07-16-2009, 11:10 AM
The needle valve on the head of the Hench Fog Buster is reportedly a Combining Valve for adjusting the relative volume of air and coolant, and not to change the respective air /coolant pressures.
What is a combining valve and how does it work?
07-16-2009, 11:38 AM
Oh geez, this is a long discussion. I posted a long article about the Hench Fogbuster patent and how the needle valve works on PracticalMachinist. A guy named Karl posted a build article and a DXF file on rec.metalworking -- it's easy to find.
The Cliff Notes version is that it's just a single needle valve that's used as a mixer between the air line and the pressurized coolant. What's ultra critical about the FogBuster design is the diameter of the the spray tube, and the nozzle. If you don't follow those dimensions exactly, you'll get coolant fog/mist.
I made one, and it works great, by the way...