If you recall, I changed over my lathe chuck and obtained a great
improvement in lathe accuracy and finish quality. In both cases, I
made a shallow cut at a the slowest automatic feed settings.

Today I discovered something else: that if I do the same thing -- make
a shallow cut at the lowest feed setting -- but using coolant, the
finish improved beyond my wildest expectations, in fact, the turned
rod looks as if it was polished, with no visible imperfections.

Also, quite likely related, the chip made when using coolant, would
not break all the time, and instead it produced super long spiral
continuous chips.

I saved all three samples just for reference purposes.
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"Ignoramus14219" wrote in message
...
If you recall, I changed over my lathe chuck and obtained a great
improvement in lathe accuracy and finish quality. In both cases, I
made a shallow cut at a the slowest automatic feed settings.

Today I discovered something else: that if I do the same thing -- make
a shallow cut at the lowest feed setting -- but using coolant, the
finish improved beyond my wildest expectations, in fact, the turned
rod looks as if it was polished, with no visible imperfections.

That's good. But it's the lubricant qualities of the fluid that's doing it,
not the coolant properties.


Also, quite likely related, the chip made when using coolant, would
not break all the time, and instead it produced super long spiral
continuous chips.

Not good. However, if your feed is shallow and light, that may be the best
you can do. You want those chips to break, not to spiral.

--
Ed Huntress

On 2009-01-17, Ed Huntress wrote:

"Ignoramus14219" wrote in message
...
If you recall, I changed over my lathe chuck and obtained a great
improvement in lathe accuracy and finish quality. In both cases, I
made a shallow cut at a the slowest automatic feed settings.

Today I discovered something else: that if I do the same thing -- make
a shallow cut at the lowest feed setting -- but using coolant, the
finish improved beyond my wildest expectations, in fact, the turned
rod looks as if it was polished, with no visible imperfections.

That's good. But it's the lubricant qualities of the fluid that's doing it,
not the coolant properties.

Absolutely.


Also, quite likely related, the chip made when using coolant, would
not break all the time, and instead it produced super long spiral
continuous chips.

Not good. However, if your feed is shallow and light, that may be the best
you can do. You want those chips to break, not to spiral.

I guess, it was so because the chips were so thin.

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Iggy,
Never forget one very simple truth. The number one problem in cutting
anything is chip clearance. A bad finish is often caused by dragging the cut
chips against the work. Coolant helps flush the chips clear of the back of
the tool. Contrary to common thinking a fine feed actually complicates this
function because the chips are very fine. Tool geometry and feed rates are
the key to good finishes. The best finishes are produced when the cutting
nose of the tool is between 1.5 and 2.0 times the feed rate in width. Ed
mentioned that the chip should be breaking not curling. I agree, but the
material often will not allow that. It can be encouraged by increasing the
feed rate, creating thicker and more brittle chips, but you must also
increase the size of the nose of the tool for the sake of finish. Some folks
create chip breaker forms on the top of the tool. I do not because it
drastically effects the available life of the tool. Good tools are expensive
and if managed well, can last many years. I consider chip breaker forms tool
abuse. There is a big difference if the tool was bought by your employer or
by you, think about it. Obviously, there is a practical range for this tool
nose thing. Eventually the heat generated and required stiffness in the
setup will exceed the capability of your equipment, so compromise is in
order and each machine is different, but the principle applies everywhere.
Another factor to always consider is surface speed. Sure you can reference
books and tables and get an approximate answer, but most folks have no idea
what is really happening at the tool and what they are trying to achieve.
Effectively when choosing a surface speed, we are selecting a cutting
temperature. Our goal is to create a material temperature directly at the
cut that equals the plastic state of that material being cut. In that state
the cutting edge of the tool will experience the lightest load and the least
abrasion for the longest possible tool edge life. Of course cooling and
lubrication affects the end speed of the ideal solution. Since all machines
and setups are different, the manageable maximum tool loads are also
different. In that light, compromise is made by cut depth, not cutting
speed. I hope this helps.
Steve

"Ignoramus14219" wrote in message
...
If you recall, I changed over my lathe chuck and obtained a great
improvement in lathe accuracy and finish quality. In both cases, I
made a shallow cut at a the slowest automatic feed settings.

Today I discovered something else: that if I do the same thing -- make
a shallow cut at the lowest feed setting -- but using coolant, the
finish improved beyond my wildest expectations, in fact, the turned
rod looks as if it was polished, with no visible imperfections.

Also, quite likely related, the chip made when using coolant, would
not break all the time, and instead it produced super long spiral
continuous chips.

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

"Steve Lusardi" fired this volley in
:

A bad finish is often caused by dragging the cut
chips against the work. Coolant helps flush the chips clear of the
back of the tool

The other major factor when machining gooey materials like 6061 is
material build-up on the tool edge, causing a new, inaccurately formed
"cutting edge" to form. A combination of cooling and lubrication helps
prevent that false edge.

LLoyd

On Sat, 17 Jan 2009 15:04:23 -0600, Ignoramus14219
wrote:

If you recall, I changed over my lathe chuck and obtained a great
improvement in lathe accuracy and finish quality. In both cases, I
made a shallow cut at a the slowest automatic feed settings.

Today I discovered something else: that if I do the same thing -- make
a shallow cut at the lowest feed setting -- but using coolant, the
finish improved beyond my wildest expectations, in fact, the turned
rod looks as if it was polished, with no visible imperfections.

Also, quite likely related, the chip made when using coolant, would
not break all the time, and instead it produced super long spiral
continuous chips.

I saved all three samples just for reference purposes.


Igy just reinvented the wheel.

Congratulations.

Now you need to use a surface finish gauge and try various coolants and
admixtures.

This should keep you entertained for many months

G

Gunner

Whenever a Liberal utters the term "Common Sense approach"....grab your
wallet, your ass, and your guns because the sombitch is about to do
something damned nasty to all three of them.