Dialing up precision holemaking

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END USER: 1-866-Dial-EDM, (866) DIAL-EDM, 1866dialedm.com. CHALLENGE: Produce a high volume of 0.006"-dia., 1/16"-deep blind-holes in an exotic material. SOLUTION: An EDM drill. SOLUTION PROVIDERS: Britton Machinery Sales Inc., (585) 241-3267; GF AgieCharmilles, (800) 282-1336, www.us.gfac.com

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The combination of precise, dependable EDMs and the ability to produce tooling solutions, when needed, has enabled a small shop to develop and maintain a thriving niche business. After founding EDM Express in 1997, company President William Utter later adopted the name 1-866-Dial-EDM, Orchard Park, N.Y. 

The shop provides prototype to production-level EDM services, primarily using wire machines, and has developed special expertise in EDMing small features and parts, according to Utter. He has considered expanding the three-person shop, but feels the current arrangement benefits his customers. “When someone talks to me about a job, I’m the one who is going to machine it,” Utter said. “People know that information isn’t going to get lost.” 

William Utter, president of 1-866-Dial-EDM, examines the setup in the AgieCharmilles Drill 11 EDM for producing a 0.006 "-dia., 1/16 "-deep blind-hole with a ±0.001 " tolerance. Inset: The Drill 11 creates the 0.006 "-dia. hole with a 0.0045 "-dia. tungsten-carbide rod. 

In its early years, the shop’s capabilities were “run-of-the-mill-type stuff,” Utter noted, with differentiation coming in the areas of service, reliability and turnaround time. As the trend toward smaller features emerged, the shop moved into small-hole drilling. To this end, it added a Drill 11 EDM drill from GF AgieCharmilles, Lincolnshire, Ill.

Having a hole popper enabled Dial EDM to target different jobs, including high-volume ones. Utter said: “We were doing some production runs on that machine and somebody came around looking for some really small holes and asked us what we thought. We said we’d like to take a good look at it. I haven’t met too many people who even want to try it.”

That’s because the job required EDM-ing a 0.006 "-dia., 1⁄16 "-deep blind-hole with a ±0.001 " tolerance in an “exotic” workpiece. Each part requires one hole, which takes 4 to 5 minutes to produce, and no other features. To explore whether the Drill 11 could achieve this 10.4 diameters-deep hole, Utter contacted Gordon Britton Jr. of Britton Machinery Sales Inc., Pittsford, N.Y., the local AgieCharmilles dealer. “We provided a part print,” Utter said. “Soon, we received sample parts back that had holes that were actually too small. At that point, I knew the parts were doable.”

As process development continued, Utter realized the high cost of the 0.0045 "-dia. tungsten-carbide tube electrodes used for test burns would make the job too expensive to move into production. The tube design allows through-electrode coolant flushing to increase cutting speed and the DOC. “To our knowledge, there is only one place in Germany making electrodes this small, and the prices are just through the roof,” he said.

Through research, Utter found a 0.0045 "-dia. tungsten-carbide rod electrode that might work and discussed it with Ken Baeszler, AgieCharmilles product manager, and Andrea Buzzini, the builder’s application engineer. Test burns revealed the rods could produce the holes at 10 percent of cost of the tube electrode. “If we had to go 1/8 " deep, it might have been a problem,” Utter said.

After a few more trial cuts, the shop was machining the 0.006 " hole within tolerance. However, electrodes were stuck in the collets, ruining two collets in a short period of time. “When you’re talking about getting a new collet for $800 with a 2- to 3-week lead time, it just didn’t quite fit into the equation,” Utter said.

After discussing the situation with Buzzini, the shop implemented a design suggestion to make the collet on one of its wire EDMs. It makes electrode loading easier, Utter noted, and eliminates the electrode getting stuck.

To date, Dial EDM has produced more than 13,000 parts without any problems and looks forward to machining thousands more. “It’s the single largest job we ever did,” Utter said. CTE