Actually, after the first trial, I was going to make three more, but as usual other things got in the way, and because it required no more development as it mixed perfectly at the nozzle, I never got around to making the others, but I do have everything ready to go sitting in a box.
I think why this proto system worked so well was because the air and oil were kept separate until the very last second, and not have an internal mixing chamber. So like being shown in one of the commercial units, the Fogbuster, the lube comes out as droplets rather than a mist.
I honestly think the secret was in keeping the fluid nozzle fairly large, and when correctly set, it was protruding just slightly from the tapered outer air nozzle.
I regularly used to part off 3″ material (even stainless) and just pointing the nozzle down the slot kept the piece being parted off cool enough to hold in your hand just after it fell off, so the air was keeping it well cool, and with not one drop of coolant being thrown at me.
BTW, just as a word of caution, set the air too high and the shop will start to mist up in minutes, giving you an almost instant cough. I run mine just enough to lift the liquid from the open to air tank, with the oil/water mix level just a little lower than the nozzle. 5 to 10 psi should be more than ample to lift the liquid from tank to nozzle.
Like most things, I am sure it could be made a lot easier to make, but I was well satisfied with what I ended up with, and costing a lot less than a tenner for everything required to make it, I can’t complain.
BTW, my Locline came from my usual supplier of cheapo stuff, Richon Tools.
John