Well, I think I finally figured it out, although there is still a
mystery.

The problem has been that I could not cut a 1.25" diameter mild steel
bar off in the 3-jaw chuck without house-shaking chatter. This with a
HSS T-blade 1/8" wide in an Aloris BXA-7 holder.

I tried many things, mostly to rule out one possibility or another that
came to mind. The gibs are now all tight, and so on. The Aloris BXA
toolpost replaced the warped Dickson that came with the lathe

On the off chance that loose back hold-down plates on the carriage were
the issue, I used a C-clamp and a piece of aluminum (to protect the bed
way) to clamp carriage firmly to bedway. No effect.

Running fast and slow using the variable speed drive and/or the VFD had
some effect, but gross chatter happened even at very low speeds.

I recently bought a used slotting tool bit, consisting of a 1/16" wide
carbide blade brazed to a 3/8" square shank, the blade protruding about
1/4". Even this chattered.

Huh? How does that work? We are making a tiny groove using this 1000#
machine. This ought to be easy. Time for some reading or re-reading.
Marlow suggested cutting off (parting off) at one third the speed used
for turning, and pressing hard if it chattered. This worked for the
little slotting tool, although I did manage to break it by pressing too
hard. Well, the used bit cost me $0.75, so I happily shed 3/4 of a
tear. Clearly, we have progress here.

So, why then did the tiny slotting tool chatter no matter the speed?
Something must not be stiff enough. But what? I've tightened or
clamped or adjusted just about everything, to no avail.

I woke up the next day with the answer -- torque. I was going slow to
be sure, but was not using the back gear, and so the drive system was
not torsionally rigid enough. When I used the back gear, the chatter
went away, and I was able to part that 1.25" diameter bar off without
danger of shaking the house apart.

What also seemed to help was that I was using a mister to spray lots of
Rustlick WS-5050 emulsion right into the bottom of the deep groove.
Trying to keep the cut lubricated using a hand brush just was not
working, especially when the groove became deeper than it was wide.
However, coolant by itself did not abolish the chatter. The back gear
is essential.

But, I did notice the whole toolpost and holder tilting when I leaned
into the cut, so I'll have to track down if something is still loose and
needs to be adjusted. Or perhaps it's normal, given the forces invloved.

The other thing that happened is that the toolpost and/or compound
rotated perhaps 5 degrees under the stress of parting off, causing the
blade to drift out of perpendicular with the bar being parted. This
caused a lot of trouble until noticed and fixed.

One thing I noticed when I first got the lathe is that one of the two
5/16-18 swivel bolts (055-017) that lock the compound against rotation
had been stretched enough to visibly distort the threads, and I always
wondered why someone would apply that much force. Perhaps this creeping
is the reason. (The stretched bolt was replaced, and the newer bolts
are slightly beefier to the eye and may have been hardened.)

Joe Gwinn

Joseph Gwinn wrote:
Well, I think I finally figured it out, although there is still a
mystery.

The problem has been that I could not cut a 1.25" diameter mild steel
bar off in the 3-jaw chuck without house-shaking chatter. This with a
HSS T-blade 1/8" wide in an Aloris BXA-7 holder.

I tried many things, mostly to rule out one possibility or another that
came to mind. The gibs are now all tight, and so on. The Aloris BXA
toolpost replaced the warped Dickson that came with the lathe

On the off chance that loose back hold-down plates on the carriage were
the issue, I used a C-clamp and a piece of aluminum (to protect the bed
way) to clamp carriage firmly to bedway. No effect.

Running fast and slow using the variable speed drive and/or the VFD had
some effect, but gross chatter happened even at very low speeds.

I recently bought a used slotting tool bit, consisting of a 1/16" wide
carbide blade brazed to a 3/8" square shank, the blade protruding about
1/4". Even this chattered.

Huh? How does that work? We are making a tiny groove using this 1000#
machine. This ought to be easy. Time for some reading or re-reading.
Marlow suggested cutting off (parting off) at one third the speed used
for turning,
I was initially taught in junior high metal class to part at a slow
speed but later in high school machining class where the instructor was
a machinist, he said to run at the recommended speed for the material if
the machine could cope as parting was a cutting operation like any
other. Still works for me. The junior high lathe was a little Southbend
so needed running slow.

and pressing hard if it chattered. This worked for the
little slotting tool, although I did manage to break it by pressing too
hard. Well, the used bit cost me $0.75, so I happily shed 3/4 of a
tear. Clearly, we have progress here.

So, why then did the tiny slotting tool chatter no matter the speed?
Something must not be stiff enough. But what? I've tightened or
clamped or adjusted just about everything, to no avail.

I woke up the next day with the answer -- torque. I was going slow to
be sure, but was not using the back gear, and so the drive system was
not torsionally rigid enough. When I used the back gear, the chatter
went away, and I was able to part that 1.25" diameter bar off without
danger of shaking the house apart.

What also seemed to help was that I was using a mister to spray lots of
Rustlick WS-5050 emulsion right into the bottom of the deep groove.
Trying to keep the cut lubricated using a hand brush just was not
working, especially when the groove became deeper than it was wide.
However, coolant by itself did not abolish the chatter. The back gear
is essential.

But, I did notice the whole toolpost and holder tilting when I leaned
into the cut, so I'll have to track down if something is still loose and
needs to be adjusted. Or perhaps it's normal, given the forces invloved.

You want to find out whats going on there and fix it, not good having it
move and it shouldn't be normal. On my first lathe, a Kerry 1140 (11" x
40"), the first parting tool I used was a 1/4" wide brazed carbide tool,
it was what I could get at the time, and I used that to part 1" free
cutting steel without any problems. The Kerry was fairly worn as well
but the compound and toolpost don't lean under parting loads.
The other thing that happened is that the toolpost and/or compound
rotated perhaps 5 degrees under the stress of parting off, causing the
blade to drift out of perpendicular with the bar being parted. This
caused a lot of trouble until noticed and fixed.

One thing I noticed when I first got the lathe is that one of the two
5/16-18 swivel bolts (055-017) that lock the compound against rotation
had been stretched enough to visibly distort the threads, and I always
wondered why someone would apply that much force. Perhaps this creeping
is the reason. (The stretched bolt was replaced, and the newer bolts
are slightly beefier to the eye and may have been hardened.)

Hopefully the new bolts have sorted the movements problem. I certainly
wouldn't expect parting loads to move the compound unless the bolts were
loose. Both my Kerry and M300 have a similar compound clamping
arrangement to the Clausing and neither needs to be done up particularly
tight to prevent movement. The Kerry uses 5/16" Whitworth IIRC and the
M300 uses M8 so about the same as your 5/16"-18 fasteners.
Joe Gwinn

In article ,
David Billington wrote:

Joseph Gwinn wrote:
Well, I think I finally figured it out, although there is still a
mystery.

The problem has been that I could not cut a 1.25" diameter mild steel
bar off in the 3-jaw chuck without house-shaking chatter. This with a
HSS T-blade 1/8" wide in an Aloris BXA-7 holder.

I tried many things, mostly to rule out one possibility or another that
came to mind. The gibs are now all tight, and so on. The Aloris BXA
toolpost replaced the warped Dickson that came with the lathe

On the off chance that loose back hold-down plates on the carriage were
the issue, I used a C-clamp and a piece of aluminum (to protect the bed
way) to clamp carriage firmly to bedway. No effect.

Running fast and slow using the variable speed drive and/or the VFD had
some effect, but gross chatter happened even at very low speeds.

I recently bought a used slotting tool bit, consisting of a 1/16" wide
carbide blade brazed to a 3/8" square shank, the blade protruding about
1/4". Even this chattered.

Huh? How does that work? We are making a tiny groove using this 1000#
machine. This ought to be easy. Time for some reading or re-reading.
Marlow suggested cutting off (parting off) at one third the speed used
for turning,

I was initially taught in junior high metal class to part at a slow
speed but later in high school machining class where the instructor was
a machinist, he said to run at the recommended speed for the material if
the machine could cope as parting was a cutting operation like any
other. Still works for me. The junior high lathe was a little Southbend
so needed running slow.

It's true that parting off is still a cutting operation, but one
difference is that a parting tool is cutting over a broad area, rather
than close to a point or small radius.

The other issue was that because the toolpost rotated, one whole side
edge of the T-blade was attempting to cut, not just the tip.


and pressing hard if it chattered. This worked for the
little slotting tool, although I did manage to break it by pressing too
hard. Well, the used bit cost me $0.75, so I happily shed 3/4 of a
tear. Clearly, we have progress here.

So, why then did the tiny slotting tool chatter no matter the speed?
Something must not be stiff enough. But what? I've tightened or
clamped or adjusted just about everything, to no avail.

I woke up the next day with the answer -- torque. I was going slow to
be sure, but was not using the back gear, and so the drive system was
not torsionally rigid enough. When I used the back gear, the chatter
went away, and I was able to part that 1.25" diameter bar off without
danger of shaking the house apart.

What also seemed to help was that I was using a mister to spray lots of
Rustlick WS-5050 emulsion right into the bottom of the deep groove.
Trying to keep the cut lubricated using a hand brush just was not
working, especially when the groove became deeper than it was wide.
However, coolant by itself did not abolish the chatter. The back gear
is essential.

But, I did notice the whole toolpost and holder tilting when I leaned
into the cut, so I'll have to track down if something is still loose and
needs to be adjusted. Or perhaps it's normal, given the forces invloved.

You want to find out what's going on there and fix it, not good having it
move and it shouldn't be normal. On my first lathe, a Kerry 1140 (11" x
40"), the first parting tool I used was a 1/4" wide brazed carbide tool,
it was what I could get at the time, and I used that to part 1" free
cutting steel without any problems. The Kerry was fairly worn as well
but the compound and toolpost don't lean under parting loads.

I do want to get to the bottom of this for sure. Maybe the compound is
pulling up and away from the cross-slide, though I don't see how that
could happen without breaking something. Like the central pivot pin,
which shows no signs of distress.


The other thing that happened is that the toolpost and/or compound
rotated perhaps 5 degrees under the stress of parting off, causing the
blade to drift out of perpendicular with the bar being parted. This
caused a lot of trouble until noticed and fixed.

