How to Start a Sinker EDM Job on the G-EDM

While many are familiar with the G-EDM's capabilities, it’s worth noting that the machine supports both wire and sinker EDM operations. Unlike wire EDM, sinker EDM does not require a GCode file; instead, it relies on the machine’s firmware to generate the necessary motion commands.

Understanding Sinker EDM Operation

Currently, sinker EDM is performed with a single axis moving in a single direction. After selecting the appropriate settings, such as cutting depth, axis, and direction, the firmware automatically generates the required GCode command.

The process begins with the selected axis performing an initial probe to establish the workpiece’s zero position. Once this is obtained, the machine moves along the axis for the specified cutting depth, calculated from the probe point.

Step-by-Step Guide to Starting a Sinker EDM Job

1. Access the User Interface

The front screen of the G-EDM user interface provides all necessary controls and settings. By default, the machine operates in wire EDM mode, so the first step is to switch to sinker mode.

2. Switch to Sinker Mode

Tap the MODE button on the touchscreen to open the mode menu.
Select "Sinker EDM" from the options. The button will highlight, indicating the active mode.
The front screen will update to reflect sinker mode. This selection is stored in the ESP memory and will persist after rebooting.

3. Set Basic Parameters

Cutting Depth: The default is 10 mm. Since sinker mode currently does not involve probing for the cutting depth, this value represents the total travel depth after the initial probe.

Adjust if needed: For example, set it to 50 mm for a deeper cut:

• Enter the desired value.

• After the initial probe, the machine will move into the workpiece by this distance and then stop.

4. Confirm Axis Selection  

Typically, sinker EDM uses the Z-axis (default). However, other axes like X or Y can also be used.
Note: If you run the XYUV or XYUVZ configuration, selecting X or Y axes for sinker operation will chain axes together (e.g., XU or YV) to run a straight line without tilting the wire.
This is the only setting that is not persistant. It will always be Z down after powering the machine on.

5. Optional: Use the Wire Module for Straight Cuts

If the wire module is installed, you can perform straight-line cuts with the wire in sinker mode.
This feature allows quick, GCode-free straight cuts, which can be very useful.

6. Run the Line    

Close the settings menu and head back to the frontscreen. Turn the Motionswitch (On/Off rocker switch) to On to unlock the motion and press the start button on the screen at the right bottom. It will then start. Turning the motion switch off will always stop the process.

Additional Settings and Tips

Flushing and Dirt Removal

Sinker EDM creates pockets that can accumulate debris.
To maintain cutting quality, periodic flushing motions are recommended.
You can configure flushing intervals and travel distances in the settings menu under the Flushing section.
After each flushing retraction, the machine returns to the initial position, offset by a configurable number of motor steps (offset steps) to prevent collisions while returning.

Configuring Flushing:   

• Interval: Set how often the flushing motion occurs (e.g., every 2 seconds).
• Distance: How far the axis moves during flushing.
• Disabling Flushing: Set interval to zero to disable this feature.

The flushing settings are in the settings menu:

Summary

• Switch to sinker mode via the Mode menu.
• Set your desired cutting depth.
• Ensure the correct axis is selected.
• Adjust flushing settings if necessary.
• Proceed with probing and cutting as usual.