Sinker EDM Machines

How to choose a sinker EDM machine

A sinker machine transfers the shape of the electrode into the part: the electrode descends, the discharge removes metal, and a cavity mirroring the electrode is left in the blank. This is how moulds, blind slots, ribs and sharp internal corners are made — corners a cutter cannot produce, because it always has a radius.

So the choice starts not with the machine but with the electrode: its shape, material and weight have to be known in advance. In the catalog the permissible electrode weight runs from 20 to 500 kg, and that figure limits the work as often as the axis travels do.

Then three sizes are checked: the X/Y travels (from 300×200 mm on the CHMER D322CL to 3000×750 mm on the CHMER CM3076C), the table size — from 500×300 to 1000×600 mm — and the tank, because the part works submerged in dielectric. Workpiece weight in the catalog reaches 16,000 kg.

If the contour goes all the way through, a sinker machine is not the tool — it is faster and more accurate to cut it on a wire machine. The full line-up is in the EDM section.