When traditional machining methods reach their limit, electric discharge machining can be the answer. The EDM process allows for high accuracy and is applicable for any conductive material.
Brief introduction of EDM
Electrical discharge machining, or EDM, is a non-traditional method in which material is removed from a workpiece using thermal energy. Much like processes such as laser cutting, EDM does not need mechanical force in the removal process. It is the reason why it is considered non-traditional contrary to, for example, the processing with cutting tools.
In tool and mold making, EDM is very popular due to its applicability for hard materials like titanium or for in particular complex shapes that are hard to achieve with milling.
The process principle of EDM
When the voltage between the two electrodes is increasing, the intensity of the electric field in the volume between the electrodes becomes stronger, causing the dielectric breakdown of the liquid, and produces an electric arc. As a result, the material is replaced by electrodes. Once the current stops (or is stopped, depending on the type of generator), a new liquid dielectric is conveyed into the inter-electrode volume, enabling the solid particles (debris) to be carried away and the insulating properties of the dielectric to be restored. Adding a new liquid dielectric in the inter-electrode volume is commonly referred to as flushing. After a current flow, the voltage between the electrodes is restored to what it was before the breakdown so that a new liquid dielectric breakdown can occur to repeat the cycle.
Maintenance of EDM
Daily inspection and maintenance：
1. Clean the dirt of machine tool and guide rail every day to keep the bed clean; turn off the air source and power supply when off duty.
2. If you leave the machine for a long time, turn off the power to prevent non-professional operation.
3. pay attention to observe whether there is lubricating oil on the surface of the horizontal and longitudinal guide rail and rack of the machine, to keep it well lubricated!
Weekly inspection and maintenance：
1. Every week to carry out a comprehensive cleaning of the machine, horizontal and longitudinal guide rail, transmission gear rack cleaning, filling lubricating oil.
2. Check whether the horizontal and vertical rail eraser is working; if not, replace it in time.
3. Check whether the cutting torch is loose, clean up the garbage at the muzzle of the ignition gun, and keep the ignition normal.
4. If there is an automatic raising device, we should consider whether the detection is sensitive and whether to replace the probe.