My clausing lathe cuts tapers instead of straight cylinders.

I am trying to set up my Clausing lathe in a way that eliminates the
possibility that these tapers are caused by anything other than wear
on the lathe (ie, improper leveling, etc)

To that end, I leveled this lathe with a Starrett 98 level.

However, despite that, it still cuts tapers, such as 8/1000 inch per
4 inch of carriage travel. It also produces an uneven finish, which I
would expect to be better. I took some pictures of the finish, which
did not turn out to be good, but I think that you can tell that it is
uneven.

http://igor.chudov.com/projects/Clau...10-Setting-Up/

The surface finish alone could account for quite a bit of diameter
variation.

In short, I want to do everything to align the lathe properly and
produce the best surface possible so that I would only be dealing with
late wear and not any other mistake in turning.

So.

How can I improve the surface finish. This piece that you see in the
chuck is 12L14 steel.

--
Due to extreme spam originating from Google Groups, and their inattention
to spammers, I and many others block all articles originating
from Google Groups. If you want your postings to be seen by
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posting on Usenet.
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Ignoramus3975 writes:

In short, I want to do everything to align the lathe properly and
produce the best surface possible so that I would only be dealing with
late wear and not any other mistake in turning.

So you should test the bearings and the ways for runout and play. Then
test the alignment. Connelly is your friend.

Ignoramus3975 wrote:

My clausing lathe cuts tapers instead of straight cylinders.

I am trying to set up my Clausing lathe in a way that eliminates the
possibility that these tapers are caused by anything other than wear
on the lathe (ie, improper leveling, etc)

To that end, I leveled this lathe with a Starrett 98 level.


Did I see the tailstock supporting the other end of your stock? I don't think so.

Your stock is deflecting. You needed to have a live center in a properly adjusted
tailstock. The LtoD ratio is way wrong. Put a test indicator on the far end, press down
on the stock and see the deflection.


Wes



--
"Additionally as a security officer, I carry a gun to protect
government officials but my life isn't worth protecting at home
in their eyes." Dick Anthony Heller

Ignoramus3975 wrote:


However, despite that, it still cuts tapers, such as 8/1000 inch per
4 inch of carriage travel. It also produces an uneven finish, which I
would expect to be better. I took some pictures of the finish, which
did not turn out to be good, but I think that you can tell that it is
uneven.

Also google follow rest.

Wes

OK. All good points.

My plan is as follows;

1. Replace the three jaw chuck with welded on jaws (something weird)
with a four jaw chuck, which I also have.

2. Somehow, align the tailstock so that it is on center (not yet sure
how).

3. Make one more cut with the four jaw and tailstock.

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to spammers, I and many others block all articles originating
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Ignoramus3975 wrote:

My plan is as follows;

1. Replace the three jaw chuck with welded on jaws (something weird)
with a four jaw chuck, which I also have.

2. Somehow, align the tailstock so that it is on center (not yet sure
how).

3. Make one more cut with the four jaw and tailstock.


Iggy, you want to be turning between centers. A drive plate will have a
taper for a center. Drive the workpiece using a lathe dog.

A quick and dirty check of tailstock alignment is to pinch a flat piece
of metal between the lathe centers. Assuming the centers are properly
ground, the metal should be perpedicular to the ways. If it is not, the
tailstock is misaligned.

Kevin Gallimore


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Wes wrote:
Ignoramus3975 wrote:

My clausing lathe cuts tapers instead of straight cylinders.

I am trying to set up my Clausing lathe in a way that eliminates the
possibility that these tapers are caused by anything other than wear
on the lathe (ie, improper leveling, etc)

To that end, I leveled this lathe with a Starrett 98 level.


Did I see the tailstock supporting the other end of your stock? I
don't think so.

Your stock is deflecting. You needed to have a live center in a
properly adjusted tailstock. The LtoD ratio is way wrong. Put a
test indicator on the far end, press down on the stock and see the
deflection.


Wes
I've got a link somewhere on how to check alignment , when I find it I'll
post . But Wes is right , too much sticking out in relation to the diameter
.. Rule of thumb I learned is no more than two diameters protruding from the
chuck .
--
Snag
'90 Ultra "Strider"
'39 WLDD "Popcycle"
Buncha cars and a truck

If that material is truly 12L14, and that's the surface finish you are
getting close to the chuck, there's a problem.