One thing I noticed when I first got the lathe is that one of the two
5/16-18 swivel bolts (055-017) that lock the compound against rotation
had been stretched enough to visibly distort the threads, and I always
wondered why someone would apply that much force. Perhaps this creeping
is the reason. (The stretched bolt was replaced, and the newer bolts
are slightly beefier to the eye and may have been hardened.)

Hopefully the new bolts have sorted the movements problem. I certainly
wouldn't expect parting loads to move the compound unless the bolts were
loose. Both my Kerry and M300 have a similar compound clamping
arrangement to the Clausing and neither needs to be done up particularly
tight to prevent movement. The Kerry uses 5/16" Whitworth IIRC and the
M300 uses M8 so about the same as your 5/16"-18 fasteners.

I replaced only the one stretched bolt. Maybe I should replace both.
It may be that Clausing discovered that the original bolts were not
quite large enough. The difference is in the head. But still I don't
see how cutting off would generate enough force to stretch a 5/16" bolt.
That stretch has to be caused by a human with a wrench, using more
muscle than brain.


Joe Gwinn

Joseph Gwinn wrote:
In article ,
David Billington wrote:


Joseph Gwinn wrote:

Well, I think I finally figured it out, although there is still a
mystery.

The problem has been that I could not cut a 1.25" diameter mild steel
bar off in the 3-jaw chuck without house-shaking chatter. This with a
HSS T-blade 1/8" wide in an Aloris BXA-7 holder.

I tried many things, mostly to rule out one possibility or another that
came to mind. The gibs are now all tight, and so on. The Aloris BXA
toolpost replaced the warped Dickson that came with the lathe

On the off chance that loose back hold-down plates on the carriage were
the issue, I used a C-clamp and a piece of aluminum (to protect the bed
way) to clamp carriage firmly to bedway. No effect.

Running fast and slow using the variable speed drive and/or the VFD had
some effect, but gross chatter happened even at very low speeds.

I recently bought a used slotting tool bit, consisting of a 1/16" wide
carbide blade brazed to a 3/8" square shank, the blade protruding about
1/4". Even this chattered.

Huh? How does that work? We are making a tiny groove using this 1000#
machine. This ought to be easy. Time for some reading or re-reading.
Marlow suggested cutting off (parting off) at one third the speed used
for turning,

I was initially taught in junior high metal class to part at a slow
speed but later in high school machining class where the instructor was
a machinist, he said to run at the recommended speed for the material if
the machine could cope as parting was a cutting operation like any
other. Still works for me. The junior high lathe was a little Southbend
so needed running slow.


It's true that parting off is still a cutting operation, but one
difference is that a parting tool is cutting over a broad area, rather
than close to a point or small radius.

I don't see any difference between parting and a heavy roughing cut. How
well does your Clausing take heavy cuts other than parting. The Clausing
5914 seems to be 2hp like my Kerry, the M300 is 3hp. Both will take 1/8"
depth of cuts in mild steel with the right feed so you don't stall the
machine. The M300 seems a similar build to your Clausing, a bit bigger
throw, the Kerry while smaller seems a bit more heavily built.

Is the 5914 a variant of something else.The excellent site
www.lathes.co.uk doesn't seem to list it that I have seen.
The other issue was that because the toolpost rotated, one whole side
edge of the T-blade was attempting to cut, not just the tip.

I can see that would be a problem and you might have it jam in the cut also.


and pressing hard if it chattered. This worked for the
little slotting tool, although I did manage to break it by pressing too
hard. Well, the used bit cost me $0.75, so I happily shed 3/4 of a
tear. Clearly, we have progress here.

So, why then did the tiny slotting tool chatter no matter the speed?
Something must not be stiff enough. But what? I've tightened or
clamped or adjusted just about everything, to no avail.

I woke up the next day with the answer -- torque. I was going slow to
be sure, but was not using the back gear, and so the drive system was
not torsionally rigid enough. When I used the back gear, the chatter
went away, and I was able to part that 1.25" diameter bar off without
danger of shaking the house apart.

What also seemed to help was that I was using a mister to spray lots of
Rustlick WS-5050 emulsion right into the bottom of the deep groove.
Trying to keep the cut lubricated using a hand brush just was not
working, especially when the groove became deeper than it was wide.
However, coolant by itself did not abolish the chatter. The back gear
is essential.

But, I did notice the whole toolpost and holder tilting when I leaned
into the cut, so I'll have to track down if something is still loose and
needs to be adjusted. Or perhaps it's normal, given the forces invloved.


You want to find out what's going on there and fix it, not good having it
move and it shouldn't be normal. On my first lathe, a Kerry 1140 (11" x
40"), the first parting tool I used was a 1/4" wide brazed carbide tool,
it was what I could get at the time, and I used that to part 1" free
cutting steel without any problems. The Kerry was fairly worn as well
but the compound and toolpost don't lean under parting loads.


I do want to get to the bottom of this for sure. Maybe the compound is
pulling up and away from the cross-slide, though I don't see how that
could happen without breaking something. Like the central pivot pin,
which shows no signs of distress.



The other thing that happened is that the toolpost and/or compound
rotated perhaps 5 degrees under the stress of parting off, causing the
blade to drift out of perpendicular with the bar being parted. This
caused a lot of trouble until noticed and fixed.

One thing I noticed when I first got the lathe is that one of the two
5/16-18 swivel bolts (055-017) that lock the compound against rotation
had been stretched enough to visibly distort the threads, and I always
wondered why someone would apply that much force. Perhaps this creeping
is the reason. (The stretched bolt was replaced, and the newer bolts
are slightly beefier to the eye and may have been hardened.)


Hopefully the new bolts have sorted the movements problem. I certainly
wouldn't expect parting loads to move the compound unless the bolts were
loose. Both my Kerry and M300 have a similar compound clamping
arrangement to the Clausing and neither needs to be done up particularly
tight to prevent movement. The Kerry uses 5/16" Whitworth IIRC and the
M300 uses M8 so about the same as your 5/16"-18 fasteners.


I replaced only the one stretched bolt. Maybe I should replace both.
It may be that Clausing discovered that the original bolts were not
quite large enough. The difference is in the head. But still I don't
see how cutting off would generate enough force to stretch a 5/16" bolt.
That stretch has to be caused by a human with a wrench, using more
muscle than brain.


I agree that someone has done them up far more than is necessary and
stretched them. The ones on my M300 are worn from years of use but are
quite hard and still serviceable. I was wondering if the Clausing bolts
have been stretched to the point they bear on the upper section of the
cut-out in the compound so fight against full tightening. The pics I
have seen of the Clausing seem to show the scallop in the side of the
compound base which the nuts sit in. The Kerry and M300 have nothing
above the fasteners but the roof.
Joe Gwinn

Joseph Gwinn wrote:
Well, I think I finally figured it out, although there is still a
mystery.

{.....]
Joe Gwinn

A quick question how accurate is your chuck and the mild steel material,
are the jaws worn and not gripping the piece fully. I had troubles
holding and turning some 310 stainless which turned out to be the
stainless being slightly triangular and that spiraling down the piece,
the 3 jaw even though quite new would not hold the material well until
a skim cut had been taken to make it round.

On Sat, 05 Apr 2008 13:22:40 -0400, Joseph Gwinn
wrote:
snip
The problem has been that I could not cut a 1.25" diameter mild steel
bar off in the 3-jaw chuck without house-shaking chatter. This with a
HSS T-blade 1/8" wide in an Aloris BXA-7 holder.
snip
=========
As you have discovered "parting off" or cut-off is one of the
more difficult lathe operations.

Many people use a cut-off tool upside down from the back of the
machine with good results. These are generally home made.
http://iwr.ru.ac.za/~iwdf/lathe/reartool.html
http://www.americanmachinist.com/304...se/78007/Issue

kits are available
http://www.hemingwaykits.com/Catalog...%20Version.pdf


for a commercial version see
http://pdf.directindustry.com/pdf/ke...1120-_374.html

also see
http://mcduffee-associates.us/machining/rearcoth.htm
where we machined one as a class project.




Unka' George [George McDuffee]
-------------------------------------------
He that will not apply new remedies,
must expect new evils:
for Time is the greatest innovator: and
if Time, of course, alter things to the worse,
and wisdom and counsel shall not alter them to the better,
what shall be the end?

Francis Bacon (1561-1626), English philosopher, essayist, statesman.
Essays, "Of Innovations" (1597-1625).

"David Billington" wrote in message
...
Joseph Gwinn wrote:
In article ,
David Billington wrote:


Joseph Gwinn wrote:

Well, I think I finally figured it out, although there is still a
mystery.

The problem has been that I could not cut a 1.25" diameter mild steel
bar off in the 3-jaw chuck without house-shaking chatter. This with a
HSS T-blade 1/8" wide in an Aloris BXA-7 holder.

I tried many things, mostly to rule out one possibility or another that
came to mind. The gibs are now all tight, and so on. The Aloris BXA
toolpost replaced the warped Dickson that came with the lathe
On the off chance that loose back hold-down plates on the carriage were
the issue, I used a C-clamp and a piece of aluminum (to protect the bed
way) to clamp carriage firmly to bedway. No effect.

Running fast and slow using the variable speed drive and/or the VFD had
some effect, but gross chatter happened even at very low speeds.

I recently bought a used slotting tool bit, consisting of a 1/16" wide
carbide blade brazed to a 3/8" square shank, the blade protruding about
1/4". Even this chattered.
Huh? How does that work? We are making a tiny groove using this 1000#
machine. This ought to be easy. Time for some reading or re-reading.
Marlow suggested cutting off (parting off) at one third the speed used
for turning,
I was initially taught in junior high metal class to part at a slow
speed but later in high school machining class where the instructor was
a machinist, he said to run at the recommended speed for the material if
the machine could cope as parting was a cutting operation like any
other. Still works for me. The junior high lathe was a little Southbend
so needed running slow.


It's true that parting off is still a cutting operation, but one
difference is that a parting tool is cutting over a broad area, rather
than close to a point or small radius.

