High pressure coolant for all tools ?

Panza · Jan 14, 2021

With 1000psi coolant: I'm wondering if you can run full pressure to all types of tools ? This is on a Mori NLX lathe.
Small through-coolant drills and OD tools seems ok to run with full pressure to me, but I am wondering about larger U-drill and boring bars: For a U-drill with 32mm/1-1/4 shank the force trying to push the tool out of the holder is 563kg/1240lbs.
I don't know if this is a problem ? Any other tools where 1000psi can be a problem ?

Milland · Jan 14, 2021

It's not really an issue in my limited experience. Consider the forces pushing a large drill back as it enters the workpiece, if it moved from the coolant pressure it would certainly move from the cutting loads.

Perhaps the biggest issue might be premature wear of the pump, and the extra cost of electricity from running it when the utility is marginal.

If you had a custom tool with a large internal volume perhaps there could be problems from running high pressure coolant, but that's quite an outlier.

gregormarwick · Jan 14, 2021

As long as there is somewhere for the coolant to go, it will never develop much pressure against the tool. It can be an issue if you turn through coolant on on a tool that has no through coolant passages, but the outcome is generally a different problem, like hydro-locking the tool release.

The only problem I've encountered with 1Kpsi coolant is if the tool has a pressed in nozzle - it's generally not there anymore when you check the tool afterwards.

The bigger practical issue with running 1Kpsi coolant all the time for every tool is heating up and possibly foaming the coolant.

GENERALDISARRAY · Jan 14, 2021

Yes, foam and tank starvation has been my experience.

I try to limit the on time of the pump to the minimum with careful placement of the M codes.

DouglasJRizzo · Jan 14, 2021

As far as machining goes, hi-pressure coolant is quite beneficial. Depending on your coolant and other factors, you could wind up with a foaming issue.

Much of it depends on the conditions of cut. Even larger indexable drills can benefit from this function.
With that said, generally I reserve it for specific applications, and use standard pressure for regular machining conditions.

You'll notice that the standard pumps on most modern machine tools are VASTLY larger and higher in pressure than even "hi-pressure" pumps of a few years ago. This has a very beneficial affect on machining. With the improvements in tooling and machinery, this is a quantum leap forward.

Panza · Jan 15, 2021

Thanks everyone ! That was very useful info.
To avoid too much heat and foaming I guess I should get another pump for transfer from the machine sump to the tank for the HP pump. That way I can keep the standard pump and use each pump as needed. I will probably need two check-valves or one-way valves too.

DouglasJRizzo · Jan 15, 2021

Excellent idea!

Gobo · Jan 15, 2021

We run 1000 psi coolant on several machines and have never had a problem . We do have coolant chillers which helps keep foaming to a minimum, the warmer the coolant, the more it will foam. We use low pressure when we can, high pressure when beneficial.

Panza · Jan 15, 2021

The pump I have is a Knoll KTS screw pump, which runs at a set rpm. When the pressure into the machine is regulated down to say 100psi the foaming in the machine will obviously be less. I guess the pump will produce less heat in the coolant and use less power too when the pressure is set at 100psi ? The regulator will just let most of the flow bypass back to the tank. When I think about it maybe it won't be that much difference in energy or heat between running a small pump or large pump ? Saving wear on the screw pump might be the only thing making the two-pump system better. That might be significant though: A new pump without motor was $3500 last year when I got a quote. Just thinking out loud here.

Gobo · Jan 15, 2021

Panza said:
The pump I have is a Knoll KTS screw pump, which runs at a set rpm. When the pressure into the machine is regulated down to say 100psi the foaming in the machine will obviously be less. I guess the pump will produce less heat in the coolant and use less power too when the pressure is set at 100psi ? The regulator will just let most of the flow bypass back to the tank. When I think about it maybe it won't be that much difference in energy or heat between running a small pump or large pump ? Saving wear on the screw pump might be the only thing making the two-pump system better. That might be significant though: A new pump without motor was $3500 last year when I got a quote. Just thinking out loud here.

I am afraid that with that setup, you will still warm the coolant significantly. As with hydraulics, when you get a pressure drop without doing any "work" much of the expended energy shows itself as heat.

mhajicek · Jan 15, 2021

Running 1000PSI TSC on a VMC, a couple years a go I started using it on every tool I can. Haven't noticed any problems yet, and it helps tool life significantly. As said above, if there's a path for the coolant it won't build up pressure behind the tool. That 1000PSI is for static or near-static pressure with tiny TSC drills.

Search

Largest Manufacturing Technology Community on the Web

Search

High pressure coolant for all tools ?

Panza

Stainless

Milland

Diamond

gregormarwick

Diamond

GENERALDISARRAY

Hot Rolled

DouglasJRizzo

Titanium

Panza

Stainless

DouglasJRizzo

Titanium

Gobo

Titanium

Panza

Stainless

Gobo

Titanium

mhajicek

Diamond

Similar threads