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On Sunday, November 25, 2018 at 7:25:54 PM UTC-5, Bob La Londe wrote:
On 11/25/2018 1:37 PM, wrote:
On Sunday, November 25, 2018 at 2:16:30 PM UTC-5, Bob La Londe wrote:
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On Sunday, November 25, 2018 at 11:01:21 AM UTC-5, Bob La Londe wrote:
Who uses flood coolant on their manual lathe?

Do you get sprayed when using it? Do you waste a lot of coolant.

I was turning some 304 stainless yesterday on the 1440 and
everything was
going fine until it started to get hot. Then it cooked inserts,
and fast.

If you run flood do you stop using insert tooling?

Until now I've just used a cutting oil on the lathe when the cut
seemed to
act like it needed it.

What kind of inserts did you "cook," Bob? It's AWFULLY hard to "cook"
a
carbide insert at normal cutting speeds. Were you using HSS inserts?


******** I have a heavy hobby machine. Its a PM1440. Weighs in at
about
2000lbs with a 3HP spindle motor. Interestingly I was able to machine
4140QT TGP at the same DOC and feeds with little issue with the same
inserts. I'm in the process of "hogging" off materials as fast as I
can so
I am pushing it as hard as I can.

As a side note. I had issues with another modestly difficult
material on
the mill this year. I was machining 4140HT and kept killing cutters.
I
went to an AlTiN coated mill and it got better, but tool life was
pretty
short. Short enough it was affecting the profitability of the job.
I tried
flood coolant against all common wisdom, and I was able to increase
tool
life. It did not shatter from thermal shock as so many said it
would. I
also tried some uncoated mills and they did die almost instantly.

When you get into coated cutters, especially like your AlTiN
(Alox-TiN?) multi-coated ones, things can get very weird. Assuming it
*is* Alox on top, the more sophisticated ones generally are made for
high-speed use (up to 3,000 sfm or more), and they have to run dry, or
their life is short. It's the vaporizing Alox that actually serves as
the lubricant.

Most multi-coated inserts are made for a specific application, or a
narrow range of applications. When you use them other than as intended,
it's hard to predict what will happen. That's not to say they won't work
well in other applications, but you have to work out the details for
yourself.

So anecdotal information about coolants is going to be a little iffy.
Good luck -- whatever works for you.


It was one of those things I tried in desperation. It seemed to work at
3600 RPM with a 1/2" 6 flute on the Hurco and 1/4" 4 flutes SE and 1/32
2 flute balls noses on the Speedmasters at 16000 to 24000 RPM.

I thought AlTiN was Aluminum Titanium Nitride. I know if I try to use
it on aluminum it chip welds pretty quickly.

Yes, I try things. Sometimes dumb things. I remember when I was trying
to learn about high speed milling aluminum and somebody said basically
what you said. Well in a more complimentary manner. They said, I might
just be THE expert in what I was trying to do. I took that to heart and
just started trying things.

Anyway sometimes dumb things work.

I don't know what I did differently today, but I was able to use
basically all the same tools (well I had to make a trepanning tool) and
finished all the roughing operations on two of the stainless parts I was
making. I didn't burn up a single insert. Except for increasing RPM on
smaller diameters a little more aggressively I didn't do anything
majorly different.

It keeps it all interesting. g I think I've been away from this for too
long. I see that "AlTiN" is the designation, and then a discussion of
"formed" AlOx follows, suggesting that the coating is aluminum, which then
oxidizes in use. That is NOT the way it was described when I was trying to
sort out manufacturers' claims for multi-coated inserts. The AlOx was
applied as a ceramic coating. They do say it's primarily for dry machining,
but...

Sheesh. Anyway, there is just one more tidbit of info that may be useful. If
you're having sticking problems, consider one of the multi-coated inserts
with a soft coating. There were several, including a moly disulfide coating
and something else that I don't remember. The purpose of the soft coating
was to help "break in" the hard coating underneath (TiC, TiN, or TiC-N,
usually), polishing off the rough spots, which left a much smoother surface,
less inclined to stick.

But this is getting to be old info, so maybe it's time to talk to an insert
manufacturer. They're usually good at helping with application info.

**** First off I put down the wrong RPM on the Hurco. I never milled
4140HT that fast with it. Brain Fart. I did run that fast with the
Speedmasters, but light high feed cuts. Or light low feed cuts with the
really small mills.

No on aluminum I don't have issues with sticking. For the most part I use
uncoated high helix mills and a double blast of flood coolant. I was just
commenting that when I tried the AlTiN coated they had issues.

Its funny. Everybody talked about ZrN coating for aluminum for a while, but
I never was able to justify it for the results I got. I found I got the
best material removal rate and the best finishes with uncoated fast helix
and a blast of flood coolant. Maybe tool life is better with ZrN, but I'm
afraid I tried them when I was still learning and few tools survived bad
feeds and speeds. LOL.