I don't see any difference between parting and a heavy roughing cut. How
well does your Clausing take heavy cuts other than parting. The Clausing
5914 seems to be 2hp like my Kerry, the M300 is 3hp. Both will take 1/8"
depth of cuts in mild steel with the right feed so you don't stall the
machine. The M300 seems a similar build to your Clausing, a bit bigger
throw, the Kerry while smaller seems a bit more heavily built.

One difference is that on a heavy standard cut, there is sonewhere for the
chips to go. On a deep parting cut, the lack of chip evacuation will cause
trouble by itself. An air hose can be used to remove chips during the cut.
Air blown down the length of the top of the parting tool will lift the chips
up out of the way. Pressurized air can be an effective machining tool. At
work, we have used vortex air tubes to blow chilled air onto specialty
materials cut in the screw machines. This is the same basic thing as a
personal backpack air conditioner for use in media blasting suits and such.
See

http://en.wikipedia.org/wiki/Vortex_tube

RJ

Is the 5914 a variant of something else.The excellent site
www.lathes.co.uk doesn't seem to list it that I have seen.
The other issue was that because the toolpost rotated, one whole side
edge of the T-blade was attempting to cut, not just the tip.

I can see that would be a problem and you might have it jam in the cut
also.


and pressing hard if it chattered. This worked for the little slotting
tool, although I did manage to break it by pressing too hard. Well,
the used bit cost me $0.75, so I happily shed 3/4 of a tear. Clearly,
we have progress here.

So, why then did the tiny slotting tool chatter no matter the speed?
Something must not be stiff enough. But what? I've tightened or
clamped or adjusted just about everything, to no avail.

I woke up the next day with the answer -- torque. I was going slow to
be sure, but was not using the back gear, and so the drive system was
not torsionally rigid enough. When I used the back gear, the chatter
went away, and I was able to part that 1.25" diameter bar off without
danger of shaking the house apart.

What also seemed to help was that I was using a mister to spray lots of
Rustlick WS-5050 emulsion right into the bottom of the deep groove.
Trying to keep the cut lubricated using a hand brush just was not
working, especially when the groove became deeper than it was wide.
However, coolant by itself did not abolish the chatter. The back gear
is essential.

But, I did notice the whole toolpost and holder tilting when I leaned
into the cut, so I'll have to track down if something is still loose
and needs to be adjusted. Or perhaps it's normal, given the forces
invloved.

You want to find out what's going on there and fix it, not good having
it move and it shouldn't be normal. On my first lathe, a Kerry 1140 (11"
x 40"), the first parting tool I used was a 1/4" wide brazed carbide
tool, it was what I could get at the time, and I used that to part 1"
free cutting steel without any problems. The Kerry was fairly worn as
well but the compound and toolpost don't lean under parting loads.


I do want to get to the bottom of this for sure. Maybe the compound is
pulling up and away from the cross-slide, though I don't see how that
could happen without breaking something. Like the central pivot pin,
which shows no signs of distress.



The other thing that happened is that the toolpost and/or compound
rotated perhaps 5 degrees under the stress of parting off, causing the
blade to drift out of perpendicular with the bar being parted. This
caused a lot of trouble until noticed and fixed.

One thing I noticed when I first got the lathe is that one of the two
5/16-18 swivel bolts (055-017) that lock the compound against rotation
had been stretched enough to visibly distort the threads, and I always
wondered why someone would apply that much force. Perhaps this
creeping is the reason. (The stretched bolt was replaced, and the
newer bolts are slightly beefier to the eye and may have been
hardened.)

Hopefully the new bolts have sorted the movements problem. I certainly
wouldn't expect parting loads to move the compound unless the bolts were
loose. Both my Kerry and M300 have a similar compound clamping
arrangement to the Clausing and neither needs to be done up particularly
tight to prevent movement. The Kerry uses 5/16" Whitworth IIRC and the
M300 uses M8 so about the same as your 5/16"-18 fasteners.


I replaced only the one stretched bolt. Maybe I should replace both. It
may be that Clausing discovered that the original bolts were not quite
large enough. The difference is in the head. But still I don't see how
cutting off would generate enough force to stretch a 5/16" bolt. That
stretch has to be caused by a human with a wrench, using more muscle than
brain.


I agree that someone has done them up far more than is necessary and
stretched them. The ones on my M300 are worn from years of use but are
quite hard and still serviceable. I was wondering if the Clausing bolts
have been stretched to the point they bear on the upper section of the
cut-out in the compound so fight against full tightening. The pics I have
seen of the Clausing seem to show the scallop in the side of the compound
base which the nuts sit in. The Kerry and M300 have nothing above the
fasteners but the roof.
Joe Gwinn

I found loose spinde bearings caused my lathe to chatter real bad
while parting. I tightened up the bearings and the chatter went away.
Something to look at.

On Sat, 05 Apr 2008 20:03:09 +0100, David Billington
wrote:


But, I did notice the whole toolpost and holder tilting when I leaned
into the cut, so I'll have to track down if something is still loose and
needs to be adjusted. Or perhaps it's normal, given the forces invloved.

You want to find out whats going on there and fix it, not good having it
move and it shouldn't be normal.


I agree. Something is seriously worn, not making countact with the
bedways, or there is not cutting edge on the tool....

What exactly does "lean on it" mean?

Everything bends if you "lean on it" enough.

With cutting tools with the mechanical advantage of a crossslide..you
shouldnt have to "lean on it"

If you do..your tools are ****ed up.

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

On Sat, 05 Apr 2008 16:39:16 -0400, Joseph Gwinn
wrote:


I was initially taught in junior high metal class to part at a slow
speed but later in high school machining class where the instructor was
a machinist, he said to run at the recommended speed for the material if
the machine could cope as parting was a cutting operation like any
other. Still works for me. The junior high lathe was a little Southbend
so needed running slow.

It's true that parting off is still a cutting operation, but one
difference is that a parting tool is cutting over a broad area, rather
than close to a point or small radius.

The other issue was that because the toolpost rotated, one whole side
edge of the T-blade was attempting to cut, not just the tip.


Thats very common with quick change tool holders. leverage with the
tool hanging out to the left/right of cross slide centerling.

Tighten up the tool post, or put a bit of yellow legal pad paper
under it.

And learn to sharpen/setup/line up your cutting tools better. A cut
shouldnt take all that much pressure to accomplish unless they are
dull, or you are feeding way too fast

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

Dan wrote:
I found loose spinde bearings caused my lathe to chatter real bad
while parting. I tightened up the bearings and the chatter went away.
Something to look at.

I have to agree, I have had the same experience.

cheers
T.Alan

In article ,
Gunner Asch wrote:

On Sat, 05 Apr 2008 16:39:16 -0400, Joseph Gwinn
wrote:


I was initially taught in junior high metal class to part at a slow
speed but later in high school machining class where the instructor was
a machinist, he said to run at the recommended speed for the material if
the machine could cope as parting was a cutting operation like any
other. Still works for me. The junior high lathe was a little Southbend
so needed running slow.

It's true that parting off is still a cutting operation, but one
difference is that a parting tool is cutting over a broad area, rather
than close to a point or small radius.

The other issue was that because the toolpost rotated, one whole side
edge of the T-blade was attempting to cut, not just the tip.


Thats very common with quick change tool holders. leverage with the
tool hanging out to the left/right of cross slide centerline.

Aloris claimed it was not a problem, but I certainly had the problem
with the Dickson toolpost. The Aloris does have a blind ~3/8" diameter
hole in the bottom that appears to be intended to accept an
anti-rotation pin.


Tighten up the tool post, or put a bit of yellow legal-pad paper
under it.

OK. It was pretty tight. Is yellow legal paper special?


And learn to sharpen/setup/line up your cutting tools better. A cut
shouldn't take all that much pressure to accomplish unless they are
dull, or you are feeding way too fast

It was not quite razor sharp, but it wasn't dull either. But it won't
hurt to sharpen it.

I suspect the real problem (aside from the toolpost rotating) was that I
was simply pushing too hard, as I learn the feel of cutting off. This
is the part that must be learned by using the lathe, that cannot be
learned by reading books.

Joe Gwinn

In article , Dan@ (Dan ) wrote:

I found loose spinde bearings caused my lathe to chatter real bad
while parting. I tightened up the bearings and the chatter went away.
Something to look at.

I did think of this possibility, based on other postings, so I went
through the checkout procedure in the Clausing manual.

Basically, with a 9" drive plate (well, mine is 6") in place and the
leadscrew not connected, let the lathe run for an hour to warm up, then
stop the lathe, pull the pin so the spindle is disconnected from the
drive, and give the spindle a spin by hand. It should spin to a stop in
about one turn.

It spun down in about one turn when I followed the procedure, and made
no odd noises, so loose spindle bearings do not appear to be a problem.

Joe Gwinn

In article ,
David Billington wrote:

Joseph Gwinn wrote:
Well, I think I finally figured it out, although there is still a
mystery.

{.....]
Joe Gwinn

A quick question how accurate is your chuck and the mild steel material,
are the jaws worn and not gripping the piece fully. I had troubles
holding and turning some 310 stainless which turned out to be the
stainless being slightly triangular and that spiraling down the piece,
the 3 jaw even though quite new would not hold the material well until
a skim cut had been taken to make it round.

The chuck, while old and with cosmetic rust, appears to have had little
use. I took it apart and gave it a cleaning and greasing, but the
innards were pristine. It appears to be made by Pratt Burnerd, and
appears to be original equipment supplied with the 5914.

The steel bar was rusty and irregular and was in fact loose in the
chuck, so I did give the bar a skim cut. This allowed the bar to be
held securely, but it still chattered badly until I used the backgear.

Joe Gwinn

In article ,
F. George McDuffee wrote:

On Sat, 05 Apr 2008 13:22:40 -0400, Joseph Gwinn
wrote:
snip
The problem has been that I could not cut a 1.25" diameter mild steel
bar off in the 3-jaw chuck without house-shaking chatter. This with a
HSS T-blade 1/8" wide in an Aloris BXA-7 holder.
snip
=========
As you have discovered "parting off" or cut-off is one of the
more difficult lathe operations.

