Todays Project - What did you do today?

[Hawkeye]

I decided to try to make a mist coolant gizmo, loosely based on some I've seen on the internet. The main push for this was getting a flood coolant nozzle with magnetic base through the local tool store.

Some that I've seen use two pressure regulators. One for the air flow at the nozzle, one to pressurize the liquid supply bottle. I decided to try using just one, mostly because I didn't buy a second one when it was on sale recently. Mine uses one regulator to adjust the air flow through the nozzle, with that pressure also entering the bottle to push the coolant out. The tube coming vertically out of the brass fitting carries the liquid to the nozzle.
   

Rather than mix air and coolant before they go down the flexible tube to the nozzle, I ran a thin nylon tube down the middle of the flex to carry coolant to the nozzle itself. I filed three notches around the opening of the original nozzle to allow good air flow out past the thin tube. There is also an insert made from 1/16" O.D. brass tubing in the end of the tube to restrict the flow.
   

I made up an aluminum block to allow mounting of the flex tube and connect the air and coolant lines. In my first attempt, I used the valve that came with the nozzle assembly. Leaked like a sieve. The screw on the top of the fitting is a needle valve I made from a bolt, to regulate the amount of coolant coming out.
   

Today, I picked up a small needle valve at the hardware store and reworked the regulator stage. Now there are no leaks and I can turn the coolant flow as low as I want.
   

I haven't tried machining with it yet. I'm going to work out a better method of hanging the supply bottle so the rig can be easily moved from machine to machine. Reports from other builders indicate that coolant usage is quite low. I'm using a semi-synthetic water-soluble oil for my first trials.