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EDM Electrode programs

Copper electrodes

Machining copper is fairly easy but there are some pitfalls to watch out for:

 Copper work-hardens, which means that the more you push the material about the harder it becomes. Therefore sharp cutters with the correct geometry are essential.

Failure to use sharp cutters will lead to poor surface finish, large burrs and incorrect finished sizes. We recommend the use of solid carbide cutters wherever possible. The extra initial cost is easily recouped by the extra life span achieved over HSS cutters.

 Most copper bar and plate has a 'skin' which is under tension, which means that when cut the electrode has a tendency to bend. How much distortion that occurs will depend on the size and shape of the copper blank and how much material is removed.  Care needs to be taken in the machining strategy employed and with the method of holding the electrode to overcome this problem.

Small ribs and features can easily bend and break off if the wrong machining strategy is used. We have developed methods of machining even the tiniest of features without problems.

Incorrect finishing strategies can leave dwell, and machining marks on the  surface of the copper that are difficult to polish out. Ideally you want the CNC machine to get the best finish possible to cut dressing and polishing down to a minimum.

Bad choice of cutter sizes and strategies when picking out corners can lead to cutters pulling-in to the work-piece and gouging. This can lead to extensive polishing, re-cutting the electrode or even having to scrap the electrode and start again.

Our huge experience in producing programs to machine copper electrodes means that  we can avoid all these pitfalls and you can be confident  of first class results every time.

Graphite electrodes

Graphite is more forgiving to machine than copper but there are still a couple of points to watch out for:

Graphite is abrasive so watch out for cutter wear. Excessively worn cutters can lead to chipped edges and poor surface finish. Carbide cutters are essential for all but the smallest amount of machining. If you are machining large quantities of graphite then diamond coated cutters may be a worthwhile investment.

Small features can be difficult to machine and prone to breaking off. Here at Alphatech, through many years of experience we have developed methods that will enable you to machine most small features without breaking.
Graphite does have some definite advantages over copper: as well as weight and cost, generally much longer cutters can be used successfully with graphite, especially with high speed machines also stress distortion is not a problem.

We know a great deal about machining graphite from years of experience - We can help you take advantage of the time saving benefits of rapid graphite electrode production.

page | by Dr. Radut