This is driving me crazy. I've tried everything I can think of.

-Centre height OK.
-Blade not overextended.
-Insert OK
-Coolant on
-Reduced speed, increased feed
-Adjusted backlash on cross slide to minimum
-Saddle clamped
-Happens with different materials, and diameters

But I can't eliminate the vibration. It is really heavy, and is
causing clamping screws and the like to loosen.

It's making me feel like a complete idiot. I should be able to solve
this problem, but what's causing it?

Any suggestions, or should I just go and slash my wrists now?! g

Cheers, Dom.

Dom wrote:
This is driving me crazy. I've tried everything I can think of.

-Centre height OK.
-Blade not overextended.
-Insert OK
-Coolant on
-Reduced speed, increased feed
-Adjusted backlash on cross slide to minimum
-Saddle clamped
-Happens with different materials, and diameters

But I can't eliminate the vibration. It is really heavy, and is
causing clamping screws and the like to loosen.

It's making me feel like a complete idiot. I should be able to solve
this problem, but what's causing it?

Any suggestions, or should I just go and slash my wrists now?! g

Cheers, Dom.


Well, I used to have a light lathe (Atlas 10", then a Craftsman 12") and
had a lot of the same problems. Making things more rigid helped, up to
a point. Making sure the cutting tip is as close to being over the
compound swivel helps a lot, too. If you have a "lantern" type
toolpost, that cn become quite flexible.



Reducing speed may be counterproductive. You definitely want to keep
the feed steady, but sometimes speeding up and keeping the cut moderate
to prevent overloading the motor is helpful.



Now that I have a 3500-Lb 15" Sheldon, I don't have these problems at
all, using essentially the same techniques. So, it has to be rigidity
of the machine. If flexibility of the lathes's spindle or bed is the
limit, then nothing you can do outside changing the whole lathe will fix
it. I have seen pictures of "gooseneck" tool holders that were designed
to flex AWAY from the cut, preventing the chatter from building to
enormous amplitude. Other than surfing eBay, I have no idea where to
get such a thing today.



Jon

"Dom" wrote in message
oups.com...
This is driving me crazy. I've tried everything I can think of.

-Centre height OK.
-Blade not overextended.
-Insert OK
-Coolant on
-Reduced speed, increased feed
-Adjusted backlash on cross slide to minimum
-Saddle clamped
-Happens with different materials, and diameters

But I can't eliminate the vibration. It is really heavy, and is
causing clamping screws and the like to loosen.

It's making me feel like a complete idiot. I should be able to solve
this problem, but what's causing it?

Any suggestions, or should I just go and slash my wrists now?! g

Cheers, Dom.


Been there, done that...

This may not be correct, but I found that grinding the cutoff tool
to put a chip-breaker in the top surface solves the problem. It
seems to me that expecting the chip to make an abrupt right angle
turn the instant it gets cut off is asking a bit much... So, I grind
the tool such that the top of the cutting edge, instead of being
perpendicular to the tangent of the surface to be cut, it is at more
like 45 degrees or so.

Oh, and sometimes when parting a large piece of work, it helps
to make two cuts. Go in a ways, back out, move the lathe carriage
20 thou or so, and go back in. Cutting in "steps" like this keeps
the tool from binding up in the slot it just cut and also it is more
tolerant of the tool being aligned slightly off perpendicular to the
axis of the work.

Jerry

This is driving me crazy. I've tried everything I can think of.

BTDT.

The solution is insert style cutoff tool. I made the change and all my
troubles went away. Just engage the power X feed and collect your part. I
use manchester separator system, there are other good choices, especially
iscar.

Karl

On Oct 30, 3:37 pm, Jon Elson wrote:
Dom wrote:
This is driving me crazy. I've tried everything I can think of.

-Centre height OK.
-Blade not overextended.
-Insert OK
-Coolant on
-Reduced speed, increased feed
-Adjusted backlash on cross slide to minimum
-Saddle clamped
-Happens with different materials, and diameters

But I can't eliminate the vibration. It is really heavy, and is
causing clamping screws and the like to loosen.

It's making me feel like a complete idiot. I should be able to solve
this problem, but what's causing it?

Any suggestions, or should I just go and slash my wrists now?! g

Cheers, Dom.

Well, I used to have a light lathe (Atlas 10", then a Craftsman 12") and
had a lot of the same problems. Making things more rigid helped, up to
a point. Making sure the cutting tip is as close to being over the
compound swivel helps a lot, too. If you have a "lantern" type
toolpost, that cn become quite flexible.

