DIY Electric Discharge Machining (EDM) Projects

Here is an index of my posts about pursuing DIY electrical discharge machining (EDM).

Introduction to EDM

Electrical discharge machining (EDM) is a fabrication technology that carves material off of a workpiece by producing many sparks between an electrode and the workpiece. Each spark produces a tiny crater in the surface of the workpiece (as well as the consumable electrode), and over time the sparks erode all the material within a certain distance of the electrode. A key advantage of EDM is that there are only miniscule cutting forces, which enable it to produce extremely accurate parts with tiny features and uniform surface finish, although it is a slow machining process, especially for better surface finishes. EDM can be used in a variety of ways to machine conductive materials, which all use the same electrical process:

EDM drilling uses a thin tube as an electrode produce very narrow holes with extreme aspect ratios (i.e. very deep compared to the width of the hole).
Die Sinker EDM uses a negative of the desired feature as an electrode to subtract it from a workpiece, leaving the desired feature.
Wire EDM uses a thin wire as an electrode to cut the workpiece like a wire foam cutter.
EDM milling uses the electrode like a milling cutter, but it can use sharp cornered electrodes to machine sharp internal corners that are impossible with a normal milling cutter.

EDM machines have specialized industrial tools that are outside the reach of hobbyists until very recently, when BaxEDM created an EDM pulse power supply aimed at lower cost machines. However, the BaxEDM power supply would put a DIY EDM machine outside my budget, so for a while I casually researched the process in the (optimistic) hopes that I could design my own power supply. The EDM process is speciallized enough that there is unfortunately very little information online. I eventually found a copy of a textbook that high level enough to be a good starting point.

DIY EDM Posts

EDM Power Supply