Many people use a cut-off tool upside down from the back of the
machine with good results. These are generally home made.
http://iwr.ru.ac.za/~iwdf/lathe/reartool.html
http://www.americanmachinist.com/304...se/78007/Issue

kits are available
http://www.hemingwaykits.com/Catalog...%20Version.pdf

The problem with the 5914 is that the cross-slide won't go far enough
back to allow for two toolposts, and has just one T-slot. Apparently,
there is a two-slot cross-slide available for the Clausing 5900-series
lathes, but I have not seen one. DoN may have one.


for a commercial version see
http://pdf.directindustry.com/pdf/kennametal/lathe-tooling-catalog-4010/7354-1120-_374.html

Man does Kennametal have a big catalog. What I didn't see was a
comparison of the advantages and disadvantages of the various methods of
holding inserts.


Joe Gwinn


also see
http://mcduffee-associates.us/machining/rearcoth.htm
where we machined one as a class project.




Unka' George [George McDuffee]
-------------------------------------------
He that will not apply new remedies,
must expect new evils:
for Time is the greatest innovator: and
if Time, of course, alter things to the worse,
and wisdom and counsel shall not alter them to the better,
what shall be the end?

Francis Bacon (1561-1626), English philosopher, essayist, statesman.
Essays, "Of Innovations" (1597-1625).

In article ,
David Billington wrote:

Joseph Gwinn wrote:
In article ,
David Billington wrote:


Joseph Gwinn wrote:

Well, I think I finally figured it out, although there is still a
mystery.

The problem has been that I could not cut a 1.25" diameter mild steel
bar off in the 3-jaw chuck without house-shaking chatter. This with a
HSS T-blade 1/8" wide in an Aloris BXA-7 holder.

I tried many things, mostly to rule out one possibility or another that
came to mind. The gibs are now all tight, and so on. The Aloris BXA
toolpost replaced the warped Dickson that came with the lathe

On the off chance that loose back hold-down plates on the carriage were
the issue, I used a C-clamp and a piece of aluminum (to protect the bed
way) to clamp carriage firmly to bedway. No effect.

Running fast and slow using the variable speed drive and/or the VFD had
some effect, but gross chatter happened even at very low speeds.

I recently bought a used slotting tool bit, consisting of a 1/16" wide
carbide blade brazed to a 3/8" square shank, the blade protruding about
1/4". Even this chattered.

Huh? How does that work? We are making a tiny groove using this 1000#
machine. This ought to be easy. Time for some reading or re-reading.
Marlow suggested cutting off (parting off) at one third the speed used
for turning,

I was initially taught in junior high metal class to part at a slow
speed but later in high school machining class where the instructor was
a machinist, he said to run at the recommended speed for the material if
the machine could cope as parting was a cutting operation like any
other. Still works for me. The junior high lathe was a little Southbend
so needed running slow.

It's true that parting off is still a cutting operation, but one
difference is that a parting tool is cutting over a broad area, rather
than close to a point or small radius.

I don't see any difference between parting and a heavy roughing cut. How
well does your Clausing take heavy cuts other than parting? The Clausing
5914 seems to be 2hp like my Kerry, the M300 is 3hp. Both will take 1/8"
depth of cuts in mild steel with the right feed so you don't stall the
machine. The M300 seems a similar build to your Clausing, a bit bigger
throw, the Kerry while smaller seems a bit more heavily built.

I have taken 0.100" deep cuts (0.200" diameter reduction) without
difficulty, cutting with the carriage moving under power to the left.

Have not yet tried to cut 0.125" deep.

Hitting a shoulder 0.250" deep while moving to the left causes chatter.

The motor in the 5914 is 2 HP.


Is the 5914 a variant of something else? The excellent site
www.lathes.co.uk doesn't seem to list it that I have seen.

I don't know that the 5914 is anything other than Clausing. Someone
else may know the history.

I've read that the asian lathes of that size were based on Clausing, but
I assume that the real story is a bit more complicated than that.


While googling on "Clausing 5914", I did find a nice picture that showed
the lantern toolpost with slotted ring discussed in another thread:
http://www.pbase.com/clausenm/image/26339314. So, I bet that the
slotted ring is original Clausing.


The other issue was that because the toolpost rotated, one whole side
edge of the T-blade was attempting to cut, not just the tip.

I can see that would be a problem and you might have it jam in the cut also.

One of the groove faces was a section of a sphere, but badly galled.

And things went far better when I straightened the blade out.


and pressing hard if it chattered. This worked for the
little slotting tool, although I did manage to break it by pressing too
hard. Well, the used bit cost me $0.75, so I happily shed 3/4 of a
tear. Clearly, we have progress here.

So, why then did the tiny slotting tool chatter no matter the speed?
Something must not be stiff enough. But what? I've tightened or
clamped or adjusted just about everything, to no avail.

I woke up the next day with the answer -- torque. I was going slow to
be sure, but was not using the back gear, and so the drive system was
not torsionally rigid enough. When I used the back gear, the chatter
went away, and I was able to part that 1.25" diameter bar off without
danger of shaking the house apart.

What also seemed to help was that I was using a mister to spray lots of
Rustlick WS-5050 emulsion right into the bottom of the deep groove.
Trying to keep the cut lubricated using a hand brush just was not
working, especially when the groove became deeper than it was wide.
However, coolant by itself did not abolish the chatter. The back gear
is essential.

But, I did notice the whole toolpost and holder tilting when I leaned
into the cut, so I'll have to track down if something is still loose and
needs to be adjusted. Or perhaps it's normal, given the forces invloved.


You want to find out what's going on there and fix it, not good having it
move and it shouldn't be normal. On my first lathe, a Kerry 1140 (11" x
40"), the first parting tool I used was a 1/4" wide brazed carbide tool,
it was what I could get at the time, and I used that to part 1" free
cutting steel without any problems. The Kerry was fairly worn as well
but the compound and toolpost don't lean under parting loads.


I do want to get to the bottom of this for sure. Maybe the compound is
pulling up and away from the cross-slide, though I don't see how that
could happen without breaking something. Like the central pivot pin,
which shows no signs of distress.



The other thing that happened is that the toolpost and/or compound
rotated perhaps 5 degrees under the stress of parting off, causing the
blade to drift out of perpendicular with the bar being parted. This
caused a lot of trouble until noticed and fixed.

One thing I noticed when I first got the lathe is that one of the two
5/16-18 swivel bolts (055-017) that lock the compound against rotation
had been stretched enough to visibly distort the threads, and I always
wondered why someone would apply that much force. Perhaps this creeping
is the reason. (The stretched bolt was replaced, and the newer bolts
are slightly beefier to the eye and may have been hardened.)


Hopefully the new bolts have sorted the movements problem. I certainly
wouldn't expect parting loads to move the compound unless the bolts were
loose. Both my Kerry and M300 have a similar compound clamping
arrangement to the Clausing and neither needs to be done up particularly
tight to prevent movement. The Kerry uses 5/16" Whitworth IIRC and the
M300 uses M8 so about the same as your 5/16"-18 fasteners.


I replaced only the one stretched bolt. Maybe I should replace both.
It may be that Clausing discovered that the original bolts were not
quite large enough. The difference is in the head. But still I don't
see how cutting off would generate enough force to stretch a 5/16" bolt.
That stretch has to be caused by a human with a wrench, using more
muscle than brain.


I agree that someone has done them up far more than is necessary and
stretched them. The ones on my M300 are worn from years of use but are
quite hard and still serviceable. I was wondering if the Clausing bolts
have been stretched to the point they bear on the upper section of the
cut-out in the compound so fight against full tightening. The pics I
have seen of the Clausing seem to show the scallop in the side of the
compound base which the nuts sit in. The Kerry and M300 have nothing
above the fasteners but the roof.

The end of the stretched bolt was riding on the top side of the slot, as
you suspected. I filed off enough of the bolt to prevent pressure on
the upper side of the slot until the replacement bolt arrived. The
metal (cast iron) above the upper side of the slot is rather thin, and
I'm surprised it wasn't broken off, but there was no visible damage.

Joe Gwinn

In article ,
"Backlash" wrote:

"David Billington" wrote in message
...
Joseph Gwinn wrote:
In article ,
David Billington wrote:


Joseph Gwinn wrote:

Well, I think I finally figured it out, although there is still a
mystery.

The problem has been that I could not cut a 1.25" diameter mild steel
bar off in the 3-jaw chuck without house-shaking chatter. This with a
HSS T-blade 1/8" wide in an Aloris BXA-7 holder.

I tried many things, mostly to rule out one possibility or another that
came to mind. The gibs are now all tight, and so on. The Aloris BXA
toolpost replaced the warped Dickson that came with the lathe
On the off chance that loose back hold-down plates on the carriage were
the issue, I used a C-clamp and a piece of aluminum (to protect the bed
way) to clamp carriage firmly to bedway. No effect.

Running fast and slow using the variable speed drive and/or the VFD had
some effect, but gross chatter happened even at very low speeds.

I recently bought a used slotting tool bit, consisting of a 1/16" wide
carbide blade brazed to a 3/8" square shank, the blade protruding about
1/4". Even this chattered.
Huh? How does that work? We are making a tiny groove using this 1000#
machine. This ought to be easy. Time for some reading or re-reading.
Marlow suggested cutting off (parting off) at one third the speed used
for turning,
I was initially taught in junior high metal class to part at a slow
speed but later in high school machining class where the instructor was
a machinist, he said to run at the recommended speed for the material if
the machine could cope as parting was a cutting operation like any
other. Still works for me. The junior high lathe was a little Southbend
so needed running slow.


It's true that parting off is still a cutting operation, but one
difference is that a parting tool is cutting over a broad area, rather
than close to a point or small radius.

I don't see any difference between parting and a heavy roughing cut. How
well does your Clausing take heavy cuts other than parting. The Clausing
5914 seems to be 2hp like my Kerry, the M300 is 3hp. Both will take 1/8"
depth of cuts in mild steel with the right feed so you don't stall the
machine. The M300 seems a similar build to your Clausing, a bit bigger
throw, the Kerry while smaller seems a bit more heavily built.

One difference is that on a heavy standard cut, there is sonewhere for the
chips to go. On a deep parting cut, the lack of chip evacuation will cause
trouble by itself. An air hose can be used to remove chips during the cut.
Air blown down the length of the top of the parting tool will lift the chips
up out of the way. Pressurized air can be an effective machining tool.

I would be afraid that the chips would go everywhere, including into
people's eyes.