What DOC, feed and speed were you using?
How did you set the tool height?

I agree with others, you have too much part sticking out, for a
Carbide insert. Would be fine with a high rake, small radius HSS tool
honed sharp for very light cuts.

Google "rollie's dad's method" for an alignment procedure.

I've seen lathes with so much wear near the headstock, it could be
seen with a wood yardstick. Some American Iron is not worth the
trouble.
Dave J.

Terry Coombs wrote:
Wes wrote:
Ignoramus3975 wrote:

My clausing lathe cuts tapers instead of straight cylinders.

I am trying to set up my Clausing lathe in a way that eliminates the
possibility that these tapers are caused by anything other than wear
on the lathe (ie, improper leveling, etc)

To that end, I leveled this lathe with a Starrett 98 level.


Did I see the tailstock supporting the other end of your stock? I
don't think so.

Your stock is deflecting. You needed to have a live center in a
properly adjusted tailstock. The LtoD ratio is way wrong. Put a
test indicator on the far end, press down on the stock and see the
deflection.


Wes
I've got a link somewhere on how to check alignment , when I find it
I'll post . But Wes is right , too much sticking out in relation to
the diameter . Rule of thumb I learned is no more than two diameters
protruding from the chuck .

Here's that alignment link .
http://www.neme-s.org/Rollie's_Dad's_Method.pdf
--
Snag
'90 Ultra "Strider"
'39 WLDD "Popcycle"
Buncha cars and a truck

"Ignoramus3975" wrote in message
...
My clausing lathe cuts tapers instead of straight cylinders.
snip

The way you did that, any lathe would cut a crappy-finished taper. Try a
test with 2" CRS round sticking out 3". Then cut it with HSS with a rake.
Your set-up might just as well be a rubber rod sticking out 15 diameters and
cutting with a butter knife.

Iggy,
There is no half ass way of doing this. Right now you haven't got a clue
what is going on. All of those factors the responders suggested could be the
fault, but you have no way of knowing anything for certain without a test
bar. At the moment, you are chasing your nose. An experienced lathe operator
can out guess the problem, but you do not own those skills. Get a test bar.
Watching you do this is painful to me. I will make you a deal, I think your
spindle nose is a MT 5 taper. Please confirm. If it is, you may borrow my
test bar. I will mail it to you. You use it according to my direction, then
mail it back to me. Contact me off-line to confirm. Just eliminate nospam in
my address.
Steve

"Ignoramus3975" wrote in message
...
My clausing lathe cuts tapers instead of straight cylinders.

I am trying to set up my Clausing lathe in a way that eliminates the
possibility that these tapers are caused by anything other than wear
on the lathe (ie, improper leveling, etc)

To that end, I leveled this lathe with a Starrett 98 level.

However, despite that, it still cuts tapers, such as 8/1000 inch per
4 inch of carriage travel. It also produces an uneven finish, which I
would expect to be better. I took some pictures of the finish, which
did not turn out to be good, but I think that you can tell that it is
uneven.


http://igor.chudov.com/projects/Clau...10-Setting-Up/

The surface finish alone could account for quite a bit of diameter
variation.

In short, I want to do everything to align the lathe properly and
produce the best surface possible so that I would only be dealing with
late wear and not any other mistake in turning.

So.

How can I improve the surface finish. This piece that you see in the
chuck is 12L14 steel.

--
Due to extreme spam originating from Google Groups, and their
inattention
to spammers, I and many others block all articles originating
from Google Groups. If you want your postings to be seen by
more readers you will need to find a different means of
posting on Usenet.
http://improve-usenet.org/

Iggy,

A good place to start might be http://homemetalshopclub.org/news/jan02/jan02.html

I found it and many others by googling "lathe alignment" without the quotes, but it may be
better WITH the quotes.

Hope it helps.

Al

==============

Ignoramus3975 wrote:
My clausing lathe cuts tapers instead of straight cylinders.

I am trying to set up my Clausing lathe in a way that eliminates the
possibility that these tapers are caused by anything other than wear
on the lathe (ie, improper leveling, etc)

To that end, I leveled this lathe with a Starrett 98 level.

