On 25/11/2018 19:16, 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?Â* 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.Â* 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?


********Â* I have a heavy hobby machine.Â* Its a PM1440.Â* Weighs in at
about 2000lbs with a 3HP spindle motor.Â* Interestingly I was able to
machine 4140QT TGP at the same DOC and feeds with little issue with
the same inserts.Â* 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.Â* I had issues with another modestly difficult material
on the mill this year.Â* I was machining 4140HT and kept killing
cutters.Â* I went to an AlTiN coated mill and it got better, but tool
life was pretty short.Â* Short enough it was affecting the
profitability of the job.Â* 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.Â* I also tried some uncoated
mills and they did die almost instantly.

One benefit of coolant is that it can help maintain the workpiece
temperature near constant so it doesn't expand. I use it sometimes for
that reason when machining thing like titanium and 310 stainless,
otherwise I rough it down to near final size and leave it to cool for an
hour of 2 before taking final cuts. Coolant can be messy sometimes if it
gets flung off the chuck but I have splash shields I can fit if it's a
real issue.