Published 8/2/2011

A Novel EDM Application

GF AgieCharmilles designed the FO 550 SP die-sinking EDM, the company probably never imagined it would be used like this.

Machines
EDM

Matt Danford

Former Senior Editor, Modern Machine Shop

Have you ever seen anyone open a bottle with a cigarette lighter or pry open a container with a screwdriver? Similarly, perhaps you’ve seen children using garbage can lids as sleds on a snowy day or attaching playing cards in their bicycle spokes to make noise. Our everyday lives offer countless examples people using things in manners that are completely inconsistent with the intent of their original design. When engineers and machine tools are involved, things get a little more complicated, but the basic principle remains the same: Any given tool or device can likely be employed with striking effect in unexpected ways—ways that can sometimes lend a competitive edge.

The pictures on this page, taken at GF Machining Solutions LLCGF AgieCharmilles’ “Technology Days” event at the company’s Lincolnshire, Illinois headquarters in late June, depict one example of a machine tool being used in a new, innovative way. When the company designed this machine, the FO 550 SP die-sinking EDM, it likely never considered that it would ever plunge an electrode into a workpiece via any direction other than Z. However, thanks to the company’s creativity and a custom-designed fixture, one of its customers is now using the machine’s horizontal X axis to burn 16-inch-deep channels into cylindrical, aluminum parts like the one shown here (the outer portion of the sample part has been cut away for visibility).

The custom fixture is slightly smaller than the electrode to provide clearance in the narrow channel. A channel running through the middle of the fixture brings dielectric fluid directly to the point of burn.

That particular customer came to Agie for help with developing a production process when it realized there wasn’t enough room on its FO 550 SP machine to mount the part vertically on the table. The channel would be too small to mill or drill, and on top of that, maintaining a consistent surface finish throughout its depth was critical. For Agie, the most challenging part of developing this novel, horizontal approach was the fixture holding the electrode. This long component is constructed of various jigsaw-puzzle-like sections that were wire EDM’ed out of a solid block and press-fit together. While not visible here, a hole runs lengthwise down the center of the fixture and then splits 45 degrees in opposite directions to deliver dielectric directly to the point of the burn.

During a demo of this application for myself and other members of the press, I started wondering about other instances of shops employing equipment in unexpected ways. If you know of any examples and are willing to share, post a comment below or send me an email.