in my
lathe, and after straightening it out, it would not properly engage
with the lock arm. I thought that maybe I did not do a good job
straightening it, etc.

Finally I guessed that the root cause of it was 1) bending of the pin
by some unthinking user when it was intelocked and 2) the cam on the
half nut shaft not being seated where it should be. So the travel
range of the interlock arm was wrong.

After checking this guess, it turned out to be correct. After turning
the cam a bit (loosening the setscrew etc) the range of travel of the
lock arm is now correct, and the interlock system is working. I can
now see that this pin is very fragile. The bottom line is that I can
only operate the half nut lever very gently, with my pinky finger, and
never apply any force to it.

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.

Joe Gwinn

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.

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.

I have almost completely reinstalled the apron/carriage assy.

i

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.


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.

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?

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.

Wes

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

Ignoramus8009 wrote:

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.


Neither have I. About 50 times so far over the years. For sure less than a hundred
single pointing. I have a few things to make that will up that count a bit quickly.


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.

Unless you have muscle memory involved in this, anything would be okay fine for you. I
keep worrying that my conditioning will make me do the wrong thing at home or at work.


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/

Sweet. I don't remember seeing these. Is this part of reorganizing?

When you get done with this, I'll add a link to your project page. If you google
"clausing 6903" I pop up on top. Damn, I'm famous


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.

My paint job is a bit nasty. Guy that sold me the lathe told me the ways are perfect and
the paint is nasty. The ways are perfect and the paint is nasty.



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 get help when pulling chunks of metal off of machines.. It doesn't take too much error
in guestimation to get you hurt. I'm trying hard to avoid that magic pop in the spinal
column that changes everything for the worse.

Wes

On 2010-03-09, Wes wrote:
Ignoramus8009 wrote:
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/

Sweet. I don't remember seeing these. Is this part of reorganizing?

When you get done with this, I'll add a link to your project page. If you google
"clausing 6903" I pop up on top. Damn, I'm famous

Awesome. Great SEO job. I am number one for "algebra" and also my
trailer is number one for "homemade trailer" image search. I will
definitely appreciate a link and I can reciprocate with a link to some
other page of your site.


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.

My paint job is a bit nasty. Guy that sold me the lathe told me the
ways are perfect and the paint is nasty. The ways are perfect and
the paint is nasty.

In my case, the paint looks not so good, but functionally I expect it
to provide years of excellent protection.


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

I get help when pulling chunks of metal off of machines.. It doesn't take too much error
in guestimation to get you hurt. I'm trying hard to avoid that magic pop in the spinal
column that changes everything for the worse.

I just try to lift carefully and not exceed my limits, but yes, I also
worry about this.

i

In article ,
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.

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.

I would leave it alone. The guy that bent the pin was a gorilla - more muscle
than brain.

You will find that it is not at all hard to get the half-nut engaged without
forcing anything. You make the move just before the correct line on the
threading dial goes by. Any you don't force it -- you do it by feel.

Joe Gwinn

On 2010-03-09, Joseph Gwinn wrote:
In article ,
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.

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.

I would leave it alone. The guy that bent the pin was a gorilla - more muscle
than brain.

You will find that it is not at all hard to get the half-nut engaged without
forcing anything. You make the move just before the correct line on the
threading dial goes by. Any you don't force it -- you do it by feel.

What such a small handle would do, is protect me from my own
mistakes. Or, say, if I invite a friend over and he would try to force
the lever, that would not happen if the handle was tiny.

i

On 2010-03-08, Wes wrote:

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


Here are some pictures.

http://igor.chudov.com/projects/Clau...-And-Repaired/

I verified all the functions, and it seems to work just fine.

i

In article ,
Ignoramus8009 wrote:

On 2010-03-09, Joseph Gwinn wrote:
In article ,
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.

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.

I would leave it alone. The guy that bent the pin was a gorilla - more
muscle
than brain.

You will find that it is not at all hard to get the half-nut engaged
without
forcing anything. You make the move just before the correct line on the
threading dial goes by. Any you don't force it -- you do it by feel.

What such a small handle would do, is protect me from my own
mistakes. Or, say, if I invite a friend over and he would try to force
the lever, that would not happen if the handle was tiny.

Developing the feel and the rhythm is critical, and a too-small lever will
interfere with this.

Ignoring the direction in which one moves the lever, pretty much all lathes work
the same way when engaging the half nuts, and Clausings are not exactly made of
tinfoil.

