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DIY high pressure coolant

Cole2534

Diamond
Joined
Sep 10, 2010
Location
Oklahoma City, OK
From time to time I drill a lot of deeper holes, 3/4" diameter and 8x deep. This sucks with flood coolant and traditional twist drills so I want to cobble together some sort of HP coolant arrangement to allow me to run coolant through spade drills.

This obviously would not be a manual tool change, and probably in the lathe so the drill is not spinning.

How much pressure and flow does a guy need? Are there reasonably priced pumps that will move, say, 250psi coolant? I'm halfway tempted to buy an electric pressure washer arrangement, arrange a relief valve and say send it.
 

GregSY

Diamond
Joined
Jan 1, 2005
Location
Houston
I don't have much experience in this but I wonder why you'd need much PSI at all. It seems the coolant is gonna find it's way down the drill and out the hole whether you force it hard or not.

We used to have twist drills with coolant holes...though I would guess 3/4" was about the smallest.
 

Garwood

Diamond
Joined
Oct 10, 2009
Location
Oregon
I don't have much experience in this but I wonder why you'd need much PSI at all. It seems the coolant is gonna find it's way down the drill and out the hole whether you force it hard or not.

We used to have twist drills with coolant holes...though I would guess 3/4" was about the smallest.

High pressure makes all the difference in the world. At higher pressure the chips are removed more effectively and more coolant flows where needed.
 

gbent

Diamond
Joined
Mar 14, 2005
Location
Kansas
If I was going to rig up another high pressure unit I'd feed it off the standard coolant pump. That way I could use a fine strainer to remove the swarf before it went to the high pressure pump. I've had 10 stage centrifugal, gear pumps, and plunger pumps. You just need the flow to wash out the chips, the pressure is just the result of the restrictions you have in the flow path. If you can get 4 gpm you won't have any problems.
 

eKretz

Diamond; Mod Squad
Joined
Mar 27, 2005
Location
Northwest Indiana, USA
High pressure makes all the difference in the world. At higher pressure the chips are removed more effectively and more coolant flows where needed.

Especially on deep holes. Higher pressure will push the chips out of there and keep things clear and free-cutting. It's not just about keeping things a little cooled off. If chips bind unevenly in the flutes it can cause the drill to cut a very crooked hole.
 

dian

Titanium
Joined
Feb 22, 2010
Location
ch
how much flow do you need?

you could get two 10 bar winshield washer pumps off ebay and run them in series for 300 psi. or get a water/methanol pump (200psi/1gpm) for about $200 (summit racing?)
 

BT Fabrication

Stainless
Joined
Nov 3, 2019
most high pressure pumps are just standard industrial pressure washer pumps fed from the main coolant pump and a really fine filter between it to keep the junk out.
 

SVFeingold

Aluminum
Joined
Aug 7, 2015
Location
Santa Clara
What do you consider reasonably priced? You should be able to do this for $1000 ~ $1500 I'd bet.

Flowrate/pressure ultimately depend on your plumbing and tooling. The only question for the pump is whether it can meet the demand or not. If not, nothing catastrophic will happen. You just won't be getting optimal performance.

As long as the pump is protected (e.g. fine filtration + relief/bypass + ensuring it isn't starved) and your plumbing is on point, there's nothing really crazy about it. Since it sounds like you won't be feeding pressurized coolant through a spindle your filtration requirements won't be quite as onerous - you only need to protect the pump. It wouldn't hurt to think about the seal between the OD of the drill and the tool holder, otherwise a lot of your coolant will find its way out of there. Which will reduce the pressure where it's needed (especially if your pump is barely adequately sized) not to mention will make a mess unless your lathe is fully enclosed.
 

Philabuster

Diamond
Joined
Jul 12, 2006
Location
Tempe, AZ
Lathe is a Mazak QT15n, so it is totally enclosed. Is there a pressure limit on the turret coolant seal?
If it was me, I would just replace your stock coolant pump with a multi-stage Grundfos coolant pump off ebay. You will need to adjust or change out the contactor in the machine to handle the extra amps to feed a larger HP pump.
 

Cole2534

Diamond
Joined
Sep 10, 2010
Location
Oklahoma City, OK
If it was me, I would just replace your stock coolant pump with a multi-stage Grundfos coolant pump off ebay. You will need to adjust or change out the contactor in the machine to handle the extra amps to feed a larger HP pump.
I happen to have one sitting unused. Would you reuse the deutsch connector/wiring from the factory?
 

Philabuster

Diamond
Joined
Jul 12, 2006
Location
Tempe, AZ
I happen to have one sitting unused. Would you reuse the deutsch connector/wiring from the factory?
Depends on the pump. Grundfos makes pumps in 100s of types. I wouldn't use it if it has near the same output as your factory pump. I am talking about getting one that has 200 psi output with a 2 or 3hp pump motor.
 

Cole2534

Diamond
Joined
Sep 10, 2010
Location
Oklahoma City, OK
Depends on the pump. Grundfos makes pumps in 100s of types. I wouldn't use it if it has near the same output as your factory pump. I am talking about getting one that has 200 psi output with a 2 or 3hp pump motor.
Ill check the data plates and compare specs, thanks.

You need any ideas for a new video? I need to turn a sphere on the end of the shaft. ::)))))
 

Philabuster

Diamond
Joined
Jul 12, 2006
Location
Tempe, AZ
Ill check the data plates and compare specs, thanks.

You need any ideas for a new video? I need to turn a sphere on the end of the shaft. ::)))))
Check out my video titled Demo Part 2. I am turning a trailer hitch ball part. Sounds like that is what you need to do?
 








 
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