I did use a Noga mister spraying downward from close range, straight
into the groove, so the cutting point would be flooded with emulsion.
There were no flying chips. There were flying drops of blue emulsion.

I could try sending the mist into the groove parallel to the blade.


At work, we have used vortex air tubes to blow chilled air onto specialty
materials cut in the screw machines. This is the same basic thing as a
personal backpack air conditioner for use in media blasting suits and such.
See

http://en.wikipedia.org/wiki/Vortex_tube

I bet it takes a LARGE compressor to stay ahead of a vortex tube.


Joe Gwinn

"Joseph Gwinn" wrote in message
...
In article ,
F. George McDuffee wrote:

On Sat, 05 Apr 2008 13:22:40 -0400, Joseph Gwinn
wrote:
snip
The problem has been that I could not cut a 1.25" diameter mild steel
bar off in the 3-jaw chuck without house-shaking chatter. This with a
HSS T-blade 1/8" wide in an Aloris BXA-7 holder.
snip
=========
As you have discovered "parting off" or cut-off is one of the
more difficult lathe operations.

Many people use a cut-off tool upside down from the back of the
machine with good results. These are generally home made.
http://iwr.ru.ac.za/~iwdf/lathe/reartool.html
http://www.americanmachinist.com/304...se/78007/Issue

kits are available
http://www.hemingwaykits.com/Catalog...%20Version.pdf

The problem with the 5914 is that the cross-slide won't go far enough
back to allow for two toolposts, and has just one T-slot. Apparently,
there is a two-slot cross-slide available for the Clausing 5900-series
lathes, but I have not seen one. DoN may have one.


snip

That sounds like the production cross slide, which was probably intended for
use with a bed turret. They came in two versions I think, those being
leadscrew and lever types. I've got the leadscrew type and never found the
need to try it, mostly as it seems best suited to production work and I'm
more into one-offs or very short runs.

On Sun, 06 Apr 2008 16:40:47 -0400, Joseph Gwinn
wrote:

In article ,
"Backlash" wrote:

At work, we have used vortex air tubes to blow chilled air onto specialty
materials cut in the screw machines. This is the same basic thing as a
personal backpack air conditioner for use in media blasting suits and such.
See

http://en.wikipedia.org/wiki/Vortex_tube

I bet it takes a LARGE compressor to stay ahead of a vortex tube.


They have them - Most big production shops use lots of air and have
multiple 25-HP or larger screw type compressors to supply it. And
they run the primary in continuous unloader mode and cut in the
secondaries as needed, and they are usually on a sequencer to spread
the run-time and wear around.

Or there's a manual switch so the plant maintenance person can swap
the starting order weekly.

They might have a small 10-HP piston unit as the "Oh ****" backup,
and to supply any needed nights and weekends air use loads.

There are "Small" vortex tubes that only take 2 CFM to 8 CFM @100
PSI, and that's well within the range of a 5 'real' HP (Not "5 Sears
HP") 2-stage compressor. One at a time of course, and realize that
you are wasting a lot of energy compressing shop air just to get that
little bit of cold air out the end.

-- Bruce --

On Sun, 06 Apr 2008 14:42:55 -0400, Joseph Gwinn
wrote:

In article ,
Gunner Asch wrote:

On Sat, 05 Apr 2008 16:39:16 -0400, Joseph Gwinn
wrote:


I was initially taught in junior high metal class to part at a slow
speed but later in high school machining class where the instructor was
a machinist, he said to run at the recommended speed for the material if
the machine could cope as parting was a cutting operation like any
other. Still works for me. The junior high lathe was a little Southbend
so needed running slow.

It's true that parting off is still a cutting operation, but one
difference is that a parting tool is cutting over a broad area, rather
than close to a point or small radius.

The other issue was that because the toolpost rotated, one whole side
edge of the T-blade was attempting to cut, not just the tip.


Thats very common with quick change tool holders. leverage with the
tool hanging out to the left/right of cross slide centerline.

Aloris claimed it was not a problem, but I certainly had the problem
with the Dickson toolpost. The Aloris does have a blind ~3/8" diameter
hole in the bottom that appears to be intended to accept an
anti-rotation pin.

I have KDK on all my machines, including the Hardinge HLV-H..and it
will twist if I screw up.


Tighten up the tool post, or put a bit of yellow legal-pad paper
under it.

OK. It was pretty tight. Is yellow legal paper special?

It provides a nice friction surface between the block and the
compound. Even when oily.


And learn to sharpen/setup/line up your cutting tools better. A cut
shouldn't take all that much pressure to accomplish unless they are
dull, or you are feeding way too fast

It was not quite razor sharp, but it wasn't dull either. But it won't
hurt to sharpen it.

I suspect the real problem (aside from the toolpost rotating) was that I
was simply pushing too hard, as I learn the feel of cutting off. This
is the part that must be learned by using the lathe, that cannot be
learned by reading books.

Joe Gwinn

Good thinking and sorta echoed my own thoughts. It takes time to get
a feel, or read the recommended speeds and feeds and set your travel
accordingly.

I tend to make blue chips..push harder than most might, but I know my
machines, my tooling.

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

In article ,
Gunner Asch wrote:

On Sun, 06 Apr 2008 14:42:55 -0400, Joseph Gwinn
wrote:

In article ,
Gunner Asch wrote:

On Sat, 05 Apr 2008 16:39:16 -0400, Joseph Gwinn
wrote:


I was initially taught in junior high metal class to part at a slow
speed but later in high school machining class where the instructor was
a machinist, he said to run at the recommended speed for the material
if
the machine could cope as parting was a cutting operation like any
other. Still works for me. The junior high lathe was a little
Southbend
so needed running slow.

It's true that parting off is still a cutting operation, but one
difference is that a parting tool is cutting over a broad area, rather
than close to a point or small radius.

The other issue was that because the toolpost rotated, one whole side
edge of the T-blade was attempting to cut, not just the tip.


Thats very common with quick change tool holders. leverage with the
tool hanging out to the left/right of cross slide centerline.

Aloris claimed it was not a problem, but I certainly had the problem
with the Dickson toolpost. The Aloris does have a blind ~3/8" diameter
hole in the bottom that appears to be intended to accept an
anti-rotation pin.

I have KDK on all my machines, including the Hardinge HLV-H..and it
will twist if I screw up.

KDK toolposts also have polished bottoms, I assume.

How does KDK compare to Aloris?


Tighten up the tool post, or put a bit of yellow legal-pad paper
under it.

OK. It was pretty tight. Is yellow legal paper special?

It provides a nice friction surface between the block and the
compound. Even when oily.

Ahh. That was my question.

I use a water-oil emulsion for cutting, and I worried that the water
would turn the paper into mush. Maybe the paper needs to be soaked in
way oil first.

I was also thinking of using electrical "fishpaper" (vulcanized fiber)
in place of the legal paper. Fishpaper is *very* strong. Fish are not
involved; I have no idea where the name came from.

I've also been thinking that the paper might benefit from being sealed
with shellac. Application would be by dipping in shellac diluted with
alcohol.


And learn to sharpen/setup/line up your cutting tools better. A cut
shouldn't take all that much pressure to accomplish unless they are
dull, or you are feeding way too fast

It was not quite razor sharp, but it wasn't dull either. But it won't
hurt to sharpen it.

I suspect the real problem (aside from the toolpost rotating) was that I
was simply pushing too hard, as I learn the feel of cutting off. This
is the part that must be learned by using the lathe, that cannot be
learned by reading books.

Joe Gwinn

Good thinking and sorta echoed my own thoughts. It takes time to get
a feel, or read the recommended speeds and feeds and set your travel
accordingly.

I tend to make blue chips..push harder than most might, but I know my
machines, my tooling.

Well, I've been managing pale yellow to brown chips mostly, and did
manage blue while doing roughing-cut experiments. This while using
brushed-on black sulfur oil. But since I started using the sprayed
water-oil emulsion, things have been boringly cool, and all chips are
shiney. But the emulsion is baby blue.

Joe Gwinn

I have a 5914 that shakes hard with a cut off blade.
I am tense, and when the shaking causes something to fall over in the
pan of the lathe, I just about jump out of my skin.

I now hack saw off pieces and then face it with the lathe.

On Sun, 06 Apr 2008 21:43:27 -0400, Joseph Gwinn
wrote:


Aloris claimed it was not a problem, but I certainly had the problem
with the Dickson toolpost. The Aloris does have a blind ~3/8" diameter
hole in the bottom that appears to be intended to accept an
anti-rotation pin.

I have KDK on all my machines, including the Hardinge HLV-H..and it
will twist if I screw up.

KDK toolposts also have polished bottoms, I assume.

How does KDK compare to Aloris?

Equally good. You will find far far more KDK in commercial shops than
Aloris though, for some reason.


Tighten up the tool post, or put a bit of yellow legal-pad paper
under it.

OK. It was pretty tight. Is yellow legal paper special?

It provides a nice friction surface between the block and the
compound. Even when oily.

Ahh. That was my question.

I use a water-oil emulsion for cutting, and I worried that the water
would turn the paper into mush. Maybe the paper needs to be soaked in
way oil first.

It wont turn into mush when its clamped under the tool holder.

I was also thinking of using electrical "fishpaper" (vulcanized fiber)
in place of the legal paper. Fishpaper is *very* strong. Fish are not
involved; I have no idea where the name came from.

I've also been thinking that the paper might benefit from being sealed
with shellac. Application would be by dipping in shellac diluted with
alcohol.

Try the yellow paper. Ill send you a dollar to buy a pad at the 99c
store. G

And learn to sharpen/setup/line up your cutting tools better. A cut
shouldn't take all that much pressure to accomplish unless they are
dull, or you are feeding way too fast

It was not quite razor sharp, but it wasn't dull either. But it won't
hurt to sharpen it.

I suspect the real problem (aside from the toolpost rotating) was that I
was simply pushing too hard, as I learn the feel of cutting off. This
is the part that must be learned by using the lathe, that cannot be
learned by reading books.

Joe Gwinn

Good thinking and sorta echoed my own thoughts. It takes time to get
a feel, or read the recommended speeds and feeds and set your travel
accordingly.

