Coolant bucket brigade be gone

Using buckets, barrels and hoses to manually replenish coolant in machine tools doesn’t cut it in this tight labor market or when a parts manufacturer wants to perform lights-out machining. That was the case for Precision Tool Technologies Inc., said Jim Goerges, president of the Brainerd, Minnesota, company.

“Like most companies, we were part of that 5-gal. (19-liter) bucket brigade,” he said. “It was always a pain in the butt.”

Goerges started PTT in 1993 with four products and now has about 6,000. The company does some job shop work but focuses primarily on the prescription eyewear industry.

“We don’t make lenses or frames,” he said. “We help the wholesale optical laboratories edge the lens to insert the lens into the frame and to put the prescription into the eyeglass lenses.”

The FullShop automated coolant delivery system monitors coolant usage at a machine tool sump and automatically replenishes coolant before it runs low. Image courtesy of Precision Tool Technologies

That manual approach, Goerges said, meant that coolant wasn’t replenished on a timely basis. Or workers would forget to do it, and a machine would run out of coolant, smoke, break tools and potentially crash. He also reasoned that his qualified labor was distracted from more important tasks when tending to coolant replenishment.

An additional problem was overfilling a machine with coolant.

“That happened all the time,” Goerges said, “where you bring coolant to the machine, you forget how much was in there or the sight glass wasn’t working because there was too much sediment in the tanks, and — lo and behold — you flood the machine.”

When the company decided to acquire machines that could produce parts in one setup or two at the most, automation was required for unattended machining because PTT didn’t want to add workers for the second and third shifts, he said. He calls unattended production “168 manufacturing” due to 168 equaling seven days a week times 24 hours a day.

Goerges tried with no luck to purchase a shopwide system that automatically would deliver mixed coolant with unique top-off concentrations. It seemed that there was no commercially available option, so he built one. The system needed to monitor all the machine sumps and accurately provide customized coolant percentages and de-foamers to machines.

“I didn’t appreciate at the time how difficult it really was,” he said. “How do you create this thing so it is predictable, accurate and repeatable?”

Goerges began by bringing a hose with a pressurized spigot to a machine.

“The machinist just needs to turn it on and turn it off,” he said. “It sounds simple — problem fixed. But the machinists are multitasking, get interrupted and flood the floor. That didn’t work.”