Clearing The Fog About 
Coolant Delivery Systems

Environmentally conscious machining is more than a buzz word to this machine toolmaker when it comes to understanding the most efficient coolant options for the small machine shop owner.

Southwestern Industries, Inc. (Rancho Dominguez, CA) has been manufacturing productivity equipment since 1963. The company revolutionized toolroom milling when it introduced the ProtoTRAKr CNC (computer numerical control) in 1985. Designed for the machinist on the shop floor, the ProtoTRAK eliminates the extensive setups usually required for production oriented CNCs. They also design and manufacture other equipment, including bed mills, knee mills, lathes, and machine tool measuring equipment.

In addition to making a line of machine tools, Southwestern uses them in their own manufacturing operations. Consequently, when the company decided to switch to a new coolant delivery system, they had a good reason for making the change. According to Mike Zolinschi, chief mechanical engineer for Southwestern, they had a problem in the shop with fogging caused by conventional coolant misting systems.

"Most fogging problems are caused by coolants that are atomized within the nozzle or nozzle tip," Zolinschi explains. "We knew that if our own machinists complained of fogging problems, our customers were probably equally dissatisfied. There was an additional problem with the system we were using, and that was the amount of coolant being used.

"There is a widespread discussion about coolant delivery systems among those in the machine tool industry," Zolinschi continues. "While dry machining would be the ideal, development of tools that mill, turn, and drill in the dry state presents a formidable challenge. To the small machine shop owner, this is a very expensive alternative. Delivery of coolant through the spindle also is very expensive. Special spindles are required and high pressures are needed to deliver the coolant.

"Many regular coolant systems either use large amounts of coolant," he notes, "or spray the coolant in such a fine mist that coolant clouds can, and often do, develop in the shop. So, our challenge was to find a system that could deliver the coolant at low pressures without excessive misting. The solution to our problem was a relatively new system, the Fog Busterr from Hench Manufacturing (San Clemente, CA). This system met our objective of minimizing the use of coolant while minimizing or eliminating the misting problem."

Customers Benefit From Their Experience

The Fog Buster is a low-pressure system that delivers coolant fluids to parts and tools without fine atomization. This effectively eliminates the fog of unwanted coolant that is carried into the surrounding air of the machine shop. It is ideal for milling, drilling, lathe operations, and many other machine tool applications.

The key to the patented Fog Buster is its design, which allows the coolant to enter the airstream inside the sprayer head. Coolant then flows as a continuous stream drawn by a strong airflow through the nozzle tube. The important difference between the Fog Buster and other systems is that coolant is not atomized at the nozzle tip. A small stream of coolant is carried with the airstream as it flows to the workpiece. In essence, the liquid spray is surrounded by the airflow, rather than mixed with it and turned into a fine mist or fog. This enables the sprayer to produce a small, accurate spray pattern several inches or more from its target.

The Fog Buster uses a precision needle valve at the sprayer head to adjust the coolant flow. The system operates on low air pressure (10 - 20 psi) and is able to deliver most types of coolant. Using the system increases tool life and improves material finishes by directing coolant accurately to the workpiece. In addition, the strong airstream cools, clears chips, keeps the workpiece clean for fast, easy handling, and makes possible cutting at high speeds.

"Most people are proponents of the 'do-as-I-say, not-as-I-do' syndrome," Zolinschi observes. "However, we at Southwestern Industries use what we sell. As a result, we are well-experienced, and when we find something that is very successful in our own machine shop, we know that it will be successful in our customer's shop. Workers accept the Fog Buster: we have replaced all of our coolant misters with Fog Busters and also have found that our customers are pleased with the system [as well]. What it amounts to is that people breathe easier and save on coolant, while meeting their machining requirements; i.e., the system accurately places the coolant where it is needed."

The system comes with either a «-gallon or 1-gallon plastic container coolant reservoir. A clear coolant bowl on the smaller model provides quick visual inspection of the coolant level. The 1-gallon model that Southwestern uses is provided with a sight gage. Because the system greatly reduces coolant usage, the time needed for coolant replacement is kept to a minimum. The system attaches to a variety of machining equipment quickly and easily, and is started and stopped by commands from the machine tool's control.

"Because of the success we have had using the Fog Buster," Zolinschi concludes, "we added it to the machine tools we manufacture. Due to its reasonable price, it was a natural to be part of our machine tools." Hench Manufacturing, Inc.