Reducing speed may be counterproductive. You definitely want to keep
the feed steady, but sometimes speeding up and keeping the cut moderate
to prevent overloading the motor is helpful.

Now that I have a 3500-Lb 15" Sheldon, I don't have these problems at
all, using essentially the same techniques. So, it has to be rigidity
of the machine. If flexibility of the lathes's spindle or bed is the
limit, then nothing you can do outside changing the whole lathe will fix
it. I have seen pictures of "gooseneck" tool holders that were designed
to flex AWAY from the cut, preventing the chatter from building to
enormous amplitude. Other than surfing eBay, I have no idea where to
get such a thing today.

Jon

I watched my 10X24 Jet lathe walk on the floor since 1976. Then last
year I bolted it too a 2 inch thick steel plate, now it will cutoff
without chatter. I was told to also make a very heavy stand with 4
inch square tubes, and bolt to the floor. Have not done this but will
in the future. currently it is on a HF sheet metal stand intended for
a 12X36 lathe. Not bolted down, but leveled.

I also have a 5000 lb. 18X40 lathe, and it will break tooling before
it ever chatters. Let me tell you, the D size quick change was never
intended to work with this beast, I've several times now have seen the
fine adjust screw bend, and the tooling slide down on the dove tail.
You really have to over tighten the wedge clamp, especially when
making gouging cuts into the end of a solid round. I was trying to
make a large (4 inch) piston at the time, gouging out where the crank
would be. Not making killer cuts.

Ignator

My little South Bend 9" really struggled doing parting. I tried lots of
ways of sharpening HSS, tried insert cutoff holders in various widths,
tried tightening every gib until I could barely move anything. Of course,
I tried to always reduce overhang and vary speeds, and tried constant oil
drips, dry, you name it. Nothing worked well at all. Then I got two kits
from MLA. The first was a T-slot cross-slide, and the second was the rear
parting tool. With a parting tool mounted upside down in the rear, it
works really really a whole lot better. That's a good solution for a
small (8-12") lathe.

GWE

On Oct 30, 2:16 pm, Dom wrote:
... It is really heavy, and is
causing clamping screws and the like to loosen.



Wow, that's chatter. Makes me think it's not technique rather
something in the setup of the lathe. What size lathe? Belt or
geared? Back gear in? Bolted to floor? What style chuck? How old?

On Tue, 30 Oct 2007 14:16:05 -0700, Dom
wrote:

This is driving me crazy. I've tried everything I can think of.

-Centre height OK.
-Blade not overextended.
-Insert OK
-Coolant on
-Reduced speed, increased feed
-Adjusted backlash on cross slide to minimum
-Saddle clamped
-Happens with different materials, and diameters

But I can't eliminate the vibration. It is really heavy, and is
causing clamping screws and the like to loosen.

It's making me feel like a complete idiot. I should be able to solve
this problem, but what's causing it?

Any suggestions, or should I just go and slash my wrists now?! g

Cheers, Dom.

Novel solution, might be worth a try. Flood lubricant of arterial
blood might work, and it'd surely deal with the frustration.

Even better, if you're in Texas, might be to catch a nocturnal thief
and slash his wrists. Then you could report on the efficacy of the
cutting fluid.

On Tue, 30 Oct 2007 17:59:18 -0500, "Karl Townsend"
wrote:



This is driving me crazy. I've tried everything I can think of.

BTDT.

The solution is insert style cutoff tool. I made the change and all my
troubles went away. Just engage the power X feed and collect your part. I
use manchester separator system, there are other good choices, especially
iscar.

Karl

I respectfully disagree. I think the issue is rigidity of the machine.
I've had zero problems with cutoff or chatter using ordinary HSS
parting blades on my import (India, not China) 15x50 lathe.

Carbide tooling always requires a more rigid machine than well-ground
HSS tooling to work well.

Dom wrote:

Any suggestions, or should I just go and slash my wrists now?! g

Clapper in the spindle bearing?


Nick
--
The lowcost-DRO:
http://www.yadro.de

Don Foreman wrote:

On Tue, 30 Oct 2007 17:59:18 -0500, "Karl Townsend"
wrote:



This is driving me crazy. I've tried everything I can think of.

BTDT.

The solution is insert style cutoff tool. I made the change and all my
troubles went away. Just engage the power X feed and collect your part. I
use manchester separator system, there are other good choices, especially
iscar.

Karl


I respectfully disagree. I think the issue is rigidity of the machine.
I've had zero problems with cutoff or chatter using ordinary HSS
parting blades on my import (India, not China) 15x50 lathe.

