Published 6/1/2012

How to Reduce EDM Setup from Hours to Minutes

The right software helps automate EDM setup and avoid EDM programming errors.

Hari Sridharan

Detailed, automated design of electrodes, from simple to most complex.

A combination of highly automated NC programming with full user control.

We all know that EDM setup can be extremely time-consuming. Automating the setup process can save valuable time, especially when considering that some tools (especially those with multiple cavities) require dozens or even hundreds of electrodes.

As significant as these time savings can be, the benefits of automating the EDM setup go beyond just speeding up the process. By the time you are ready to burn electrodes, the tool is almost done. Any mistake in the EDM process will put to waste the many hours already invested in the tool. Even more critical, it can jeopardize delivery time. Automating the EDM setup is the best way to avoid any errors in EDM programming and eliminate these risks.

Following are four items to consider when looking for EDM setup software:

1.   Integration with CAD and CMM data
Tight integration with CAD data is critical for the accuracy of electrode burn locations and depths, ensuring continuous data consistency from the core and cavity data to the electrode design and to the EDM sinker setup.

Integration with CMM data further guarantees accuracy. Your EDM setup software should be able to self-correct and compensate for any location discrepancies between the design and the actual manufactured tool based on the data received from your CMM software.

2.   Complete control over all setup parameters
The EDM setup software should provide an easy way to define and control all relevant EDM process data. General parameters displayed and handled through an EDM setup wizard should include electrode identification, material, electrode type (rough, re-rough, finish), orbiting type and size, spark gap, location, burn depth and any other parameters needed based on the specifics of the machine and process used.

In addition, it should give the EDM operator complete control over the burning order of the electrodes, as well as the ability to reverse the order for roughing, pre-finishing, finishing and polishing electrodes. It also should be able to address multisided electrodes, which are commonly used in the industry.

3.   Customized to your machine and your application
The ability to customize the EDM setup program for your machines is critical, as each machine has a unique set of parameters that must be specified.

But even the same type of machine is likely to be used differently at different tool shops. For example, in the automotive industry it is common to see one or two-cavity molds, while in electronics and household goods we see molds with as many as 64 cavities. Each of these machines would require a completely different method of EDM setup programming.

4.   A picture speaks a thousand words (or numbers)
Due to the high sensitivity of getting the electrode location right, EDM operators typically refer to drawings they can cross-reference with the numeric output they receive. Providing operators with access to view-only software instead of the traditional drawings not only saves time and trees, but also allows the operator to better visualize the tool and the electrode locations in 3D.

The bottom line is less time, fewer errors and greater confidence. Automating the tedious task of manually programming EDM sinkers can reduce programming time even for the most complex electrodes to 20 minutes or less. With the right EDM setup software, you can reduce your EDM setup time by as much as 95 percent, eliminate the need for extensive dry runs, and most importantly—never burn an electrode in the wrong place.

Zero EDM Setup?

While automating EDM setup can save significant time and dramatically reduce the risk of costly errors, an even better strategy would reduce or eliminate the need for EDM altogether. Many tool shops are implementing advanced machining strategies to do just that.

Marland Mold is one of these shops, as John Nykorchuk explains, “With our 5-axis machines, we are able to use smaller tools and tilt the part in such ways that we can machine all the corners and avoid the use of electrodes. As a result, a significant portion of the EDM work we used to do is no longer needed.

I can think of one part that used to require five different electrodes that we can now do without any EDM and with one single setup. This has eliminated the need to design the electrodes, program them, and do the burning with five different setups. The time savings could easily be as much as 25 percent of the overall production time for that mold.”