EDM is an engineering term that refers to electrical discharge machining. Wire EDM or EDM is a metalworking process with the help of which a material is separated from a conductive workpiece by electrical erosion. In this process, the wire never comes into contact with the conductive work piece. The wire electrode leaves a path in the workpiece that is slightly larger than the wire. Most of the time a 0.010′ wire is used, which creates a gap of 0.013′ to 0.014′. The wire electrode, once passed through the workpiece, cannot be reused.
Wire electrical discharge machining is a complicated assembly, but efforts have been made to build this system in house. When building a wire electrical discharge machining system at home, the biggest problem is breaking the wire. Engineers often use the full 70 volt power, which the cable cannot handle. If a VARIAC is used, it can vary the AC output, producing variable voltages. You can also control and vary the DC output. If the voltage is maintained at 55 volts, a spark is produced without breaking the wire electrodes.
In the homemade wire electric discharge machining system, the reducer gear also works as an encoder and drills 50 equal-spaced holes. Primarily a ½ – 20 threaded rod acts as a feed screw. The counts go to a PLC, which is equipped with start, reverse and stop functions. It is equipped with a suitable motor, which allows easy rectangular movement. The home-made wire electrical discharge machining system is also complemented by manual switches for free burning.
Homemade systems can only be used to work on small workpieces. However, the developments have been encouraging and ensure an ongoing process that will definitely create a market for home built systems.