Carbide tooling always requires a more rigid machine than well-ground
HSS tooling to work well.

Amen!

Insert tips, at a couple to ten bucks each, have a REALLY short
lifespan under contitions of extreme flex and movement.

Sometimes the answer is a thinner cutoff tool, sometimes the answer is
to go balls to the wall, and run the lathe at the verge of stalling the
motor.

I have seen, but not used, setups with a block of material under the
tool, supporting it against the forces of the cut.

Sometimes, supporting the end of the work with a steady or a center
rest is a help. Let off the pressure once the cut is nearing center, or
it eats your tool. :-)

If available, I use the power cross feed to part with. Cuts down on
opportunities to waffle, and it does not let up on the cut. More often
than not, I have found that the apprentices in out shop are unwilling to
make the tool work, and it skips and drags across the surface until it
won't ever cut.

Cheers
Trevor Jones

On Wed, 31 Oct 2007 01:11:36 -0600, with neither quill nor qualm, Don
Foreman quickly quoth:

On Tue, 30 Oct 2007 14:16:05 -0700, Dom
wrote:

This is driving me crazy. I've tried everything I can think of.

-Centre height OK.
-Blade not overextended.
-Insert OK
-Coolant on
-Reduced speed, increased feed
-Adjusted backlash on cross slide to minimum
-Saddle clamped
-Happens with different materials, and diameters

But I can't eliminate the vibration. It is really heavy, and is
causing clamping screws and the like to loosen.

It's making me feel like a complete idiot. I should be able to solve
this problem, but what's causing it?

Any suggestions, or should I just go and slash my wrists now?! g

Cheers, Dom.

Novel solution, might be worth a try. Flood lubricant of arterial
blood might work, and it'd surely deal with the frustration.

Even better, if you're in Texas, might be to catch a nocturnal thief
and slash his wrists. Then you could report on the efficacy of the
cutting fluid.

2 Points, DoN!

--
Knowledge and timber shouldn't be much used till they are seasoned.
-- Oliver Wendell Holmes

Hmm...

Looks like I have the minority view here. You make good points.

For my lathe (10EE), I had awful time with cutoff with HSS tooling on
anything over one inch diameter. Tried everything. "The Kid" made me get an
insert cutoff tool and use power feed and lots o' coolant. Viola! my
troubles went away. YMMV

Karl

On Wed, 31 Oct 2007 10:04:19 -0500, "Karl Townsend"
wrote:

Hmm...

Looks like I have the minority view here. You make good points.

For my lathe (10EE), I had awful time with cutoff with HSS tooling on
anything over one inch diameter. Tried everything. "The Kid" made me get an
insert cutoff tool and use power feed and lots o' coolant. Viola! my
troubles went away. YMMV

Karl



I also get on much better with carbide inserts than with HSS blade tools on
the ML7. Partly because of the more consistent chip breaker form and partly
because the holders are about 15 times as stiff.

The Myford doesn't have power cross feed, but I try to keep up a consistent
feed. I do not run the inserts at anywhere near the recommended speeds and
feeds (350sfm and 0.004"/rev) because the lathe just hasn't got the power to
do it.

I do use back gear to give me as much torque as is possible and control the
feed so that the motor doesn't bog down. Stalling the work invariably ends up
in a chipped insert. Not using backgear leads to chatter and chipped inserts,
since there isn't enough torque to keep the tool working. The insert needs to
be about 3-5 thou above centre and with no possibility of the work riding up
over it when getting to the centre of the cut, otherwise that wrecks the
inserts as well.


As a datum, I don't have problems parting off 4" 4340 with a 7" lathe and
1/2hp motor

Mark Rand
RTFM

Dom wrote:
This is driving me crazy. I've tried everything I can think of.

-Centre height OK.
-Blade not overextended.
-Insert OK
-Coolant on
-Reduced speed, increased feed
-Adjusted backlash on cross slide to minimum
-Saddle clamped
-Happens with different materials, and diameters

But I can't eliminate the vibration. It is really heavy, and is
causing clamping screws and the like to loosen.

It's making me feel like a complete idiot. I should be able to solve
this problem, but what's causing it?

Any suggestions, or should I just go and slash my wrists now?! g

Cheers, Dom.

I had a similar problem on a 5" CH (10" swing) Boxford. In desperation I
eventually tried levering the spindle up and, to my horror, found there
was movement - the bolts holding the headstock to the bed were a little
loose. After tightening the problem went away.
Far fetched? Yes, but you never know...