I tend to make blue chips..push harder than most might, but I know my
machines, my tooling.

Well, I've been managing pale yellow to brown chips mostly, and did
manage blue while doing roughing-cut experiments. This while using
brushed-on black sulfur oil. But since I started using the sprayed
water-oil emulsion, things have been boringly cool, and all chips are
shiney. But the emulsion is baby blue.

Joe Gwinn


Black sulpher oil works good for pipe threading using dies, but not so
great for lathe work. You have to thin it out a bit.

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

On 2008-04-06, Joseph Gwinn wrote:
In article , Dan@ (Dan ) wrote:

I found loose spinde bearings caused my lathe to chatter real bad
while parting. I tightened up the bearings and the chatter went away.
Something to look at.

I did think of this possibility, based on other postings, so I went
through the checkout procedure in the Clausing manual.

Basically, with a 9" drive plate (well, mine is 6") in place and the
leadscrew not connected, let the lathe run for an hour to warm up, then
stop the lathe, pull the pin so the spindle is disconnected from the
drive, and give the spindle a spin by hand. It should spin to a stop in
about one turn.

It spun down in about one turn when I followed the procedure, and made
no odd noises, so loose spindle bearings do not appear to be a problem.

Hmm ... with a 6" plate instead of 9" you have less flywheel
effect, so I would make the test time about 1/2 turn.

Enjoy,
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 ---

On 2008-04-06, Joseph Gwinn wrote:
In article ,
F. George McDuffee wrote:


[ ... ]

Many people use a cut-off tool upside down from the back of the
machine with good results. These are generally home made.
http://iwr.ru.ac.za/~iwdf/lathe/reartool.html
http://www.americanmachinist.com/304...se/78007/Issue

kits are available
http://www.hemingwaykits.com/Catalog...%20Version.pdf

The problem with the 5914 is that the cross-slide won't go far enough
back to allow for two toolposts, and has just one T-slot. Apparently,
there is a two-slot cross-slide available for the Clausing 5900-series
lathes, but I have not seen one. DoN may have one.

Don't I wish! I've only seen them in an old catalog which was
scanned for me.

for a commercial version see
http://pdf.directindustry.com/pdf/kennametal/lathe-tooling-catalog-4010/7354-1120-_374.html

Man does Kennametal have a big catalog. What I didn't see was a
comparison of the advantages and disadvantages of the various methods of
holding inserts.


Typically, I think that you pick a system which matches what you
already have. At least that is what I did -- starting with a couple of
good holder from eBay auctions along with 100 matching inserts for each. :-)

Enjoy,
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 ---

On 2008-04-07, Clark Magnuson wrote:
I have a 5914 that shakes hard with a cut off blade.
I am tense, and when the shaking causes something to fall over in the
pan of the lathe, I just about jump out of my skin.

I have no problems with my Clausing 5418 -- pretty much the same
except step pulley and manual belt changes. I always part of with the
backgear.

I now hack saw off pieces and then face it with the lathe.

Well ... for larger workpieces, I use the 4x6"
horizontal/vertical cheap bandsaw. But I will certainly part off
workpieces which I feed through the spindle -- both up to 1" in the 5C
collets, and the hex 12L14 stock which is the maximum which will fit
through the 1-3/8" ID spindle with the drawtube removed. (I think that
is 1-1/8" hex, but until I have to buy more, it won't matter much.) The
hex stock is held in the 3-jaw chuck.

If I ever do see chatter when parting off, I know that it is
time to tighten the spindle draw-up ring again. (I swapped spindles to
get an L-00 spindle nose in place of the 2-1/4x8 which came with the
lathe.

Enjoy,
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 ---

In article ,
"DoN. Nichols" wrote:

On 2008-04-06, Joseph Gwinn wrote:
In article ,
F. George McDuffee wrote:


[ ... ]

Many people use a cut-off tool upside down from the back of the
machine with good results. These are generally home made.
http://iwr.ru.ac.za/~iwdf/lathe/reartool.html
http://www.americanmachinist.com/304...se/78007/Issue

kits are available
http://www.hemingwaykits.com/Catalog...%20Version.pdf

The problem with the 5914 is that the cross-slide won't go far enough
back to allow for two toolposts, and has just one T-slot. Apparently,
there is a two-slot cross-slide available for the Clausing 5900-series
lathes, but I have not seen one. DoN may have one.

Don't I wish! I've only seen them in an old catalog which was
scanned for me.

Hmm. Maybe someday.


for a commercial version see
http://pdf.directindustry.com/pdf/ke...atalog-4010/73
54-1120-_374.html

Man does Kennametal have a big catalog. What I didn't see was a
comparison of the advantages and disadvantages of the various methods of
holding inserts.

Typically, I think that you pick a system which matches what you
already have. At least that is what I did -- starting with a couple of
good holder from eBay auctions along with 100 matching inserts for each. :-)

I'm leaning towards buying new, not wanting to wait a year to get lucky.
Now you know that the day after I order the new item, three fine used
items will turn up on eBay, for a third the price.

Joe Gwinn

In article ,
"DoN. Nichols" wrote:

On 2008-04-06, Joseph Gwinn wrote:
In article , Dan@ (Dan ) wrote:

I found loose spinde bearings caused my lathe to chatter real bad
while parting. I tightened up the bearings and the chatter went away.
Something to look at.

I did think of this possibility, based on other postings, so I went
through the checkout procedure in the Clausing manual.

Basically, with a 9" drive plate (well, mine is 6") in place and the
leadscrew not connected, let the lathe run for an hour to warm up, then
stop the lathe, pull the pin so the spindle is disconnected from the
drive, and give the spindle a spin by hand. It should spin to a stop in
about one turn.

It spun down in about one turn when I followed the procedure, and made
no odd noises, so loose spindle bearings do not appear to be a problem.

Hmm ... with a 6" plate instead of 9" you have less flywheel
effect, so I would make the test time about 1/2 turn.

Hmm. Rotational momentum will vary with the moment of rotational
inertia, which will vary as the square of diameter: (6/9)^2= 0.444,
call it one half.

Joe Gwinn

In article ,
Clark Magnuson wrote:

I have a 5914 that shakes hard with a cut off blade.
I am tense, and when the shaking causes something to fall over in the
pan of the lathe, I just about jump out of my skin.

I burned those nerves out long ago.

The cutoff has made sharp bang noises, to the point I thought something
must have broken, but no damage ever found. I think it was passing a
lump of chips, apparently because the tool was cutting on the side
because the toolpost had rotated.

I also had it stall the workpiece in the 3-jaw chuck, which did not
stop. Very dramatic. I backed off, then resumed cutting off. The
workpiece now wobbled a bit, but the cutoff succeeded without further
drama. I must have pushed too hard, but I'm getting the feel.

I buy used tool bits cheap, precisely so I don't need to cry when I
break something. My objective is to not break the lathe, but all else
is open season.


I now hack saw off pieces and then face it with the lathe.

But I'm stubborn, and am using cutoffs as a way to uncover accumulated
problems, so they can be fixed. If the lathe can part off, everything
else will work.

This is an industrial lathe, and would have been laughed off the planet
if it were unable to part off. So if it cannot now do cutoffs,
something is wrong and ought to be fixed.

Joe Gwinn

In article ,
"DoN. Nichols" wrote:

On 2008-04-07, Clark Magnuson wrote:
I have a 5914 that shakes hard with a cut off blade.
I am tense, and when the shaking causes something to fall over in the
pan of the lathe, I just about jump out of my skin.

I have no problems with my Clausing 5418 -- pretty much the same
except step pulley and manual belt changes. I always part of with the
backgear.

I now hack saw off pieces and then face it with the lathe.

Well ... for larger workpieces, I use the 4x6"
horizontal/vertical cheap bandsaw. But I will certainly part off
workpieces which I feed through the spindle -- both up to 1" in the 5C
collets, and the hex 12L14 stock which is the maximum which will fit
through the 1-3/8" ID spindle with the drawtube removed. (I think that
is 1-1/8" hex, but until I have to buy more, it won't matter much.) The
hex stock is held in the 3-jaw chuck.

If I ever do see chatter when parting off, I know that it is
time to tighten the spindle draw-up ring again. (I swapped spindles to
get an L-00 spindle nose in place of the 2-1/4x8 which came with the
lathe.

I thought the spindle was tight enough, but maybe not. The 6" drive
playte should have stopped in a half turn, as discussed elsewhere. I
think I'll revisit this.

Joe Gwinn

In article ,
Gunner Asch wrote:

On Sun, 06 Apr 2008 21:43:27 -0400, Joseph Gwinn
wrote:


Aloris claimed it was not a problem, but I certainly had the problem
with the Dickson toolpost. The Aloris does have a blind ~3/8" diameter
hole in the bottom that appears to be intended to accept an
anti-rotation pin.

I have KDK on all my machines, including the Hardinge HLV-H..and it
will twist if I screw up.

KDK toolposts also have polished bottoms, I assume.

How does KDK compare to Aloris?

Equally good. You will find far far more KDK in commercial shops than
Aloris though, for some reason.

Probably KDK gives a better deal in bulk.


Tighten up the tool post, or put a bit of yellow legal-pad paper
under it.

OK. It was pretty tight. Is yellow legal paper special?

It provides a nice friction surface between the block and the
compound. Even when oily.

Ahh. That was my question.

I use a water-oil emulsion for cutting, and I worried that the water
would turn the paper into mush. Maybe the paper needs to be soaked in
way oil first.

It won't turn into mush when its clamped under the tool holder.

I was also thinking of using electrical "fishpaper" (vulcanized fiber)
in place of the legal paper. Fishpaper is *very* strong. Fish are not
involved; I have no idea where the name came from.

I've also been thinking that the paper might benefit from being sealed
with shellac. Application would be by dipping in shellac diluted with
alcohol.

Try the yellow paper. Ill send you a dollar to buy a pad at the 99c
store. G

The issue is that I don't want to have to keep replacing the "gasket",
mainly because it may become a nuisance when everything is coated with
baby blue emulsion.


And learn to sharpen/setup/line up your cutting tools better. A cut
shouldn't take all that much pressure to accomplish unless they are
dull, or you are feeding way too fast

It was not quite razor sharp, but it wasn't dull either. But it won't
hurt to sharpen it.