However, despite that, it still cuts tapers, such as 8/1000 inch per
4 inch of carriage travel. It also produces an uneven finish, which I
would expect to be better. I took some pictures of the finish, which
did not turn out to be good, but I think that you can tell that it is
uneven.

http://igor.chudov.com/projects/Clau...10-Setting-Up/

The surface finish alone could account for quite a bit of diameter
variation.

In short, I want to do everything to align the lathe properly and
produce the best surface possible so that I would only be dealing with
late wear and not any other mistake in turning.

So.

How can I improve the surface finish. This piece that you see in the
chuck is 12L14 steel.

In article ,
Ignoramus3975 wrote:

My clausing lathe cuts tapers instead of straight cylinders.

I am trying to set up my Clausing lathe in a way that eliminates the
possibility that these tapers are caused by anything other than wear
on the lathe (ie, improper leveling, etc)

To that end, I leveled this lathe with a Starrett 98 level.

Recheck this every few days at first. It will take a while for the iron
to relax into its new configuration.


However, despite that, it still cuts tapers, such as 8/1000 inch per
4 inch of carriage travel. It also produces an uneven finish, which I
would expect to be better. I took some pictures of the finish, which
did not turn out to be good, but I think that you can tell that it is
uneven.

http://igor.chudov.com/projects/Clau...er-Lathe/10-Se
tting-Up/

As others have noted, that bar is far too long and skinny, and
deflection alone would cause a taper cut.

What is the sound as it cuts?

Carbide inserts intended for roughing don't necessarily cut smooth.


The surface finish alone could account for quite a bit of diameter
variation.

It didn't look that way in the photo. Deflection is more likely.


In short, I want to do everything to align the lathe properly and
produce the best surface possible so that I would only be dealing with
late wear and not any other mistake in turning.

So.

How can I improve the surface finish. This piece that you see in the
chuck is 12L14 steel.

I think that you are trying to do too much at once, so there are too
many variables.

I would start with a 1" bar held firmly in a 5C collet, and figure out
how to machine a smooth surface. At that time, you will also be able to
verify that the machine is tight enough.

You remember my 5914 saga - it turned out that multiple things were
wrong, and it required simplification of the setup before I could figure
out what to do. I ended up tightening everything that it was possible
to tighten.

Joe Gwinn

Ignoramus3975 wrote:
My clausing lathe cuts tapers instead of straight cylinders.

So.

How can I improve the surface finish. This piece that you see in the
chuck is 12L14 steel.


Hi Iggy

Looks by the picture that you're using a CNMG332 or 432 tool to cut with
(and the proper insert clamp is missing...). Some notions,

(1) Negative rake tooling requires more horsepower and rigidity than
positive tooling, (use the tailstock and center even if your "soft jaws"
are bored correctly).

(2) The "2" at the end of an insert designation denotes the radius of
the point in 1/64s". Your .032" tool nose wants to be "at least" .032"
depth of cut for the negative rake design of the tool to work properly.

(3) In practicality the best finish for a given radius would be
1/4radius = feedrate, (for a 432 insert that's .032"/4 or .008" per
revolution).

(4) Surface footage is also important and depends on insert design and
composition, machine horsepower, and lastly machine/part rigidity, (most
job shoppers will just determine surface footage by "feel and
experience", use a calculator and do it right, a good start is 300SFPM
if you can).

(5) 12L14 is soft as butter, negative rake tooling actually wants to
shear the material off a slight bit above the business edge (nose) of
the insert (on 1/8" depth of cut the shear starts 1/8" back from the
nose). Any leaded material tends to deform easily and often finishes
poorly with neg rake. Try 1144 (a resulpherized steel) and you'll see a
big difference in finish. *NOTE* it's not wise to weld any leaded or
11XX materials....


You can set the tailstock by turning 2 places on a bar between centers.
I would take a bar some 12" or longer and make a small cut at the
tailstock and 4" to 6" in, measure and adjust, most folks indicate
against the tailstock spindle for reference. Some notions,

(1) a test bar (inserted in the headstock taper) is usefull to align the
headstock with the ways, IE: if you "know" the bed is level and the bar
shows your headstock and saddle are not parallel, then you have to
re-align the headstock. I don't know (can't tell by pics) if your
headstock sits on the flat ways or the "v" ways. Anyway if you re-align
by twisting the bed (for chuck work) you'll have issues with long work.