--
Regards, Gary Wooding
(To reply by email, change feet to foot in my address)

--
Posted via a free Usenet account from http://www.teranews.com

Don Foreman wrote:
On Tue, 30 Oct 2007 14:16:05 -0700, Dom
wrote:


This is driving me crazy. I've tried everything I can think of.

-Centre height OK.
-Blade not overextended.
-Insert OK
-Coolant on
-Reduced speed, increased feed
-Adjusted backlash on cross slide to minimum
-Saddle clamped
-Happens with different materials, and diameters

But I can't eliminate the vibration. It is really heavy, and is
causing clamping screws and the like to loosen.

It's making me feel like a complete idiot. I should be able to solve
this problem, but what's causing it?

Any suggestions, or should I just go and slash my wrists now?! g

Cheers, Dom.


Novel solution, might be worth a try. Flood lubricant of arterial
blood might work, and it'd surely deal with the frustration.


GAWWD, no, don't do that! Have you ever seen how badly blood rusts fine
metal?

Jon (Who has accidentally spilled blood on his lathe once or twice)

lemel_man wrote:
Dom wrote:

This is driving me crazy. I've tried everything I can think of.

-Centre height OK.
-Blade not overextended.
-Insert OK
-Coolant on
-Reduced speed, increased feed
-Adjusted backlash on cross slide to minimum
-Saddle clamped
-Happens with different materials, and diameters

But I can't eliminate the vibration. It is really heavy, and is
causing clamping screws and the like to loosen.

It's making me feel like a complete idiot. I should be able to solve
this problem, but what's causing it?

Any suggestions, or should I just go and slash my wrists now?! g

Cheers, Dom.

I had a similar problem on a 5" CH (10" swing) Boxford. In desperation I
eventually tried levering the spindle up and, to my horror, found there
was movement - the bolts holding the headstock to the bed were a little
loose. After tightening the problem went away.
Far fetched? Yes, but you never know...


Somebody obviously had that headstock off in the past. Any looseness,
anywhere in the entire lathe, will show up when parting off. A really
common one on the lighter lathes is lifting up of the carriage off the
bed. You can just drive a toolholder into the side of the chuck or
workpiece with the lathe off (using the crossfeed), and look for a
change in the fillet of oil between the carriage and ways. If you see
it, you want to work on the gibs under the carriage to remove as much
slack as possible. If you can get the carriage to lift off the ways
during a parting-off cut, the vibration will be scary!

Jon

lemel_man wrote:
Dom wrote:

This is driving me crazy. I've tried everything I can think of.
Oh, one other place to look! Worn chuck jaws! Clamp something very round,
hard and free of taper, like a drill bit or end mill shank in the chuck.
See if you can slip a piece of paper between the round and the jaws.
The farther in you can slip the paper, the worse the problem is, as the
jaws are not holding the workpiece all the way out to the tip. That
allows the work to flex.

If you have this problem, you need to re-grind the chuck jaws.
There should be a procedure on file in the Atlas-Craftsman Yahoo group
http://groups.yahoo.com/group/atlas_craftsman/
(Yahoo's ability to search the archives is horrible, though.)

Jon

Easy solution. I just had to grow some balls. I was a little shy
about breaking the tool, and this led me to taking too light a feed.
I discussed the problem with a colleague, (who happens to be a
national workskills champion) and we had some fun experimenting. He
really carved into it, hand feeding, really heavy cuts, you could hear
the motor loading up, no chatter though, and a beautiful finish. We
tried power feed too, this was maybe a little too slow, and could have
been increased at least double. We tried some 1020, 4140, and 316,
all with no problems. 316 gave the best finish. 4140 had the
cleanest chip.

Thanks all for your input. (I did a follow up post yesterday, but its
not here?) Its been interesting getting other peoples take on the
subject.

Cheers Dom.
(Queensland Australia)

Karl Townsend wrote:

Hmm...

Looks like I have the minority view here. You make good points.

For my lathe (10EE), I had awful time with cutoff with HSS tooling on
anything over one inch diameter. Tried everything. "The Kid" made me get an
insert cutoff tool and use power feed and lots o' coolant. Viola! my
troubles went away. YMMV

Karl

Did you try the "power feed and lots o' coolant" with the HSS tools??
...lew...

Keywords:
In article s.com, "Karl Townsend" wrote:
Hmm...

Looks like I have the minority view here. You make good points.