I suspect the real problem (aside from the toolpost rotating) was that I
was simply pushing too hard, as I learn the feel of cutting off. This
is the part that must be learned by using the lathe, that cannot be
learned by reading books.

Joe Gwinn

Good thinking and sorta echoed my own thoughts. It takes time to get
a feel, or read the recommended speeds and feeds and set your travel
accordingly.

I tend to make blue chips..push harder than most might, but I know my
machines, my tooling.

Well, I've been managing pale yellow to brown chips mostly, and did
manage blue while doing roughing-cut experiments. This while using
brushed-on black sulfur oil. But since I started using the sprayed
water-oil emulsion, things have been boringly cool, and all chips are
shiney. But the emulsion is baby blue.

Joe Gwinn


Black sulpher oil works good for pipe threading using dies, but not so
great for lathe work. You have to thin it out a bit.

And the best thinner is carbon tetrachloride, with trichloroethylene a
close second?

Joe Gwinn

On Mon, 07 Apr 2008 21:58:26 -0400, Joseph Gwinn
wrote:

In article ,
"DoN. Nichols" wrote:


Hmm ... with a 6" plate instead of 9" you have less flywheel
effect, so I would make the test time about 1/2 turn.

Hmm. Rotational momentum will vary with the moment of rotational
inertia, which will vary as the square of diameter: (6/9)^2= 0.444,
call it one half.


Polar moment of inertia is proportional to the fourth power of the
diameter.

--
Ned Simmons

On Mon, 07 Apr 2008 22:10:04 -0400, Joseph Gwinn
wrote:

In article ,
Clark Magnuson wrote:

I have a 5914 that shakes hard with a cut off blade.
I am tense, and when the shaking causes something to fall over in the
pan of the lathe, I just about jump out of my skin.

I burned those nerves out long ago.

The cutoff has made sharp bang noises, to the point I thought something
must have broken, but no damage ever found. I think it was passing a
lump of chips, apparently because the tool was cutting on the side
because the toolpost had rotated.

The banging noises come from the workpiece loading up, jamming in the
work, then coming free again. Push harder, or a smidge less. Proper
tool nose geometry is essential. grind it in a pickle fork
configuration, with a chip breaker in the middle.
Going in with a flat bladed "chisel" on a smallish lathe is
problematic.

I also had it stall the workpiece in the 3-jaw chuck, which did not
stop. Very dramatic. I backed off, then resumed cutting off. The
workpiece now wobbled a bit, but the cutoff succeeded without further
drama. I must have pushed too hard, but I'm getting the feel.

Check center height. You must be DEAD NUTs and on center.

I buy used tool bits cheap, precisely so I don't need to cry when I
break something. My objective is to not break the lathe, but all else
is open season.


I now hack saw off pieces and then face it with the lathe.

But I'm stubborn, and am using cutoffs as a way to uncover accumulated
problems, so they can be fixed. If the lathe can part off, everything
else will work.

This is an industrial lathe, and would have been laughed off the planet
if it were unable to part off. So if it cannot now do cutoffs,
something is wrong and ought to be fixed.

Joe Gwinn

http://yarchive.net/metal/parting_off.html

From Robert Bastow.

Gunner


"[L]iberals are afraid to state what they truly believe in, for to do so
would result in even less votes than they currently receive. Their
methodology is to lie about their real agenda in the hopes of regaining
power, at which point they will do whatever they damn well please. The
problem is they have concealed and obfuscated for so long that, as a group,
they themselves are no longer sure of their goals. They are a collection of
wild-eyed splinter groups, all holding a grab-bag of dreams and wishes. Some
want a Socialist, secular-humanist state, others the repeal of the Second
Amendment. Some want same sex/different species marriage, others want voting
rights for trees, fish, coal and bugs. Some want cradle to grave care and
complete subservience to the government nanny state, others want a culture
that walks in lockstep and speaks only with intonations of political
correctness. I view the American liberals in much the same way I view the
competing factions of Islamic
fundamentalists. The latter hate each other to the core, and only join
forces to attack the US or Israel. The former hate themselves to the core,
and only join forces to attack George Bush and conservatives." --Ron Marr

On Mon, 07 Apr 2008 22:16:46 -0400, Joseph Gwinn
wrote:

In article ,
Gunner Asch wrote:

On Sun, 06 Apr 2008 21:43:27 -0400, Joseph Gwinn
wrote:


Aloris claimed it was not a problem, but I certainly had the problem
with the Dickson toolpost. The Aloris does have a blind ~3/8" diameter
hole in the bottom that appears to be intended to accept an
anti-rotation pin.

I have KDK on all my machines, including the Hardinge HLV-H..and it
will twist if I screw up.

KDK toolposts also have polished bottoms, I assume.

How does KDK compare to Aloris?

Equally good. You will find far far more KDK in commercial shops than
Aloris though, for some reason.

Probably KDK gives a better deal in bulk.


Tighten up the tool post, or put a bit of yellow legal-pad paper
under it.

OK. It was pretty tight. Is yellow legal paper special?

It provides a nice friction surface between the block and the
compound. Even when oily.

Ahh. That was my question.

I use a water-oil emulsion for cutting, and I worried that the water
would turn the paper into mush. Maybe the paper needs to be soaked in
way oil first.

It won't turn into mush when its clamped under the tool holder.

I was also thinking of using electrical "fishpaper" (vulcanized fiber)
in place of the legal paper. Fishpaper is *very* strong. Fish are not
involved; I have no idea where the name came from.

I've also been thinking that the paper might benefit from being sealed
with shellac. Application would be by dipping in shellac diluted with
alcohol.

Try the yellow paper. Ill send you a dollar to buy a pad at the 99c
store. G

The issue is that I don't want to have to keep replacing the "gasket",
mainly because it may become a nuisance when everything is coated with
baby blue emulsion.

You wont have to replace it very often.



And learn to sharpen/setup/line up your cutting tools better. A cut
shouldn't take all that much pressure to accomplish unless they are
dull, or you are feeding way too fast

It was not quite razor sharp, but it wasn't dull either. But it won't
hurt to sharpen it.

I suspect the real problem (aside from the toolpost rotating) was that I
was simply pushing too hard, as I learn the feel of cutting off. This
is the part that must be learned by using the lathe, that cannot be
learned by reading books.

Joe Gwinn

Good thinking and sorta echoed my own thoughts. It takes time to get
a feel, or read the recommended speeds and feeds and set your travel
accordingly.

I tend to make blue chips..push harder than most might, but I know my
machines, my tooling.

Well, I've been managing pale yellow to brown chips mostly, and did
manage blue while doing roughing-cut experiments. This while using
brushed-on black sulfur oil. But since I started using the sprayed
water-oil emulsion, things have been boringly cool, and all chips are
shiney. But the emulsion is baby blue.

Joe Gwinn


Black sulpher oil works good for pipe threading using dies, but not so
great for lathe work. You have to thin it out a bit.

And the best thinner is carbon tetrachloride, with trichloroethylene a
close second?

No idea.
I use only oil in the lathe, but proper lathe cutting oil, usually
high sulfur, but much thinner. When I run low, I ask a customer for
a few gallons.


Joe Gwinn


"[L]iberals are afraid to state what they truly believe in, for to do so
would result in even less votes than they currently receive. Their
methodology is to lie about their real agenda in the hopes of regaining
power, at which point they will do whatever they damn well please. The
problem is they have concealed and obfuscated for so long that, as a group,
they themselves are no longer sure of their goals. They are a collection of
wild-eyed splinter groups, all holding a grab-bag of dreams and wishes. Some
want a Socialist, secular-humanist state, others the repeal of the Second
Amendment. Some want same sex/different species marriage, others want voting
rights for trees, fish, coal and bugs. Some want cradle to grave care and
complete subservience to the government nanny state, others want a culture
that walks in lockstep and speaks only with intonations of political
correctness. I view the American liberals in much the same way I view the
competing factions of Islamic
fundamentalists. The latter hate each other to the core, and only join
forces to attack the US or Israel. The former hate themselves to the core,
and only join forces to attack George Bush and conservatives." --Ron Marr

In article ,
Gunner Asch wrote:

On Mon, 07 Apr 2008 22:16:46 -0400, Joseph Gwinn
wrote:

In article ,
Gunner Asch wrote:

On Sun, 06 Apr 2008 21:43:27 -0400, Joseph Gwinn
wrote:


[snip]

I use a water-oil emulsion for cutting, and I worried that the water
would turn the paper into mush. Maybe the paper needs to be soaked in
way oil first.

It won't turn into mush when its clamped under the tool holder.

I was also thinking of using electrical "fishpaper" (vulcanized fiber)
in place of the legal paper. Fishpaper is *very* strong. Fish are not
involved; I have no idea where the name came from.

I've also been thinking that the paper might benefit from being sealed
with shellac. Application would be by dipping in shellac diluted with
alcohol.

Try the yellow paper. Ill send you a dollar to buy a pad at the 99c
store. G

The issue is that I don't want to have to keep replacing the "gasket",
mainly because it may become a nuisance when everything is coated with
baby blue emulsion.

You won't have to replace it very often.

I will see how it goes in my shop.


And learn to sharpen/setup/line up your cutting tools better. A cut
shouldn't take all that much pressure to accomplish unless they are
dull, or you are feeding way too fast

It was not quite razor sharp, but it wasn't dull either. But it won't
hurt to sharpen it.

I suspect the real problem (aside from the toolpost rotating) was that
I
was simply pushing too hard, as I learn the feel of cutting off. This
is the part that must be learned by using the lathe, that cannot be
learned by reading books.

Joe Gwinn

Good thinking and sorta echoed my own thoughts. It takes time to get
a feel, or read the recommended speeds and feeds and set your travel
accordingly.

I tend to make blue chips..push harder than most might, but I know my
machines, my tooling.

Well, I've been managing pale yellow to brown chips mostly, and did
manage blue while doing roughing-cut experiments. This while using
brushed-on black sulfur oil. But since I started using the sprayed
water-oil emulsion, things have been boringly cool, and all chips are
shiney. But the emulsion is baby blue.

Joe Gwinn


Black sulpher oil works good for pipe threading using dies, but not so
great for lathe work. You have to thin it out a bit.

