A couple of weeks ago, I asked if any of you could reccommend a tube
bender for a project I have been working on. I think it was Paul that
suggested Wagner in Milwaukee. Well, I picked up the bent tube yesterday
and they did a nice job. My cost was about $400USD for 15 pcs (2 bends
each). Not to bad, and I will be able to polish,do my magic and ship on
Friday. Right on time!!!

Thanks to all who made suggestions

Next.

I posted a couple of months ago about my little Atlas/Craftsman lathe
that my FIL gave me. I've been playing with it and I discovered that I
have a runout of about .008-.009" with the chuck on. At the spindle I
have about .0005" (1/2 a thoushandth) at the spindle. It first, I
thought that I might have bad bearings on the spindle, but .0005" seems
pretty good, so most of the runout must be in the 3 jaw. Any suggestions
to get rid of the runout?

Greg

Greg Postma wrote:

I posted a couple of months ago about my little Atlas/Craftsman lathe
that my FIL gave me. I've been playing with it and I discovered that I
have a runout of about .008-.009" with the chuck on. At the spindle I
have about .0005" (1/2 a thoushandth) at the spindle. It first, I
thought that I might have bad bearings on the spindle, but .0005" seems
pretty good, so most of the runout must be in the 3 jaw. Any suggestions
to get rid of the runout?

First, take it off the lathe and take it over to the bench. Completely
disassemble it. Get the worm out in your hand. Clean it immaculately, and clean
in there behind it. Then put it back on, and take out your feeler gages and
check the clearance between the center of the worm and the central boss. If
there is more than .001" there you have wear which can be taken up by carefully
placing one shim so it goes all around the central boss. Finally, clean the jaws
immaculately, then reassemble and test. Should get you to .003" or so -- that's
what you get with a 3-jaw. There are ways to make any 3-jaw into an "ajust-tru"
but it's quite a bit of work. Every 3-jaw needs tearing down every so often for
a good cleaning.

GWE

Grant Erwin wrote:


First, take it off the lathe and take it over to the bench. Completely
disassemble it. Get the worm out in your hand. Clean it immaculately,
and clean in there behind it. Then put it back on, and take out your
feeler gages and check the clearance between the center of the worm and
the central boss. If there is more than .001" there you have wear which
can be taken up by carefully placing one shim so it goes all around the
central boss. Finally, clean the jaws immaculately, then reassemble and
test. Should get you to .003" or so -- that's what you get with a 3-jaw.
There are ways to make any 3-jaw into an "ajust-tru" but it's quite a
bit of work. Every 3-jaw needs tearing down every so often for a good
cleaning.


Thanks Grant
I thought it might be built up spoog or gungus crud or something, but I
really didn't want to tear the thing apart if it didn't need to. Tonight
I might see if I can get the thing apart and cleaned.

What would be a good lube when I reassemble the chuck?

Thanks
Greg

Greg Postma wrote:

What would be a good lube when I reassemble the chuck?

Here's a post I archived some time ago:

"My choice (for lubricating lathe chucks) is Dow Corning G-N Metal Assembly
Paste. It is a light bodied grease loaded with moly, graphite and other solid
lubes. A very thin film on the scroll and other friction surfaces makes for a
very smooth action that lasts a long time. All chucks eventually have to be
taken apart to remove chips, but the thin lube film causes minimal build up."

Sometime I'll get some of that stuff, for now I've just been using lithium grease.

GWE

Grant Erwin wrote:


Sometime I'll get some of that stuff, for now I've just been using
lithium grease.

GWE

I got somma that!!!
Thank Grant

Greg

"Greg Postma" wrote in message
...
A couple of weeks ago, I asked if any of you could reccommend a tube
bender for a project I have been working on. I think it was Paul that
suggested Wagner in Milwaukee. Well, I picked up the bent tube yesterday
and they did a nice job. My cost was about $400USD for 15 pcs (2 bends
each). Not to bad, and I will be able to polish,do my magic and ship on
Friday. Right on time!!!

Thanks to all who made suggestions

Next.