For my lathe (10EE), I had awful time with cutoff with HSS tooling on
anything over one inch diameter. Tried everything. "The Kid" made me get an
insert cutoff tool and use power feed and lots o' coolant. Viola! my
troubles went away. YMMV

A 10EE is probably an order of magnitude stiffer than a lot of the
ancient South Bends & the like that most home shops have. I have a
relatively new 11" Emco Maier, and it will work with inserts, but only if
you are careful. If you aren't, things can start flexing & exploding in
a hurry.

Doug White

Did you try the "power feed and lots o' coolant" with the HSS tools??

Don't think it would work anywhere near as well. The carbide insert has a
molded chip breaker that pulls the chip in from the side walls so they flow
out well. I seem to remember a sickening crunch and broken tool when the
chips bound up in the HSS cutoff tool.

Karl

Follow Up:

Lathe is a Kirloskar 400. Geared Head. 400mm Swing. 1000mm Between
centres. 3.7kw (5hp) Approx. 10 years old. Its still in excellent
condition. Hardly any wear in the bed. It isn't bolted down, but
weighs 1200kg. (2640 lbs). I guess if it was bolted down, it might
eliminate some of the vibration.

The chucks we use are a 3 jaw and 4 jaw self centering Tos, and 4 jaw
independant Tos. Same results on all.

Parting tools are Sandvik. Bought a new blade about three months ago.

"This may not be correct, but I found that grinding the cutoff tool
to put a chip-breaker in the top surface solves the problem."

Sandvik tools have chip breaker incorporated into them. Not really
having problems forming a chip.

Could the preload on the spindle bearings need adjustment? I was just
reading the manual, and it does discuss adjusting the preload. I also
seem to be having a little trouble getting a nice finish when facing
off. Axially it seems to be very accurate, better than .01mm and
radially it doesn't seem to be too bad, but the only operations that
apply a radial load are parting and facing.

I haven't tried engaging the cross slide feed, maybe I'll do a test
like this and see what happens. I have noticed that the tool seems to
get pulled in almost as though it is not feeding fast enough. I have
a box with all the crashed and broken tools next to the workshop door
to remind me of my mistakes and keep me honest. There is still some
room in it, so I'll get stuck in and see what happens.

Thanks all for your quick responses.

Dom.

Karl Townsend wrote:
Hmm...

Looks like I have the minority view here. You make good points.

For my lathe (10EE), I had awful time with cutoff with HSS tooling on
anything over one inch diameter. Tried everything. "The Kid" made me get an
insert cutoff tool and use power feed and lots o' coolant. Viola! my
troubles went away. YMMV

Karl


I have parted off 3 inch bar on my Myford.

You gotta beleive me, when I say "It ain't a pretty scene"

Finding the balance between too high an RPM, and too much feed...

It cut off, though! :-)

The lathes at work, with power cross feed, are much more fun.

Cheers
Trevor Jones

"Dom" wrote in message
oups.com...
This is driving me crazy. I've tried everything I can think of.

-Centre height OK.
-Blade not overextended.
-Insert OK
-Coolant on
-Reduced speed, increased feed
-Adjusted backlash on cross slide to minimum
-Saddle clamped
-Happens with different materials, and diameters

But I can't eliminate the vibration. It is really heavy, and is
causing clamping screws and the like to loosen.

It's making me feel like a complete idiot. I should be able to solve
this problem, but what's causing it?

Any suggestions, or should I just go and slash my wrists now?! g

Cheers, Dom.

"Dom" wrote in message
oups.com...
This is driving me crazy. I've tried everything I can think of.

-Centre height OK.
-Blade not overextended.
-Insert OK
-Coolant on
-Reduced speed, increased feed
-Adjusted backlash on cross slide to minimum
-Saddle clamped
-Happens with different materials, and diameters

But I can't eliminate the vibration. It is really heavy, and is
causing clamping screws and the like to loosen.

It's making me feel like a complete idiot. I should be able to solve
this problem, but what's causing it?

Any suggestions, or should I just go and slash my wrists now?! g

Cheers, Dom.


A. Bandsaw
B. Burry chicken guts during a full moon.
C. Run the tool upside down.
D. Bandsaw

Karl Townsend wrote:

Did you try the "power feed and lots o' coolant" with the HSS tools??

Don't think it would work anywhere near as well.

I do have and use both HSS and carbide insert parting off tools.
They both have their fields where they outperform the other. It is not HSS
or carbide, it is *when* to use which one.

I prefer the HSS for delicate work, because it has less cutting forces.
What "delicate work" is, is up to you to find out. For me, it is below
about 20mm diameter. A HSS-blade 2mm wide can do up to 50mm diam. on free
cutting steel in one pass with power feed. Needs coolant, is getting
interesting. :-) In almost pure Al, I wouldn't even try it with that setup.