On reflection, what I suspect happened is that as the half-nuts became packed
with chips, it became harder and harder to engage them well enough that they
wouldn't pop out of engagement, so the level of force used rose gradually. What
people were doing is pack layer after layer of chips into the threads, until no
more chips would fit.

How hard would it be to disassemble and clean only the half-nut assembly? I may
do this on my 5914. Even though I have not had any problem engaging and
disengaging the half nut, and the interlock works, I'm suspicious that there may
be some chip packing because I did find a lot of chip packing under the saddle,
and because the leadscrew was not exactly clean.


Joe Gwinn

On 2010-03-09, Joseph Gwinn wrote:
In article ,
Ignoramus8009 wrote:

On 2010-03-09, Joseph Gwinn wrote:
In article ,
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.

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.

I would leave it alone. The guy that bent the pin was a gorilla - more
muscle
than brain.

You will find that it is not at all hard to get the half-nut engaged
without
forcing anything. You make the move just before the correct line on the
threading dial goes by. Any you don't force it -- you do it by feel.

What such a small handle would do, is protect me from my own
mistakes. Or, say, if I invite a friend over and he would try to force
the lever, that would not happen if the handle was tiny.

Developing the feel and the rhythm is critical, and a too-small lever will
interfere with this.

Ignoring the direction in which one moves the lever, pretty much all lathes work
the same way when engaging the half nuts, and Clausings are not exactly made of
tinfoil.

On reflection, what I suspect happened is that as the half-nuts became packed
with chips, it became harder and harder to engage them well enough that they
wouldn't pop out of engagement, so the level of force used rose gradually. What
people were doing is pack layer after layer of chips into the threads, until no
more chips would fit.

How hard would it be to disassemble and clean only the half-nut assembly? I may
do this on my 5914. Even though I have not had any problem engaging and
disengaging the half nut, and the interlock works, I'm suspicious that there may
be some chip packing because I did find a lot of chip packing under the saddle,
and because the leadscrew was not exactly clean.


Joe Gwinn

I would estimate that if you go slow, on my lathe it takes 1 hour
to take apron off and one hour to put it back.

New half nuts are only $100 from Clausing, I would say it is a no
brainer to get them when they are still available.

With the apron and leadscrew off, you can take your time to clean the
leadscrew, etc.

i

In article ,
Ignoramus17831 wrote:

On 2010-03-09, Joseph Gwinn wrote:
In article ,
Ignoramus8009 wrote:

On 2010-03-09, Joseph Gwinn wrote:
In article ,
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.

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.

I would leave it alone. The guy that bent the pin was a gorilla - more
muscle
than brain.

You will find that it is not at all hard to get the half-nut engaged
without
forcing anything. You make the move just before the correct line on the
threading dial goes by. Any you don't force it -- you do it by feel.

What such a small handle would do, is protect me from my own
mistakes. Or, say, if I invite a friend over and he would try to force
the lever, that would not happen if the handle was tiny.

Developing the feel and the rhythm is critical, and a too-small lever will
interfere with this.

Ignoring the direction in which one moves the lever, pretty much all lathes
work
the same way when engaging the half nuts, and Clausings are not exactly
made of
tinfoil.

On reflection, what I suspect happened is that as the half-nuts became
packed
with chips, it became harder and harder to engage them well enough that
they
wouldn't pop out of engagement, so the level of force used rose gradually.
What
people were doing is pack layer after layer of chips into the threads,
until no
more chips would fit.

How hard would it be to disassemble and clean only the half-nut assembly?
I may
do this on my 5914. Even though I have not had any problem engaging and
disengaging the half nut, and the interlock works, I'm suspicious that
there may
be some chip packing because I did find a lot of chip packing under the
saddle,
and because the leadscrew was not exactly clean.


Joe Gwinn

I would estimate that if you go slow, on my lathe it takes 1 hour
to take apron off and one hour to put it back.

That's not that bad, although apron removal is required it seems.


New half nuts are only $100 from Clausing, I would say it is a no
brainer to get them when they are still available.

Nor is that.


With the apron and leadscrew off, you can take your time to clean the
leadscrew, etc.

I have already cleaned the leadscrew. Actually, one is supposed to clean it
once a week with kerosene, according to a manual I have.

If I do this repair, I may buy the half nut set in advance, to reduce down time.

As I continue in my educational program to become a machine tool tech.

Joe Gwinn