I got at auction a Clausing 5900 12x24. In setting up a chuck I found
..0025 radial runout on the nose taper. The spec is less than .0005. Is
there any kind of bearing problem that will cause this? The runout is at
the same position every rev. The bearings appear to be as tight as they
will go. Thanks Paul

In article ,
Paul Weber wrote:
I got at auction a Clausing 5900 12x24. In setting up a chuck I found
.0025 radial runout on the nose taper. The spec is less than .0005. Is
there any kind of bearing problem that will cause this? The runout is at
the same position every rev. The bearings appear to be as tight as they
will go. Thanks Paul

Is it the same on the inside taper?

I suspect that what happened is that someone managed to spin a
bearing at the nose end of the spindle, and did a knurling job to expand
what was left to grip the replacement bearing -- and did the job
somewhat unevenly. I've found light knurling on my L-00 spindle when I
swapped it in to replace a 2-1/4x8 spindle (mine was a model 5418, and I
wanted the better spindle nose. But mine came out pretty good, in spite
of the knurling.

Good Luck,
DoN.

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The runout is the same on the inside taper, over .002.
So much for buying old American iron.
Paul


"DoN. Nichols" wrote in message
...
In article ,
Paul Weber wrote:
I got at auction a Clausing 5900 12x24. In setting up a chuck I found
.0025 radial runout on the nose taper. The spec is less than .0005. Is
there any kind of bearing problem that will cause this? The runout is at
the same position every rev. The bearings appear to be as tight as they
will go. Thanks Paul

Is it the same on the inside taper?

I suspect that what happened is that someone managed to spin a
bearing at the nose end of the spindle, and did a knurling job to expand
what was left to grip the replacement bearing -- and did the job
somewhat unevenly. I've found light knurling on my L-00 spindle when I
swapped it in to replace a 2-1/4x8 spindle (mine was a model 5418, and I
wanted the better spindle nose. But mine came out pretty good, in spite
of the knurling.

Good Luck,
DoN.

--
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

Paul Weber wrote:

The runout is the same on the inside taper, over .002.
So much for buying old American iron.


Well, you can pull it apart and check for any obvious signs
of improper repairs, damaged parts, etc. Check the bearings to make
sure they are not damaged (it may not take a badly dented roller or inner
race to produce the symptoms you describe. When you get the spindle
out, you can try rolling it on a surface plate to look for actual bending.
If the bending is obvious, you can check around to see who can make
a new spindle for you. A very servicable spindle is not that hard to make,
especially if you can get access to a toolpost grinder. Make a spindle
"blank", in other words, don't finish the inside taper or the chuck mounting
threads until the spindle is back in YOUR lathe headstock. You can cut
the inside taper with the compound slide. You use a known-good male
taper as a master, and use blue dye to check the fit. When you get even
marking of the blue dye, the angle of the compound is exactly right, then
grind a little at a time until the arbor goes to the correct depth.

Cutting the taper for the chuck is easier, and you just test fit the chuck
until it threads on smoothly.

If the bend in the spindle is only at the outer tip, you can just reface the
backplates of all your chucks, and regrind the inside taper until it
runs true.

Jon

In article ,
Jon Elson wrote:


Paul Weber wrote:

The runout is the same on the inside taper, over .002.
So much for buying old American iron.


Well, you can pull it apart and check for any obvious signs
of improper repairs, damaged parts, etc. Check the bearings to make
sure they are not damaged (it may not take a badly dented roller or inner
race to produce the symptoms you describe. When you get the spindle
out, you can try rolling it on a surface plate to look for actual bending.
If the bending is obvious, you can check around to see who can make
a new spindle for you.

Or pick up one from eBay -- perhaps with a spare headstock
wrapped around it. That's how I converted my 5418 (2-1/4x8 thread) to
L-00. Or go to the Daves (Dave Sobel and Dave Ficken) to see if one of
them can find one for you.

A very servicable spindle is not that hard to make,
especially if you can get access to a toolpost grinder. Make a spindle
"blank", in other words, don't finish the inside taper or the chuck mounting
threads

No threads on this one, just another taper with a keyway
machined in it, and a key installed. (I believe that he has a L-00
spindle nose on this machine.)

until the spindle is back in YOUR lathe headstock. You can cut
the inside taper with the compound slide. You use a known-good male
taper as a master,

The internal taper is MT 4-1/2, for which it is more difficult
to find the masters. (It was actually a ASA taper, where they took the
Morse series, and put them between two other series, plus added the
4-1/2 taper to fill a perceived gap. I think that is the smallest of
these tapers which will handle a 5C drawbar and nosepiece, not forcing
you to go to the bulk of MT-5 for the size needed.)

and use blue dye to check the fit. When you get even
marking of the blue dye, the angle of the compound is exactly right, then
grind a little at a time until the arbor goes to the correct depth.

Cutting the taper for the chuck is easier, and you just test fit the chuck
until it threads on smoothly.

Or slides on smoothly, since it is another taper. Once that
fits (checked with bluing) then pull the spindle and mill the key slot
and install the key.

If the bend in the spindle is only at the outer tip, you can just reface the
backplates of all your chucks, and regrind the inside taper until it
runs true.