I posted a couple of months ago about my little Atlas/Craftsman lathe
that my FIL gave me. I've been playing with it and I discovered that I
have a runout of about .008-.009" with the chuck on. At the spindle I
have about .0005" (1/2 a thoushandth) at the spindle. It first, I
thought that I might have bad bearings on the spindle, but .0005" seems
pretty good, so most of the runout must be in the 3 jaw. Any suggestions
to get rid of the runout?

Greg

Grant's information is good, but before you jump through several hoops, you
might want to clarify what you said. I gather that you have only .0005"
near the spindle, but a distance from the chuck it's more----the .008"/.009"
you mentioned. If that be the case, you could have a sprung chuck, which
is very likely on such a small one. Often times a short piece is chucked
at the very ends of the jaws, then over tightened. The stress permanently
deforms the chuck slides, causing the jaws to grip only at the rear. It's a
major source of chatter and runout on long objects.

Check the jaws by inserting something hard and ground----an end mill shank,
for example, or a drill blanks if you have them. You want this item deep
in the chuck, so the jaws grip at the very back, or inside the chuck body.
Snug up the jaws (lightly, don't get down on the wrench), then see if you
can insert a feeler gauge between the jaws and the chucked item at the
outside end. If you can, the chuck is sprung. It can be salvaged by
grinding the jaws, which we can talk about if you find that's the problem.

Harold

Check the jaws by inserting something hard and ground----an end mill
shank,
for example, or a drill blanks if you have them. You want this item deep
in the chuck, so the jaws grip at the very back, or inside the chuck body.
Snug up the jaws (lightly, don't get down on the wrench), then see if you
can insert a feeler gauge between the jaws and the chucked item at the
outside end. If you can, the chuck is sprung. It can be salvaged by
grinding the jaws, which we can talk about if you find that's the problem.


FWIW, after getting your chuck clean make up a fixtrue like so:
http://lathe.com/tips/chuck-jaw.htm (Scott Logan's web site)
Then use a carbide boring bar to just shave a RCH off each of the jaw ends.
Everything ends up square and right on center at that diameter.

Karl

On Wed, 14 Sep 2005 17:13:25 -0500, Greg Postma
wrote:

A couple of weeks ago, I asked if any of you could reccommend a tube
bender for a project I have been working on. I think it was Paul that
suggested Wagner in Milwaukee. Well, I picked up the bent tube yesterday
and they did a nice job. My cost was about $400USD for 15 pcs (2 bends
each). Not to bad, and I will be able to polish,do my magic and ship on
Friday. Right on time!!!

Thanks to all who made suggestions

Next.

I posted a couple of months ago about my little Atlas/Craftsman lathe
that my FIL gave me. I've been playing with it and I discovered that I
have a runout of about .008-.009" with the chuck on. At the spindle I
have about .0005" (1/2 a thoushandth) at the spindle. It first, I
thought that I might have bad bearings on the spindle, but .0005" seems
pretty good, so most of the runout must be in the 3 jaw. Any suggestions
to get rid of the runout?

Greg

Replace the chuck. Though to be fair..thats about normal for a worn
chuck of that vintage.

Gunner

"Pax Americana is a philosophy. Hardly an empire.
Making sure other people play nice and dont kill each other (and us)
off in job lots is hardly empire building, particularly when you give
them self determination under "play nice" rules.

Think of it as having your older brother knock the **** out of you
for torturing the cat." Gunner

"Karl Townsend" remove .NOT to reply wrote
in message link.net...


Check the jaws by inserting something hard and ground----an end mill
shank,
for example, or a drill blanks if you have them. You want this item
deep
in the chuck, so the jaws grip at the very back, or inside the chuck
body.
Snug up the jaws (lightly, don't get down on the wrench), then see if
you
can insert a feeler gauge between the jaws and the chucked item at the
outside end. If you can, the chuck is sprung. It can be salvaged by
grinding the jaws, which we can talk about if you find that's the
problem.


FWIW, after getting your chuck clean make up a fixtrue like so:
http://lathe.com/tips/chuck-jaw.htm (Scott Logan's web site)
Then use a carbide boring bar to just shave a RCH off each of the jaw
ends.
Everything ends up square and right on center at that diameter.

Karl


Is that a metric or Imperial measure?