And the best thinner is carbon tetrachloride, with trichloroethylene a
close second?

No idea.
I use only oil in the lathe, but proper lathe cutting oil, usually
high sulfur, but much thinner. When I run low, I ask a customer for
a few gallons.

I was kind of pulling your leg. Good luck getting either solvent,
although they would work well. And you would be *very* happy from the
solvent fumes. Till you passed out.

What kind of oil do you use, by make and model?

Joe Gwinn

In article ,
Gunner Asch wrote:

On Mon, 07 Apr 2008 22:10:04 -0400, Joseph Gwinn
wrote:

In article ,
Clark Magnuson wrote:

I have a 5914 that shakes hard with a cut off blade.
I am tense, and when the shaking causes something to fall over in the
pan of the lathe, I just about jump out of my skin.

I burned those nerves out long ago.

The cutoff has made sharp bang noises, to the point I thought something
must have broken, but no damage ever found. I think it was passing a
lump of chips, apparently because the tool was cutting on the side
because the toolpost had rotated.

The banging noises come from the workpiece loading up, jamming in the
work, then coming free again. Push harder, or a smidge less.

That was my guess. The sidewalls of the groove are ragged and galled,
which is a clue.

Need to find the optimum degree of push.


Proper
tool nose geometry is essential. Grind it in a pickle fork
configuration, with a chip breaker in the middle.
Going in with a flat bladed "chisel" on a smallish lathe is
problematic.

The top of the T is scooped, but gently. The blade is 1/8" wide by
11/16" deep. I'll have to try putting a narrow groove in the center,
using a Dremel tool. Need to make sure the center can still cut,
though, as there would otherwise be no place for the resulting disk to
go.

Some of the carbide inserts used for cutting off also have this
geometry. I recall that the Manchester ones do, from the photos in the
J&L catalog.


I also had it stall the workpiece in the 3-jaw chuck, which did not
stop. Very dramatic. I backed off, then resumed cutting off. The
workpiece now wobbled a bit, but the cutoff succeeded without further
drama. I must have pushed too hard, but I'm getting the feel.

Check center height. You must be DEAD NUTs and on center.

It was right on. Think it still is. Will check, though this has not
tended to drift.


I buy used tool bits cheap, precisely so I don't need to cry when I
break something. My objective is to not break the lathe, but all else
is open season.


I now hack saw off pieces and then face it with the lathe.

But I'm stubborn, and am using cutoffs as a way to uncover accumulated
problems, so they can be fixed. If the lathe can part off, everything
else will work.

This is an industrial lathe, and would have been laughed off the planet
if it were unable to part off. So if it cannot now do cutoffs,
something is wrong and ought to be fixed.

Joe Gwinn

http://yarchive.net/metal/parting_off.html

From Robert Bastow.

I'll read it.


Joe Gwinn

In article ,
Ned Simmons wrote:

On Mon, 07 Apr 2008 21:58:26 -0400, Joseph Gwinn
wrote:

In article ,
"DoN. Nichols" wrote:


Hmm ... with a 6" plate instead of 9" you have less flywheel
effect, so I would make the test time about 1/2 turn.

Hmm. Rotational momentum will vary with the moment of rotational
inertia, which will vary as the square of diameter: (6/9)^2= 0.444,
call it one half.


Polar moment of inertia is proportional to the fourth power of the
diameter.

Right. Should have looked it up. It's the contribution of an element
that varies as the square.

Also again looked at the 5914 manual. It is a 6" driving plate that one
uses, not 9". Don't know where the 9" came from. Perhaps somewhere
else in the manual. In any event, I'll go through the spindle bearing
adjustment dance

Joe Gwinn

On Tue, 08 Apr 2008 09:10:13 -0400, Joseph Gwinn
wrote:


And the best thinner is carbon tetrachloride, with trichloroethylene a
close second?

No idea.
I use only oil in the lathe, but proper lathe cutting oil, usually
high sulfur, but much thinner. When I run low, I ask a customer for
a few gallons.

I was kind of pulling your leg.

I figured G

Good luck getting either solvent,
although they would work well. And you would be *very* happy from the
solvent fumes. Till you passed out.

What kind of oil do you use, by make and model?

Whatever I can scrounge from machine shops.

A lot of it is Mobilmet Omicron , used mostly in screw machines for
both cutting oil and lubricant. I think the new name is Mobilmet 404

http://www.mobil.com/USA-English/Lub...Omicron_Nu.asp

I think the last time I got a couple gallons of something a very
bright red, much like ATF, that smells like ATF, from a Swiss house,
and dumped it into the coolant tank with whatever was in there. Works
fine. I didnt bother looking at the drum, but will next time Im in
there. Or I can call them if you need some info.



Joe Gwinn


Gunner


"[L]iberals are afraid to state what they truly believe in, for to do so
would result in even less votes than they currently receive. Their
methodology is to lie about their real agenda in the hopes of regaining
power, at which point they will do whatever they damn well please. The
problem is they have concealed and obfuscated for so long that, as a group,
they themselves are no longer sure of their goals. They are a collection of
wild-eyed splinter groups, all holding a grab-bag of dreams and wishes. Some
want a Socialist, secular-humanist state, others the repeal of the Second
Amendment. Some want same sex/different species marriage, others want voting
rights for trees, fish, coal and bugs. Some want cradle to grave care and
complete subservience to the government nanny state, others want a culture
that walks in lockstep and speaks only with intonations of political
correctness. I view the American liberals in much the same way I view the
competing factions of Islamic
fundamentalists. The latter hate each other to the core, and only join
forces to attack the US or Israel. The former hate themselves to the core,
and only join forces to attack George Bush and conservatives." --Ron Marr

On Tue, 08 Apr 2008 09:21:20 -0400, Joseph Gwinn
wrote:

In article ,
Gunner Asch wrote:

On Mon, 07 Apr 2008 22:10:04 -0400, Joseph Gwinn
wrote:

In article ,
Clark Magnuson wrote:

I have a 5914 that shakes hard with a cut off blade.
I am tense, and when the shaking causes something to fall over in the
pan of the lathe, I just about jump out of my skin.

I burned those nerves out long ago.

The cutoff has made sharp bang noises, to the point I thought something
must have broken, but no damage ever found. I think it was passing a
lump of chips, apparently because the tool was cutting on the side
because the toolpost had rotated.

The banging noises come from the workpiece loading up, jamming in the
work, then coming free again. Push harder, or a smidge less.

That was my guess. The sidewalls of the groove are ragged and galled,
which is a clue.

How much side relief are you grinding in? Should be just a couple
degrees, but you DO need side relief

Need to find the optimum degree of push.
Sometimes spinning faster helps. I part off at about 600- 800 rpm on
stuff under 1"


Proper
tool nose geometry is essential. Grind it in a pickle fork
configuration, with a chip breaker in the middle.
Going in with a flat bladed "chisel" on a smallish lathe is
problematic.

The top of the T is scooped, but gently. The blade is 1/8" wide by
11/16" deep. I'll have to try putting a narrow groove in the center,
using a Dremel tool. Need to make sure the center can still cut,
though, as there would otherwise be no place for the resulting disk to
go.

Some of the carbide inserts used for cutting off also have this
geometry. I recall that the Manchester ones do, from the photos in the
J&L catalog.


I also had it stall the workpiece in the 3-jaw chuck, which did not
stop. Very dramatic. I backed off, then resumed cutting off. The
workpiece now wobbled a bit, but the cutoff succeeded without further
drama. I must have pushed too hard, but I'm getting the feel.

Check center height. You must be DEAD NUTs and on center.

It was right on. Think it still is. Will check, though this has not
tended to drift.


I buy used tool bits cheap, precisely so I don't need to cry when I
break something. My objective is to not break the lathe, but all else
is open season.


I now hack saw off pieces and then face it with the lathe.

But I'm stubborn, and am using cutoffs as a way to uncover accumulated
problems, so they can be fixed. If the lathe can part off, everything
else will work.

This is an industrial lathe, and would have been laughed off the planet
if it were unable to part off. So if it cannot now do cutoffs,
something is wrong and ought to be fixed.

Joe Gwinn

http://yarchive.net/metal/parting_off.html

From Robert Bastow.

I'll read it.


Joe Gwinn


"[L]iberals are afraid to state what they truly believe in, for to do so
would result in even less votes than they currently receive. Their
methodology is to lie about their real agenda in the hopes of regaining
power, at which point they will do whatever they damn well please. The
problem is they have concealed and obfuscated for so long that, as a group,
they themselves are no longer sure of their goals. They are a collection of
wild-eyed splinter groups, all holding a grab-bag of dreams and wishes. Some
want a Socialist, secular-humanist state, others the repeal of the Second
Amendment. Some want same sex/different species marriage, others want voting
rights for trees, fish, coal and bugs. Some want cradle to grave care and
complete subservience to the government nanny state, others want a culture
that walks in lockstep and speaks only with intonations of political
correctness. I view the American liberals in much the same way I view the
competing factions of Islamic
fundamentalists. The latter hate each other to the core, and only join
forces to attack the US or Israel. The former hate themselves to the core,
and only join forces to attack George Bush and conservatives." --Ron Marr

On 2008-04-08, Joseph Gwinn wrote:
In article ,
"DoN. Nichols" wrote:

On 2008-04-06, Joseph Gwinn wrote:

[ ... ]

Man does Kennametal have a big catalog. What I didn't see was a
comparison of the advantages and disadvantages of the various methods of
holding inserts.

Typically, I think that you pick a system which matches what you
already have. At least that is what I did -- starting with a couple of
good holder from eBay auctions along with 100 matching inserts for each. :-)

I'm leaning towards buying new, not wanting to wait a year to get lucky.
Now you know that the day after I order the new item, three fine used
items will turn up on eBay, for a third the price.

O.K. That will get you started anyway. :-) My preference
(starting new) would be to get the BXA-16N (negative rake) with
positive/negative inserts for it, and then get the straight pointed ones
(and perhaps other tools) for the same inserts. You'll need something
different for threading inserts anyway. For those, I prefer the laydown
tools to the stand-up ones -- easier to adjust for pitch angle with
anvils.

Enjoy,
DoN.

--
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