I think not a good idea with the L-00 spindle nose, though it
could work on a threaded spindle nose.

Enjoy,
DoN.
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Hi Paul;

The first question I would have is this does the issue, that is the
excessive radial runout, occur if you take your measurements from
different positions around the spindle? Also do you get a corresponding
axial runout when the defective area passes by? My first thought is that
a bent spindle is unlikely, it could very well be bad bearings. I've
seen amny of a lathe that has failed due to poor lubrication of the
spindle bearings. While I'm not familiar with the clausing, I have seen
plugged oil lines and lack of maintenance attention cause these sorts of
things.

The bearings may be tight but that does not imply that they are any good.
Also on large spindles your really need to use a dial indicator to check
the tightness of the spindle bearings. As far as a bearing problem if
you should have a bit of galling on one of the bearing races that will
cause the problem.

I suppose that the spindle could have been bent, though to be honest I've
seen little of this. To check the spindle you would have to remove it
from the machine and check it out with some inspection equipment. This
is likely to be a lot of work but if your looking at the bearings it will
be silly not to have it checked out. If the front bearing has turned
like many have suggested, then you may need to look into the purchase of a
new spindle. Refurbishment of the old spindle is always possible, but do
not consider any rebuilder who does not have a history of rebuilding machine
spindles.

Since the spindle is a key component of a lathe you will want this right.
Frankly this issue severly limits what you can use the lathe for. Lots
of luck.

Thanks
Dave


On Wed, 20 Aug 2003 02:34:11 +0000, Paul Weber wrote:

I got at auction a Clausing 5900 12x24. In setting up a chuck I found
.0025 radial runout on the nose taper. The spec is less than .0005. Is
there any kind of bearing problem that will cause this? The runout is at
the same position every rev. The bearings appear to be as tight as they
will go. Thanks Paul



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In article , David A. Frantz says...

I suppose that the spindle could have been bent, though to be honest I've
seen little of this. To check the spindle you would have to remove it
from the machine and check it out with some inspection equipment. This
is likely to be a lot of work but if your looking at the bearings it will
be silly not to have it checked out. If the front bearing has turned
like many have suggested, then you may need to look into the purchase of a
new spindle. Refurbishment of the old spindle is always possible, but do
not consider any rebuilder who does not have a history of rebuilding machine
spindles.

I would think that if the spindle itself were bend, the bearings
would bind badly at some point in the rotation. The fact that
it does not, implies it is either a wear issue on the nose of
the spindle, or a bearing issue.

Jim

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please reply to:
JRR(zero) at yktvmv (dot) vnet (dot) ibm (dot) com
==================================================

Paul:

I have a 14" Rockwell. It has a L00 spindle like yours. One thing I noticed
about the lathe when I first got it was that changing old worn chucks required
alot of fiddling to get the runout where it needs to be. My Rockwell chuck
have Buck mounting plates with L00. The lathe came from a school, and the kids
evidently did not believe in cleaning the spindle L00 nose before changing
chucks. If you have a .0005 or .0001 test indicator, check the inside nose
surface, mark the high and low points. Then do the same on the outside nose
surface. If the highs and lows concide, then it may well be bent. If not,
then probably the nose surface is worn. You can then do 2 things: Wiggle the
chuck when you mount it to see if you can compensate for the worn nose area OR
remove the spindle, metalspray the nose and have it reground. Much cheaper
than making a whole new spindle.

Maxaggie

"Paul Weber" wrote in message ...
I got at auction a Clausing 5900 12x24. In setting up a chuck I found
.0025 radial runout on the nose taper. The spec is less than .0005. Is
there any kind of bearing problem that will cause this? The runout is at
the same position every rev. The bearings appear to be as tight as they
will go. Thanks Paul


I tend to approach these scenarios a bit differently. Most folks seem
to take their readings as gospel right off the bat. One thing I've
learned is that getting a good read on an indicator is very difficult.
I would never tear something apart until I analyzed the data at hand
six ways from Sunday. I wrote a small article titled "The potential
Folly Of indicators" that addresses this issue. There is always time
to tear something apart, but be mindful of the old axiom "If it ain't
broke, don't fix it!"
Right off the bat, I'd want to know if you are truely reading runout,
or surface irregularities on the spindle. One example: The LOO spindle
employs a key on a long spindle taper (the "L" in LOO stand for long).
There is only one position where the chuck will mount. This leaves a
virtually untouched portion of the spindle where the backplate has a
keyway cutout. The rest of the spindle gets its share of battle scars
over the years. This can cause the spindle to appear out of round. In
this case, it is, but the backplate never contacts the portion that is
reading high.
A similar reading on the internal taper that coincides with the same
position on the outer taper may rule this out as the culprit.
Small surface irregularities certainly read differently on an
indicator than runout. To get an idea of how runout reads, you can
chuck something up in a 4 jaw chuck slightly off center and observe
the dial movement.

I guess my point is never start with the assumption that your data is
beyond reproach. Rule out human error as a possibility before assuming
a mechanical error.

Good Luck.
Dave Ficken
Meridian Machinery
http://www.mermac.com

Coming soon:
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