To those who pray the carbide insert parting off tools and damn the HSS:
Just try to part off some 10 x 0.5mm brass tube.


Nick
--
The lowcost-DRO:
http://www.yadro.de

Jon Elson wrote:

GAWWD, no, don't do that! Have you ever seen how badly blood rusts fine
metal?

Is it from the hemoglobin?

Wes

Dom wrote:
Easy solution. I just had to grow some balls. I was a little shy
about breaking the tool, and this led me to taking too light a feed.
I discussed the problem with a colleague, (who happens to be a
national workskills champion) and we had some fun experimenting. He
really carved into it, hand feeding, really heavy cuts, you could hear
the motor loading up, no chatter though, and a beautiful finish. We
tried power feed too, this was maybe a little too slow, and could have
been increased at least double. We tried some 1020, 4140, and 316,
all with no problems. 316 gave the best finish. 4140 had the
cleanest chip.
Great, glad you found the solution. I saw our machinist at work
doing some parting off on a whole bunch of 4" discs on the 20"
Harrison we have. He was running at maybe 180 RPM, and feeding
at about .050" radius per turn! This was in aluminum.

The problems I had on my previous lathes were real problems in
the lathe, I think. I found aluminum even worse than steel, the
chips would bind in the cut.

Jon

According to Dom :
This is driving me crazy. I've tried everything I can think of.

-Centre height OK.
-Blade not overextended.
-Insert OK
-Coolant on
-Reduced speed, increased feed
-Adjusted backlash on cross slide to minimum
-Saddle clamped
-Happens with different materials, and diameters

But I can't eliminate the vibration. It is really heavy, and is
causing clamping screws and the like to loosen.

Have you sharpened the parting blade? Does it have enough end
clearance?

Hmm ... what kind of bearings do you have in your headstock?
Plain bearings with shim adjustment? If so, you need to check for
looseness and take out shims until it is tight enough. (Your spindle is
lifting during the cuts.)

If it is roller bearings, is there a chance that the ring at the
back of the spindle which draws in the bearings tight has loosened so
there is end play in the spindle as well as vertical?

It's making me feel like a complete idiot. I should be able to solve
this problem, but what's causing it?

You checked almost everything else, so I would bet on play in
the spindle. Clamp the chuck on a bar, then try lifting and pressing
down on it while measuring the motion of the spindle.

Oh yes -- one other possibility -- have the jaws of the chuck
worn bell-mouthed, so it is only gripping tight towards the back of the
jaws? If so, perhaps it is time for new jaws, or to mount a set of soft
top-jaws and bore them to near the size of the workpiece so you no
longer have a bell-mouthed set of jaws.

Any suggestions, or should I just go and slash my wrists now?! g

Oh -- slash the wrist with the handle on the carriage handwheel.
That should be dull enough so you'll have time to think of other things
to check before you get through the skin. :-)

Good Luck,
DoN.

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

According to Larry Jaques :
On Wed, 31 Oct 2007 01:11:36 -0600, with neither quill nor qualm, Don
Foreman quickly quoth:

On Tue, 30 Oct 2007 14:16:05 -0700, Dom
wrote:

This is driving me crazy. I've tried everything I can think of.

[ ... ]

Any suggestions, or should I just go and slash my wrists now?! g

Cheers, Dom.

Novel solution, might be worth a try. Flood lubricant of arterial
blood might work, and it'd surely deal with the frustration.

Even better, if you're in Texas, might be to catch a nocturnal thief
and slash his wrists. Then you could report on the efficacy of the
cutting fluid.

2 Points, DoN!

You're giving credit to the wrong Don. I can't claim it. That
was Don Foreman, not me "DoN." is "(Do)nald (N)ichols." run together --
and treat the 'o' as an open '.' so it is also "D.N.". :-)

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 2 Nov 2007 05:39:43 GMT, with neither quill nor qualm,
(DoN. Nichols) quickly quoth:

According to Larry Jaques :
On Wed, 31 Oct 2007 01:11:36 -0600, with neither quill nor qualm, Don
Foreman quickly quoth:

On Tue, 30 Oct 2007 14:16:05 -0700, Dom
wrote:

This is driving me crazy. I've tried everything I can think of.

[ ... ]

Any suggestions, or should I just go and slash my wrists now?! g

Cheers, Dom.

Novel solution, might be worth a try. Flood lubricant of arterial
blood might work, and it'd surely deal with the frustration.

