Coolant Pumps

[thetrillionaire]

Another machinist and myself got into a discussion. When we run delrin in the mill the programmers still leave the M08 (coolant on) command in the program. We just turn the valve off at the spindle, does this cause wear on the coolant pump? Would it be better for it to shut the coolant off all together?

[fuzzyracing1967]

Well if your not using coolant why make the pump work for nothing? I would just take the M08 out of the program or better yet let the programers know it's not needed.

[PBMW]

Just out of idle curiosity, why don't you want coolant?
It really helps with evacuating chips.
Some plastics I run dry. In fact most of them. But there are times when I use coolant. Are there pockets? or is this just a little part with little real cutting going on?
I tend to get a little bent when someone goes in and starts editing my code. Forgive me as I don't know your experience....

[thetrillionaire]

Simple answer, it's easier! When the stuff gets wet it sticks to every suface in the machine and makes cleaning up more of a chore. The chips do a good enough job of clearing themselves out. Sometimes a well placed air blast is needed.

[HelicopterJohn]

I presently have a TM-1P and am thinking about installing HAAS's PCOOL coolant option on my machine.

Another thought I had was making a small bracket to attach to the PCOOL nozzle that would hold an air line in a parallel position. This line would be piped to the outside of the cabinet to a valve and you could manually give it an occasional air blast when desired. The air line could be run through a regulator to adjust the air flow to a suitable pressure.

John

Originally Posted by thetrillionaire Simple answer, it's easier! When the stuff gets wet it sticks to every suface in the machine and makes cleaning up more of a chore. The chips do a good enough job of clearing themselves out. Sometimes a well placed air blast is needed.

[Geof]

What are your typical speeds and feeds? We run some Delrin parts one inch thick with 7/8" ID through hole, and without flood coolant we would finish up stirring a pool of melted plastic in the vise.

[thetrillionaire]

we tend to do mostly ballmill profiling in the stuff. We also do some heavy pocketing and if your not paying attention and cleaning the endmill after each ramp you can end up with a lump of plastic where it used to be. But i've never seen such a cut come that it has actually melted the workpiece

[Geof]

I did exaggerate a little. We have sort of welded the chips to the part embedding the cutter and finished up with the parts turning in the vise jaws and lifting out when the tool retracted.

[Gary55Ford]

Hi All I use alot of delrin were I work from 1/16-2" thick I've never used coolant on it. I use 2 flute endmills at around 1400rpm at 10-20ipm I use a coolblast insterment cabinet cooler. It uses compressed air It somehow seperates the cold air from the hot, hot air comes out of the back and almost freezing air comes out of the front. It works great on all plastics, even PVC thats a pain in the --- to machine.

[Geof]

Originally Posted by Gary55Ford .... 2 flute endmills at around 1400rpm at 10-20ipm...

I guess my difference is 10,000rpm and 120 ipm with a 1/2" two flute interpolating a 7/8" hole through 1-1/4" thick Delrin in six circles; the cutter is engaged around 80% of the diameter and the helical ramp is about 0.2" per circle.

[Gary55Ford]

Geof All I have to work with are knee mills & a bed mill, they only have a top speed of about 4,300rpm so I can't do any high speed machining, wish our company had some high speed machining centers. But most of our machining is one off proto-type stuff and machine building.