(2) If you shim on a "v" way for horizontal parallel you can introduce
permenant errors that will show up later, again, with longer work,
(almost everyone shims and lives with it, very few scrape the ways anymore).

(3) The test bar will also help you determine way/saddle wear close to
the headstock, (very common on used lathes, live with it or re-grind or
scrape).

(4) The "98" type levels (at least 10 arc/sec or better) are plenty good
for engine lathe or grinder leveling (they are iffy for turret lathes
which are always aligned with bed twist).

Lastly (I think... too much typing), looks like you have 2 piece soft
jaws which are great but need to be bored for each diameter chucked and
the grip must be as close as possible to the scroll plate as there is
more deflection of the chuck body when you move the grip out (promoting
chuck wear and permanent deformation). Also the "American taper mount"
type chucks move your business farther from the spindle bearings and are
less robust for chuck work.

Matt

On Nov 8, 7:51*pm, Ignoramus3975
wrote:
My clausing lathe cuts tapers instead of straight cylinders....
*http://igor.chudov.com/projects/Clau...36-Master-Lath....

Chuck that piece with about an inch protruding. Turn the end square
with a fairly coarse feed which will mark the center of rotation. Move
the tailstock up to it and check that the point is centered on the
bullseye pattern. If it's way out it could break the drill bit. The
insert's cutting edge has to be at center height for this. File off
any tit it may leave.

Drill a 60 degree center hole in the end and then turn the OD until
the tool cuts all the way around. The accuracy of the chuck doesn't
matter, the cut makes the hole and OD concentric. Zero the crossfeed
dial with the tool holding an old credit card lightly against the
turned OD, like a feeler gauge. The plastic shouldn't chip the insert.

Extend the piece way out, lightly tighten the chuck and run the
tailstock point into the (clean!) center hole. Move the bit to the
turned area and run it in against the credit card again. The crossfeed
dial will show you the tailstock offset, which you can now adjust
nearly to zero.

A dial indicator is better for this if you have one and a way to hold
it. On a worn lathe, watch for increasing play as you crank the
tailstock out and a shift when you tighten the clamp.

Now the lathe should turn a smooth cylinder, at least near the well-
supported ends.

HSS honed to a sharp edge puts less pressure on the work and holds
size better on long flexible shafts like that one. I can shave off
half a thousandth with it.

I save all unembossed dummy credit cards for this, and for padding
rough work in the mill vise.

Good Luck
Jim Wilkins

"Ignoramus3975" wrote in message
...
My clausing lathe cuts tapers instead of straight cylinders.

I am trying to set up my Clausing lathe in a way that eliminates the
possibility that these tapers are caused by anything other than wear
on the lathe (ie, improper leveling, etc)

To that end, I leveled this lathe with a Starrett 98 level.

However, despite that, it still cuts tapers, such as 8/1000 inch per
4 inch of carriage travel. It also produces an uneven finish, which I
would expect to be better. I took some pictures of the finish, which
did not turn out to be good, but I think that you can tell that it is
uneven.


http://igor.chudov.com/projects/Clau...10-Setting-Up/

Try this link to Making a Lathe Test Bar.
http://www.cartertools.com/tgtest.html

I think it will answer any questions you may have.
Roger

"Wes" wrote in message
...
Ignoramus3975 wrote:

My clausing lathe cuts tapers instead of straight cylinders.

I am trying to set up my Clausing lathe in a way that eliminates the
possibility that these tapers are caused by anything other than wear
on the lathe (ie, improper leveling, etc)

To that end, I leveled this lathe with a Starrett 98 level.


Did I see the tailstock supporting the other end of your stock? I don't
think so.

Your stock is deflecting. You needed to have a live center in a properly
adjusted
tailstock. The LtoD ratio is way wrong. Put a test indicator on the far
end, press down
on the stock and see the deflection.


Wes

Wes offered excellent advice, but not for the circumstance at hand. The
use of a center will not disclose the condition of the machine, due to the
influence of the location of the tailstock as it relates to the spindle. If
it has any offset, be it by wear or by having been moved for the purpose of
cutting a taper, you introduce error that may have nothing to do with the
condition of the machine.