Even better, if you're in Texas, might be to catch a nocturnal thief
and slash his wrists. Then you could report on the efficacy of the
cutting fluid.

2 Points, DoN!

You're giving credit to the wrong Don. I can't claim it. That
was Don Foreman, not me "DoN." is "(Do)nald (N)ichols." run together --
and treat the 'o' as an open '.' so it is also "D.N.". :-)

Apologies to boafaya. I winced 2 seconds after hitting SEND, not that
it did any good.

--
Knowledge and timber shouldn't be much used till they are seasoned.
-- Oliver Wendell Holmes

Wes wrote:
Jon Elson wrote:


GAWWD, no, don't do that! Have you ever seen how badly blood rusts fine
metal?


Is it from the hemoglobin?

Wes

Can't be, that stuff is mostly iron. I think it is just the salts in
the plasma. You've got table salt, potassium, calcium, etc. chlorides
and other salts all in there.

Jon

On Wed, 31 Oct 2007 15:03:49 -0700, Dom wrote:

Easy solution. I just had to grow some balls. I was a little shy
about breaking the tool, and this led me to taking too light a feed.
I discussed the problem with a colleague, (who happens to be a
national workskills champion) and we had some fun experimenting. He
really carved into it, hand feeding, really heavy cuts, you could hear
the motor loading up, no chatter though, and a beautiful finish. We
tried power feed too, this was maybe a little too slow, and could have
been increased at least double. We tried some 1020, 4140, and 316,
all with no problems. 316 gave the best finish. 4140 had the
cleanest chip.

Thanks all for your input. (I did a follow up post yesterday, but its
not here?) Its been interesting getting other peoples take on the
subject.

Cheers Dom.
(Queensland Australia)


I would suggest that it is still worth looking for play in the chuck/headstock
bearings/apron. A tight lathe will take very thin cuts with a parting tool
without chatter. You have got around some play somewhere in the system by
loading the tool up, but you will still have the same problems when it comes
to light facing cuts.

Have a good one

Mark Rand
RTFM

According to Larry Jaques :
On 2 Nov 2007 05:39:43 GMT, with neither quill nor qualm,
(DoN. Nichols) quickly quoth:

According to Larry Jaques :
[ ... ]

2 Points, DoN!

You're giving credit to the wrong Don. I can't claim it. That
was Don Foreman, not me "DoN." is "(Do)nald (N)ichols." run together --
and treat the 'o' as an open '.' so it is also "D.N.". :-)

Apologies to boafaya. I winced 2 seconds after hitting SEND, not that
it did any good.

Well ... I am not offended by being mixed up with the other Don,
and hopefully neither is he.

But you mean that your newsreader doesn't have a wince-sensing
auto-cancel feature? :-)

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 3 Nov 2007 03:54:16 GMT, with neither quill nor qualm,
(DoN. Nichols) quickly quoth:

According to Larry Jaques :
On 2 Nov 2007 05:39:43 GMT, with neither quill nor qualm,
(DoN. Nichols) quickly quoth:

According to Larry Jaques :
[ ... ]

2 Points, DoN!

You're giving credit to the wrong Don. I can't claim it. That
was Don Foreman, not me "DoN." is "(Do)nald (N)ichols." run together --
and treat the 'o' as an open '.' so it is also "D.N.". :-)

Apologies to boafaya. I winced 2 seconds after hitting SEND, not that
it did any good.

Well ... I am not offended by being mixed up with the other Don,
and hopefully neither is he.

I look forward to reading both of youse guys, so that's good.


But you mean that your newsreader doesn't have a wince-sensing
auto-cancel feature? :-)

No, and I've sent in dozens of new-feature requests to Forte about it
already. I can live without that, but I really need a twit filter
which catches every message of the trolls or messages quoting the
trolls. A full-text search would do that and help us clean up the
cliffy/TMT, etc. crap instantly.

--
************************************************** *********
"Boy, I feel safer now that Martha Stewart is behind bars!
O.J. is walking around free, Osama Bin Laden too, but they
take the one woman in America willing to cook and clean
and work in the yard and haul her ass to jail."
--Tim Allen
************************************************** *********

According to Larry Jaques :
On 3 Nov 2007 03:54:16 GMT, with neither quill nor qualm,
(DoN. Nichols) quickly quoth:

[ ... ]

But you mean that your newsreader doesn't have a wince-sensing
auto-cancel feature? :-)

No, and I've sent in dozens of new-feature requests to Forte about it
already. I can live without that, but I really need a twit filter
which catches every message of the trolls or messages quoting the
trolls. A full-text search would do that and help us clean up the
cliffy/TMT, etc. crap instantly.

