High-pressure holemaking

Author Alan Richter
Published
January 10,2017 - 04:15am

END USER: Modern Machining Technology Inc., (303) 945-7570, www.destroked.com.
SOLUTION PROVIDER: Industrial Coolant Systems LLC, (303) 968-1707, www.industrialcoolantsystems.com.
CHALLENGE: Reduce the cycle time when drilling a large quantity of holes in a 1018 steel part.
SOLUTION: A high-pressure coolant system.


Modern Machining Technology Inc. found that holemaking with standard cobalt drills and flood coolant could achieve the required tolerances when machining two holes in 1018 steel hubs, but the job shop wasn’t able to complete the needed 4,000 holes each month with that arrangement. Each 4"-dia. (101.6mm) hub has a 3⁄8"-dia. (9.525mm) hole on one side and a 3⁄32"-dia. (2.381mm) hole on the other side, and both are about 2¼" (57.15mm) deep. 

Scott Countryman, owner of the Wheat Ridge, Colo., shop, explained that each hole took about 40 seconds to produce with a feed rate of 25 ipm (635 mm/min.) and 0.007" (0.178mm) pecks on a DMG Mori DuraVertical 5100 vertical machining center.

Countryman said he knew Camoren Schley, president of Industrial Coolant Systems LLC, Denver, had developed high-pressure coolant systems because of the shop owner’s long-term relationship with Camoren’s father, Roger.



The VariFlow high-pressure coolant system delivers 10 gpm of coolant at up to 1,000 psi.
Image courtesy of Industrial Coolant Systems 


“Cam is a smart, young (23-year-old), ambitious guy,” Countryman said. “I wanted to give him the opportunity since finding a young guy that ambitious is very rare these days.” He added that units from ICS are about 80 percent of the cost of comparable systems.

According to ICS, high-pressure coolant systems for machine tools enable higher machining parameters than when applying flood coolant, thereby decreasing cycle times while extending cutting tool life and enhancing chip control.

After Countryman contacted Schley last spring, ICS installed its VariFlow high-pressure coolant system, which delivers 10 gpm of coolant at up to 1,000 psi (69 bar), provides 10µm filtration via a bag filter and has a built-in feeder pump. The latter means an auxiliary pump or strainer is not needed. In addition, the system’s adaptive flow control has a digital human/machine interface, which allows the user to input a set pressure; the VariFlow then dynamically adjusts the speed of the pump so output is at the desired pressure. Essentially, coolant flow is controlled regardless of the orifice size of the tool being applied.

The compact system measures 24" wide × 31" deep × 38" high (609mm × 787mm × 956mm).

With the high-pressure system in place, Modern Machining Technology needed to switch to through-coolant tools and selected carbide Dream Drills from YG-1 Tool Co., Vernon Hills, Ill. While applying the same water-based coolant, the shop achieves a tool life of about 500 holes with the 3⁄8" drill and about 600 holes with the 3⁄32" drill, Countryman said. Tool life is determined by monitoring the load meter on the machine tool. 

“When we see the load creep up,” he said, “we know the drill is getting a little dull and change it at that point.”

With the high-pressure coolant system, the shop runs the drills at a spindle speed of 10,000 rpm and a feed of about 116 ipm (2,946.4mm/min.) without pecking, producing a hole in about 1 second, Countryman said. On average, the shop operates about 12 hours a day, 6 days a week, he noted, and needs high-pressure coolant to deliver the required quantity of parts. “It just would not have happened the old way.”

In addition to job shop work, which represents the majority of Modern Machining Technology’s business, the company manufacturers the Destroked product line. These are the conversion parts needed to “destroke” truck engines, such as those from Ford, Cummins and Allison.

Related Glossary Terms

  • coolant

    coolant

    Fluid that reduces temperature buildup at the tool/workpiece interface during machining. Normally takes the form of a liquid such as soluble or chemical mixtures (semisynthetic, synthetic) but can be pressurized air or other gas. Because of water’s ability to absorb great quantities of heat, it is widely used as a coolant and vehicle for various cutting compounds, with the water-to-compound ratio varying with the machining task. See cutting fluid; semisynthetic cutting fluid; soluble-oil cutting fluid; synthetic cutting fluid.

  • feed

    feed

    Rate of change of position of the tool as a whole, relative to the workpiece while cutting.

  • inches per minute ( ipm)

    inches per minute ( ipm)

    Value that refers to how far the workpiece or cutter advances linearly in 1 minute, defined as: ipm = ipt 5 number of effective teeth 5 rpm. Also known as the table feed or machine feed.

  • machining center

    machining center

    CNC machine tool capable of drilling, reaming, tapping, milling and boring. Normally comes with an automatic toolchanger. See automatic toolchanger.

Author

Editor-at-large

Alan holds a bachelor’s degree in journalism from Southern Illinois University Carbondale. Including his 20 years at CTE, Alan has more than 30 years of trade journalism experience.