Day 1: The Science of the Spark
Before touching the controller, you must understand how metal is removed without physical contact.
The Spark Gap: Understanding the microscopic distance between the electrode and the workpiece where the plasma channel forms.
Dielectric Fluid: Learning how to manage the oil/fluid that acts as an insulator, a coolant, and a flushing agent.
Electrode Materials: Comparing Graphite (fast wear, high metal removal) vs. Copper (fine finishes, high detail).
Polarity: Why switching the "+" and "-" between the tool and the part changes the wear rate of your electrode.
Day 2: Machine Setup and "Burn" Parameters
Day two moves into the technical configuration of the CNC generator. Unlike a mill, an EDM doesn't just have "speed"; it has "On-Time" and "Off-Time."
Setting the Z-Zero: Touching off the electrode to the part surface (often done submerged in oil).
Generator Settings (V-P-A):
Voltage ($V$): The pressure behind the spark.
Peak Current ($A$): The intensity of each individual spark.
Pulse Duration: How long the spark lasts versus how long the machine "rests" to let chips flush out.
Orbiting Strategies: Learning how the machine moves the electrode in small circles or patterns to create a cavity larger than the electrode itself (allowing for the spark gap).
Flushing Techniques: Setting up nozzles to ensure "dead spots" don't cause a "DC Arch" (a continuous flame that ruins the part).
Day 3: Advanced Geometry and Finishing
The final day focuses on achieving the "mirror finish" and complex shapes that EDM is famous for.
Multi-Stage Burning: Using a "Rougher" electrode to remove 90% of the material, followed by a "Finisher" electrode for the final detail.
Undercuts and Side-Action: Using the CNC C-axis (rotating head) or lateral movements to burn shapes that are impossible for a traditional drill or mill.
Surface Finish (VDI/Ra): Calculating the parameters needed to achieve specific textures, from sandblasted looks to high-polish glass finishes.
Electrode Wear Compensation: Programming the machine to account for the fact that the "tool" (electrode) shrinks as it works.