Mine will do that -- but it puts a lot of load on the net
connection, because it has to read the entire article to catch the
references. While I was running my own (local) news server, the
overhead was minimal, but since I have been forced to go to a remote
news server (by my original ISP first dropping newsfeeds to customers,
and shortly afterwards dropping *all* news servers -- so I dropped
them.)

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 Oct 31, 8:00 pm, Dom wrote:
... It isn't bolted down, but weighs 1200kg. (2640 lbs). I guess if it was bolted down, it might
eliminate some of the vibration.


Doesn't matter how much it weighs; the headstock needs to be bolted
down. Sounds like a nice lathe though, get 'er bolted down and you
should be able to get real nice finishes with some heavy cuts.



Could the preload on the spindle bearings need adjustment?

Get her bolted down first.

I also seem to be having a little trouble getting a nice finish when facing
off.

Lock the carriage and set DOC with the cross-slide. Feed from the
center out. Bolt the headstock down.


I haven't tried engaging the cross slide feed, ...

Try power feed from the center out. You'll love the results.

Oh, and did I say: Bolt the headstock down!

ok, now I am confused - it's not me that started this, but what do you mean
"bolt the head stock down" - are you suggesting that the headstock may be
loose from the ways? or are you suggesting something else? I'm not all
that experienced here, so maybe there is some thing obvious that I don't
understand, but on my lathe at least, the headstock assembly is bolted to
the ways and that whole mess sits on a stand that sits on the floor - so I
could understand "bolt it to the floor", but that doesn't directly affect
the headstock, right?

what am I missing here ---- just trying to learn


wrote in message
oups.com...
On Oct 31, 8:00 pm, Dom wrote:
... It isn't bolted down, but weighs 1200kg. (2640 lbs). I guess if it
was bolted down, it might
eliminate some of the vibration.


Doesn't matter how much it weighs; the headstock needs to be bolted
down. Sounds like a nice lathe though, get 'er bolted down and you
should be able to get real nice finishes with some heavy cuts.



Could the preload on the spindle bearings need adjustment?

Get her bolted down first.

I also seem to be having a little trouble getting a nice finish when
facing
off.

Lock the carriage and set DOC with the cross-slide. Feed from the
center out. Bolt the headstock down.


I haven't tried engaging the cross slide feed, ...

Try power feed from the center out. You'll love the results.

Oh, and did I say: Bolt the headstock down!





--
Posted via a free Usenet account from http://www.teranews.com

wrote:
On Oct 31, 8:00 pm, Dom wrote:

... It isn't bolted down, but weighs 1200kg. (2640 lbs). I guess if it was bolted down, it might
eliminate some of the vibration.



Doesn't matter how much it weighs; the headstock needs to be bolted
down. Sounds like a nice lathe though, get 'er bolted down and you
should be able to get real nice finishes with some heavy cuts.
I have a 3500 Lb Sheldon 15" lathe, and it is performing
PERFECTLY, and on truly amazing cuts, too. It has an 8-point
foot system, but is not bolted down. it is sitting on a typical
home basement concrete floor slab. The manual recomends bolting
to the floor, but I don't want to drill big holes and set
anchors. If the machine's feet are not properly adjusted so
that the machine can rock, that could be a small part of the
problem. But, something else is wrong. I wish I could be there
to see what you are doing. It could be material, it could be a
problem with the machine, it could be technique (tool height,
tool geometry, speed, feed, tool holding, and on and on.)

I used to have a lot of trouble parting off on my Atlas lathes,
but the Sheldon does it like it was nothing. I did grind a
groove doen the center of the parting-off blade, parallel to the
length of the blade. (I only made the groove 1/8" long or
something, it will have to be extended as the blade is
resharpened.) The idea is to make the chip curl inwards a
little as the chip is formed, thereby making it narrower than
the cut in the stock. It works quite well, and prevents the
chips from binding in the cut.

I still try to keep the center of the compound pretty much under
the work to avoid a bending moment on the compound rest, even
though that is quite massive on the Sheldon.

The other thing I wonder about is the chuck. If the jaws are
not gripping well out at the tips, then you have a flexible bar
that you are trying to cut at a distance from where it is
actually being held by the chuck. Also, you can check with a
dial indicator to see if the chuck is not mounted securely.
What is the chuck mount? D1? L00? You say all this is new,
but something is wrong.

Jon