In order to determine if your lathe is cutting straight, or not, after it
has been leveled properly, the material you use for the test should be such
that the amount sticking out of the chuck is greater in diameter than 1/3 of
the length of extension from the jaws. That will keep deflection out of
the equation.

You mentioned that the finish you're achieving is uneven. That's a dead
giveaway that your tool is wrong. Leaded steel will cut without skipping or
tearing when you have the geometry right----a statement that can't be made
when machining mild steel. Do not use carbide for this test. Use HSS
with a honed edge, one that has a slight chip breaker ground, which will
increase rake angle. Carbide tends to cut with greater tool pressure, so
it isn't conclusive.

What I'd suggest for the test is a piece of aluminum. 6061-T6 or 7075 T-6
is good, as is 2024-T3 or greater. I strongly suggest the diameter be
fairly large, no less than 1-1/4", to minimize bending of the material under
tool pressure.

Check your jaws to see if the chuck is sprung, which allows the material to
deflect easily. When you chuck a known straight pin, there should be full
contact of the jaws, front to rear. If you find clearance at the outside
edge of the jaws, you can expect material deflection, even with large
diameter material.

Small chucks are often sprung, a function of having been over tightened on
short pieces of material.

How about a report once you've changed a few things?

Harold

On Nov 8, 8:27*pm, Wes wrote:
Ignoramus3975 wrote:
My clausing lathe cuts tapers instead of straight cylinders.

I am trying to set up my Clausing lathe in a way that eliminates the
possibility that these tapers are caused by anything other than wear
on the lathe (ie, improper leveling, etc)

To that end, I leveled this lathe with a Starrett 98 level.

Did I see the tailstock supporting the other end of your stock? I don't think so.

Your stock is deflecting. *You needed to have a live center in *a properly adjusted
tailstock. *The LtoD ratio is way wrong. *Put a test indicator on the far end, press down
on the stock and see the deflection. *

Wes

--
"Additionally as a security officer, I carry a gun to protect
government officials but my life isn't worth protecting at home
in their eyes." *Dick Anthony Heller

Wes, I'm not sure that his tailstock is deflecting, but if his lathe
consistently cuts the same tapers, the tailstock is definitely set
off center. Thats how some of us intentionally cut tapers.

A quick and simple test is to put a dead center in both the headstock
and tailstock, bring them point to point, and using a strong
magnifier, see how closely the points meet. I'm not sure about other
brands, but the tailstocks on Clousing and Atlas lathes have a
tailstock adjustment to do just this.

The key here is that the OP says the tapers are consistent. This
strongly suggests tailstock offset, although there may obviously be
other problems. Still. for consistently tapered cuts, I'd first
eliminate issues that generally trace back to tailstock mis-alignment.

Harry C.

wrote:
On Nov 8, 8:27 pm, Wes wrote:
Ignoramus3975 wrote:
My clausing lathe cuts tapers instead of straight cylinders.

I am trying to set up my Clausing lathe in a way that eliminates the
possibility that these tapers are caused by anything other than wear
on the lathe (ie, improper leveling, etc)

To that end, I leveled this lathe with a Starrett 98 level.

Did I see the tailstock supporting the other end of your stock? I
don't think so.

Your stock is deflecting. You needed to have a live center in a
properly adjusted tailstock. The LtoD ratio is way wrong. Put a test
indicator on the far end, press down on the stock and see the
deflection.

Wes

--
"Additionally as a security officer, I carry a gun to protect
government officials but my life isn't worth protecting at home
in their eyes." Dick Anthony Heller

Wes, I'm not sure that his tailstock is deflecting, but if his lathe
consistently cuts the same tapers, the tailstock is definitely set
off center. Thats how some of us intentionally cut tapers.

A quick and simple test is to put a dead center in both the headstock
and tailstock, bring them point to point, and using a strong
magnifier, see how closely the points meet. I'm not sure about other
brands, but the tailstocks on Clousing and Atlas lathes have a
tailstock adjustment to do just this.

The key here is that the OP says the tapers are consistent. This
strongly suggests tailstock offset, although there may obviously be
other problems. Still. for consistently tapered cuts, I'd first
eliminate issues that generally trace back to tailstock mis-alignment.

Harry C.

Iggy also said nothing about using the tailstock . I was definitely left
with the impression that the far end was unsupported .
--

--
Snag
wannabe machinist

wrote:

Wes, I'm not sure that his tailstock is deflecting, but if his lathe
consistently cuts the same tapers, the tailstock is definitely set
off center. Thats how some of us intentionally cut tapers.


