Been working interstate but came home for the weekend so got a little done in the shed.
The mist cooling system that was fitted to the mill was junk. It created a cloud of coolant and you couldn't stand too close to the machine without breathing it in. Not pleasant or good for the health.
It was also a devil of a thing to get going. To get the coolant flowing you needed to turn the air pressure right up to get it started and then back it off once it was running. It used the vacuum created by the venturi to draw the coolant out of the reservoir. A pain if you wanted to turn the coolant off between tool changes as. If the bottle was too low it wouldn't draw. If I set the reservoir up high the coolant would siphon out of the bottle after shutting the thing off.
I spent more time fiddling with it trying to get it to work than actually machining. It also used way more coolant than you needed and that left the mill table / vice in a sticky oily mess once the water evaporated out of it.
I bought a Fog buster coolant system to replace it and it arrived the other day. This one uses a pressurized reservoir of coolant that's delivered to the nozzle along with the air supply. There is a needle valve in the nozzle to meter the flow of coolant and the nozzle precisely directs a jet of air and coolant droplets exactly where you want it. A regulator on the reservoir adjust both air and coolant pressure (both arrive at the nozzle at the same pressure). There is a check valve in the coolant line to stop it siphoning out or draining back to the reservoir and an air switch on the side of the mill to turn it on and off. Coolant restarts after tool changes are very quick to get going again. Really happy with how it works so far.
Here's the new nozzle installed.
Here's the coolant reservoir on the wall behind the mill.
I also rearranged some of the air plumbing. The regulator/oiler for the air draw bar was on the side of the mill but I figured it'd be tidier on the wall. Manifolding the two regulators together on the wall also cleaned up a lot of the airlines. I can now more easily get to the spindle brake and on/off switch.
Here's a link to the fog buster system if anyone is interested:
http://www.fogbuster.com/
Cheers