On Sunday, November 25, 2018 at 2:16:30 PM UTC-5, Bob La Londe wrote:
wrote in message
...

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.

--
Ed Huntress