I didn't see a tailstock in use. When I was repairing a hub for my Clausing I
intentionally deflected a tailstock to get a tapered spud to further process the hub.

http://wess.freeshell.org/Boring_new_hub.jpg
http://wess.freeshell.org/mandrill.jpg
http://wess.freeshell.org/clausingdriven640.jpg

I had a thought, most beds are worn near the chuck. Mount an indicator in tail stock on a
long rod held in drill chuck, indicate carriage along the first 10 inches moving tail
stock a corresponding distance as staying over a pickup point. I have a feeling the
tailstock ways are in fair shape at the far end. It should give an idea of how the carrage
is tracking.


Wes

On 2008-11-09, Terry Coombs wrote:
wrote:
On Nov 8, 8:27 pm, Wes wrote:
Ignoramus3975 wrote:
My clausing lathe cuts tapers instead of straight cylinders.

I am trying to set up my Clausing lathe in a way that eliminates the
possibility that these tapers are caused by anything other than wear
on the lathe (ie, improper leveling, etc)

To that end, I leveled this lathe with a Starrett 98 level.

Did I see the tailstock supporting the other end of your stock? I
don't think so.

Your stock is deflecting. You needed to have a live center in a
properly adjusted tailstock. The LtoD ratio is way wrong. Put a test
indicator on the far end, press down on the stock and see the
deflection.

Wes


Wes, I'm not sure that his tailstock is deflecting, but if his lathe
consistently cuts the same tapers, the tailstock is definitely set
off center. Thats how some of us intentionally cut tapers.

A quick and simple test is to put a dead center in both the headstock
and tailstock, bring them point to point, and using a strong
magnifier, see how closely the points meet. I'm not sure about other
brands, but the tailstocks on Clousing and Atlas lathes have a
tailstock adjustment to do just this.

The key here is that the OP says the tapers are consistent. This
strongly suggests tailstock offset, although there may obviously be
other problems. Still. for consistently tapered cuts, I'd first
eliminate issues that generally trace back to tailstock mis-alignment.

Harry C.

Iggy also said nothing about using the tailstock . I was definitely left
with the impression that the far end was unsupported .
--


I left it unsupported, but was making very light cuts.
Anyhow, I will try to center the tailstock, as I have a MT5 dead
center, then I will mount a four jaw chuck and will try cutting a
thicker piece of material with some other cutting tool.
--
Due to extreme spam originating from Google Groups, and their inattention
to spammers, I and many others block all articles originating
from Google Groups. If you want your postings to be seen by
more readers you will need to find a different means of
posting on Usenet.
http://improve-usenet.org/

On 2008-11-09, Harold and Susan Vordos wrote:
Wes offered excellent advice, but not for the circumstance at hand. The
use of a center will not disclose the condition of the machine, due to the
influence of the location of the tailstock as it relates to the spindle. If
it has any offset, be it by wear or by having been moved for the purpose of
cutting a taper, you introduce error that may have nothing to do with the
condition of the machine.

In order to determine if your lathe is cutting straight, or not, after it
has been leveled properly, the material you use for the test should be such
that the amount sticking out of the chuck is greater in diameter than 1/3 of
the length of extension from the jaws. That will keep deflection out of
the equation.

You mentioned that the finish you're achieving is uneven. That's a dead
giveaway that your tool is wrong. Leaded steel will cut without skipping or
tearing when you have the geometry right----a statement that can't be made
when machining mild steel. Do not use carbide for this test. Use HSS
with a honed edge, one that has a slight chip breaker ground, which will
increase rake angle. Carbide tends to cut with greater tool pressure, so
it isn't conclusive.

What I'd suggest for the test is a piece of aluminum. 6061-T6 or 7075 T-6
is good, as is 2024-T3 or greater. I strongly suggest the diameter be
fairly large, no less than 1-1/4", to minimize bending of the material under
tool pressure.

Check your jaws to see if the chuck is sprung, which allows the material to
deflect easily. When you chuck a known straight pin, there should be full
contact of the jaws, front to rear. If you find clearance at the outside
edge of the jaws, you can expect material deflection, even with large
diameter material.

