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