EDM Technology From A User's Perspective

EDM (electrical discharge machining) is rapidly gaining popularity as more applications fit the "EDM umbrella." With this in mind, I recently spoke to Tom Peltz, general manager of Advanced Precision, Inc. (Rockaway, New Jersey). Advanced Precision has made the commitment to EDM technology and is now one of the largest EDM job shops on the East Coast, offering wire and ram (diesinker) EDM services nationwide. Mr. Peltz provided a unique view of EDM from a user's perspective.

Explain how Advanced Precision got into the business of EDM. 

The company was started in the mid-1980s by two tool-and-die makers. They originally planned to operate a stamping business, but soon found a lack of expertise in local EDM services. They saw jobs being `no quoted' that they knew they could do themselves. They purchased their first EDM machine to do their own work, but once this was in place, they realized being an EDM job shop provided a better niche and more growth opportunity for their business.

What do you view as the main benefits of EDM? 

EDM allows all types of conductive materials, in all hardness levels, to be cut relatively easily. Complex shapes, tapers, conical sections, and pockets can be produced without affecting the integrity of the piece—and all this is done burr-free!

What types of jobs are best suited to EDM machining? 

Die work is probably most associated with EDM technology, because EDM came about to help the die makers with punches and dies. Now with all types of exotic materials being used, EDM has reached military, surgical and aerospace applications.

How do you decide whether to use a wire or ram machine in a specific application?

The jobs themselves will usually dictate which process is better. In general, parts with an open contour or inside shape are better suited to wire, while parts with a blind pocket or exterior feature are best produced on a ram machine. With a choice, it comes down to economics.

Have you seen a greater acceptance of EDM by customers and the metalworking community in general? 

We have seen increased acceptance of EDM, usually after you have gotten someone out of a bind by doing something they thought was impossible, or by offering an easier solution. We have many years of EDM experience and often, by just doing what we know, we can really help out a customer.

What does EDM offer that other technologies do not? 

I see the main benefits as burr-free machining, low heat penetration into the material (thus not affecting hardness), close tolerances, and excellent repeatability in production situations.

What do you see as some of the down sides of EDM technology?

EDM is black magic. The number of variables associated with wiring a piece is astounding. Fortunately for us, an EDM machine will never be the Bridgeport miller of the future, where every shop has one. There will always be a high level of competence needed to make the machines perform properly.

What do you see as the next great advances in EDM technology? 

I don't foresee any great advances in EDM, but I think the peripherals will be refined. Things like transformers, generators, water filters, and flushing apparatuses are becoming more efficient, reliable and compact. Right now, our newest machine is about half the size and cost of our oldest machine and has the same work capacity.

Are you evaluating alternate technologies to help grow the business? 

We are looking at laser cutting and waterjet cutting. We want to be a full service cutting shop and offer our customers the most economical solution to their cutting needs. These different technologies will allow us to achieve the quality and turnaround time that our customers need, while allowing us to be competitive.