Small chucks are often sprung, a function of having been over tightened on
short pieces of material.

How about a report once you've changed a few things?

I will try again, with a four jaw, bigger bar, and HSS. I will post my
results.

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Ignoramus3975 wrote:
My clausing lathe cuts tapers instead of straight cylinders.

I am trying to set up my Clausing lathe in a way that eliminates the
possibility that these tapers are caused by anything other than wear
on the lathe (ie, improper leveling, etc)

To that end, I leveled this lathe with a Starrett 98 level.

However, despite that, it still cuts tapers, such as 8/1000 inch per
4 inch of carriage travel. It also produces an uneven finish, which I
would expect to be better. I took some pictures of the finish, which
did not turn out to be good, but I think that you can tell that it is
uneven.

http://igor.chudov.com/projects/Clau...10-Setting-Up/

The surface finish alone could account for quite a bit of diameter
variation.

In short, I want to do everything to align the lathe properly and
produce the best surface possible so that I would only be dealing with
late wear and not any other mistake in turning.

How can I improve the surface finish. This piece that you see in the
chuck is 12L14 steel.

Well, the profile of the cutting tool makes a big
difference, and the speed also can affect the
finish. You want to advance the tool as fast as
you can, to avoid work hardening due to recutting
the same area on each turn. Also, a cutting oil
is pretty important to prevent "built-up edge",
where the workpiece material builds up on the
cutting edge and varies the effective tool
position. You get those characteristic rings on
the turned part.

To properly test for taper, you want to mount a
hardened and ground shaft and use a dial test
indicator on the surface. That eliminates almost
all the deflection.

Jon

"Ignoramus3975" wrote in message
...
OK. All good points.

My plan is as follows;

1. Replace the three jaw chuck with welded on jaws (something weird)
with a four jaw chuck, which I also have.

2. Somehow, align the tailstock so that it is on center (not yet sure
how).

3. Make one more cut with the four jaw and tailstock.

Don't involve the tailstock in this test. Regardless of the condition of
the machine, if the tailstock is not dead concentric and in a common plane
with the spindle, it will yield results that are not in keeping with what
you're trying to establish-----if your machine can generate a straight turn.
Do this with no support on the outside of the material-----no support of any
kind.. Not a follow rest, not a steady rest. Use large diameter material
to minimize defection, and insure that the chuck is not allowing the
material to move with tool pressure.

Once you know your machine is cutting straight, you then use the machine to
align the tailstock by either using a test bar, or by machining a long piece
between centers, moving the tailstock such that you eliminate taper. You
must do the free machining first, otherwise you won't know if the machine is
right, or not.

Do not run the center with a part that is chucked. If there is the
slightest misalignment between the spindle and the tailstock, you'll
generate a compromise of not only straightness, but diameter. You may also
generate a three lobed or four lobed cut, depending on the rigidity of the
chuck and tailstock.

Harold

Harold

Ignoramus3975 wrote:
My clausing lathe cuts tapers instead of straight cylinders.

So, Iggy, you made any progress on the lathe?

Jon

On 2008-11-11, Jon Elson wrote:

Ignoramus3975 wrote:
My clausing lathe cuts tapers instead of straight cylinders.

So, Iggy, you made any progress on the lathe?

I spoke to a very nice person who offered to loan me a test bar. I
will hopefully clarify the taper in the headstock tonight and we'll be
able to move on it. It may be easier to do with a test bar that fits
into the Morse taper on the headstock.

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Ignoramus4763 wrote:
On 2008-11-11, Jon Elson wrote:
Ignoramus3975 wrote:
My clausing lathe cuts tapers instead of straight cylinders.

So, Iggy, you made any progress on the lathe?

I spoke to a very nice person who offered to loan me a test bar. I
will hopefully clarify the taper in the headstock tonight and we'll be
able to move on it. It may be easier to do with a test bar that fits
into the Morse taper on the headstock.

Yes, I saw that offer. I usually use 1/2" or 3/4" hardened and ground
shafts, like out of old printers and such. You have to check the bar to
make sure it still is straight, of course. This has worked out quite
well for these sorts of checks. Just mount it in the chuck, turn the
chuck to make sure the bar is straight and not wobbling, and then ride a
dial test indicator up and down it to determine how well the machine is
aligned.

Jon