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Coolant Through Lathe Tooling Pressure

@Ox I think he's asking how many psi his through turret coolant pressure needs to be in order for a through coolant turning tool to be worth the extra expense.
 
I heard 1000psi with through tool can make a big difference in high temp alloys, but I never got to try it myself. I only have 145psi.
Thing is, many coolants will just foam at these pressures.
I have a through tool parting holder/blade but I never even used it yet, shouldn't have bought it in the first place. 300psi+ would probably be better for that anyhow.
 
Thanks guys, that is exactly what I was looking for. I am only running flood and wash down pumps right now. Currently I route boring bars and indexable drills if they have coolant passages. Even with the low pressure it seams to help.

I am happy to hear some are reporting gains with moderate pressure and not full 1000psi+ systems only. I don’t have a desire to go to a setup like that right now but was considering a booster pump.

For clarity, I was referring to all the external through coolant holders, such as parting blades, external threading, and general turning.

Thanks,
Mike
 
High pressure coolant is almost always desirable. In regards to if it is worth the hassle...that depends on if improved tool life is the goal. If better tool life is needed, then high pressure coolant is the way to go.
 
High pressure coolant is almost always desirable. In regards to if it is worth the hassle...that depends on if improved tool life is the goal. If better tool life is needed, then high pressure coolant is the way to go.
Blaser. Can you elaborate?

I’ll be picking up a lathe with 300psi within the month and will be tooling up
Through stick coolant is interesting but without metrics (guesses even) it’s hard to know if a small shop should pick up fancy holders
 
145 PSI through coolant is fine for indexable drills and boring bars and should be used if you can. More is better but 145 helps to get the coolant to the shielded cutting edge.

For stick tools 145 may be enough to help if the coolant ports in the tool aren't too small. The tool manufacturer may have minimum PSI requirements.

Through tool coolant may be better than fish eye nozzles, even at 145 psi. Fish eye nozzles are pretty crummy in terms of coolant aiming. We made some with a 3/16 compression fitting on the end to allow cheap custom nozzles using 3/16 copper tubing. Fish eyes also are notorious for creating fan-shaped coolant streams and the tubing nozzles help with that.
 
At what pressure do through coolant external lathe tool holders start to be worth the hassle? Or are they not worth the hassle?
Most MTB's rate their coolant passages for pressures up to 1,000 psi.
The internal coolant ports on most CNC lathes are, from the factory, a compromise.
Many folk buy the bronze nozzles from MSC that can better direct the flow and direction of coolant than the factory ones can.
Most CNC lathes have internal "thru the tool" coolant abilities and the ones that don't, there are plumbing sources to facilitate it.

For years, most lathes had factory pumps that were bare minimum. This, thankfully, has changed.
 
I like through tool / through spindle coolant every time i can get it. It prevents people from incorrectly aiming their coolant (yes, it happens) and it prevents chips/stringy chips from redirecting your coolant .....and....unintended benefit....no more chasing down loc line / fish eyes etc.
I am not sure about the ROI....but definitely makes the job easier.
 
I'm not sure what pressure my lathe has (standard HAAS coolant pump) but I use it for boring and drilling where I can - it makes a huge difference. I ran a 200 mm long 8mm drill through a stainless part a while ago and it was a breeze although the chips did start to block the flutes near full depth. U drills and the like it's very rarely an issue. Boring bars I struggle to get the coolant in the bore when the holder is close to the workpiece so through coolant solves this problem. Plus it flushes chips out the bore whereas blasting from the outside of the part seems to push them back into the bore.

I also use it for parting / grooving. I've used Tunagloy and ZCC grooving holders with through coolant. I prefer the Tungaloy holder (has a better positioned coolant port) but the ZCC inserts are more economical in cut just as well in my opinion.

For general OD turning and threading I use these which allow me to direct the coolant perfectly at the cutting edge so I don't see how through coolant would help here.
 
What I have found it is great for drills but for stick tools I did not get better tool life, I got more consistent tool life.
 
Blaser. Can you elaborate?

I’ll be picking up a lathe with 300psi within the month and will be tooling up
Through stick coolant is interesting but without metrics (guesses even) it’s hard to know if a small shop should pick up fancy holders

I have some through tool coolant holders, I find it helps even with a 300psi pump. I also use a bunch of nozzles from these guys www.qpmproducts.com I like the copper tube ones as well, nice to be able to bend and adjust them exactly where I want them to be. They have added a bunch of new stuff since I last bought from them. May need to order some new stuff :crazy:

Nice thing for us, is they are in Vernon BC. I bought a bunch and haven't needed to replace any, but at that time it was quick shipping and easy to deal with.
 
We picked up a new machine an op'd to add a high pressure coolant pump to help us break up stringy chips in 6061. Since we kept our old machines tooling we don't have any high pressure coolant through holders aside from typical boring bar and drills. I have been doing some experimenting with the brass lollipop nozzles and such to create a more focused spray which has marginally improved results.
I have a tool rep coming by tomorrow to bring some new inserts to test but wondering if we will need to invest not just in new inserts and/or coolant through holders, but even tooling blocks or bushings for boring bars to capitalize on the HP option. I can see coolant weeping from every conceivable hole in the tool assembly when I turn on the HP pump...
Any real world experience with this?
I'm sure every brand will say you need to invest in their proprietary system to get the best results, but how far do you go before you start seeing diminishing returns.
 
My experience was with capto tool blocks and all capto tooling so it was designed to handle all that. For standard tooling blocks hooking up to coolant through tool holders I would think you would be fine with standard plumbing that can handle the rated pressure between the two as long as you have good connection points. Is there a threaded connection under the ports for the brass nozzles that you could tie into? A little weeping won't hurt anything.

Some other major factors to consider with the high pressure coolant systems is heat generated and filtering. If you switch over a significant amount of your tools to HP or have a some that run for long cycles you will be generating a lot more heat than you might be used to. This can drive you insane with thermal growth if your machine doesn't have the capacity to manage the temperature or you might have to run some lengthy warm up routines to get the machine to stable and higher temperature.

Additionally if you aren't already setup with good filtration on your coolant up stream of these new through coolant tools you may clog them very quickly and it's a pain or impossible to clean certain tools holders out.

If your machine has the RPM or you aren't doing small diameters I would highly recommend PCD tools for anyone turning aluminum. SFM is essentially limitless and the increased speed can help break the chips. It can make the filtering problem worse though once you start breaking tiny chips that can run back through the system. Tools life is probably near infinite in 6061. My experience was with A380 cast and our tool life typically measured in weeks of cuttings time if they didn't hit an inclusion. The surface finishes are also incredible.

Walter makes good value D style profiling inserts. GWS bought out STF who was our main supplier for custom PCD inserts. Mainly groovers. They were pretty good, but the lead times were long on custom tools. VR Wesson was another we were testing with good results right as I left that shop.
 








 
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