Does anyone use coolant on their machine?
Originally shared by Tyler Harney
Currently making the plunge to converting the CNC to work with coolant. I’ve been toying around the idea for like a year now.
I haven’t figured it all out yet… Especially when it spews in all directions once it hits the endmill.
I have been involved in adding a coolant system to a DIY cnc mill.
If you do not have a full featured mill with coolant collection tray, you need to mist the coolant to reduce the amount of wetting on the milling table.
The basic idea is to make a mist through a misting head using air pressure and a small amount of coolant, ex. WD40.
You should buy an item like this:
And then add limited air pressure on the air hose and WD40 on the thin tubing. Both should have manual valve adjustment possibility. The WD40 entry should be able to be adjusted by a quality needle valve where you can adjust in very fine details.
You may need to add WD40 under small pressure too to make it flow stable. This is done with a special pressurized fluid container that has input for air pressure.
Since you need to adjust both air and wd40 in very fine detail, you should add magnetic valves on both pressure lines to be able to switch both off and on at the same time. That way you dont need to fine adjust every time your job require coolant.
All of this I havn’t done on my own CNC, because until now, I mill alu fine without coolant. I use a carbide single flute 4mm endmill at the optimal feed and speed for alu. My CNC is mechanical stable and this prevents chatter and therefore causes less friction heat.
Good luck 
Look at http://www.fogbuster.com/. There are also lots of posts by people who DIY’d the same idea. I don’t know that I’d use WD40. I think a gallon of coolant designed for this is a about $20, and you dilute that 10x before using so it will last a long time and does not smell like WD40.
I agree that WD40 smell and is a mess.
Yep, on the DIY machines and the commercial ones. Happy to help, what you want to know.
This is my approach to cooling: https://www.youtube.com/watch?v=09vAqSJP6zs&spfreload=10 
Mist coolant is my next addition, after a computer-controlled spindle.
