Sodick Flat Linear Motors in EDM
Electrical Discharge Machining is fundamentally a gap-control process.
The machining speed, stability, and surface quality depend directly on how accurately the machine can maintain the optimal spark gap between the electrode and the workpiece. This is where flat linear motors in Sodick EDM provide a decisive advantage.
By eliminating mechanical transmission components such as ball screws, Sodick EDM machines achieve instant servo response, zero backlash, and exceptionally stable gap control. As a result, Sodick EDM machines deliver higher cutting efficiency, improved surface quality, and long-term positioning accuracy, making flat linear motor technology a key factor in their superior performance.
Flat linear motors are what EDM have been missing since the very beginning
The gap between magnets and coils in Sodick Flat Linear Motors is always = 0.4 mm
Sodick flat linear motors are free from backlashes, lost motions, wide dead zones, stick-slips and bumpy feeds
Conventional ball-screw drives, due to large losses in the mechanisms for converting rotational motion into linear motion and inertia (backlashes, dead zones) provide feed to command points only with a wide approximation invariably missing the ideal command point. As a result a ball-screw EDM only a small part of the time works for with the optimal spark gaps and, accordingly, in optimal energy modes (maximum productivity modes).
The tool in EDM process is electric spark. Or controlled spark discharges of various intensity and other parameters. Spark discharges are generated in the inter-electrode gap or the gap between a workpiece and an electrode.
Characteristics of spark discharges to a very large extent depend on the size of the spark (inter-electrode) gap. The optimal gap means optimal processing conditions and, therefore, maximum productivity and machining quality. If the gap is larger or smaller than necessary, productivity and quality are lost. Ideally, at each moment of the working servo feed, the gap should be equal to the command value (commanded by the CNC).
The servo system continuously adjusts the electrode position to maintain the optimal spark gap.
Ideal structural rigidity
Both the panels of magnets and the blocks of EM coils of Sodick planar linear motors are rigidly mounted to the massive structures of the machines, which completely eliminates any deformation of the parts of the linear motors and machine tools. Massive cast iron structures to which the EM coils are mounted ensure perfect heat dissipation.
A Sodick machine-tool with flat linear motors is a unified mechatronic system
Sodick flat linear motors allow EDM machines to maintain the optimal spark gap almost continuously — something conventional ball-screw machines cannot achieve.
In linear motors, there is no conversion of rotational into linear motion, no ball screws, no gear or belt reducers. The motor moves with the moving part. The dead zone is almost negligible. Feed accuracy reaches microns and fractions of a micron with instantaneous corrections of electrode position when gap state changes.
As a result, the gap is continuously kept in a state maximum of the ideal and at each moment constantly changing sparking discharges are maintained at the ideal energy state. This is what ensures a sharp increase in both the productivity and the quality of EDMing.
Sodick Flat Linear Motors are a GAME-CHANGER in EDM construction
Flat Linear Motor Benefits in Real EDM Production:
In EDM, machining performance depends not only on positioning accuracy, but on how quickly and precisely the machine can respond to constantly changing gap conditions.
- More stable cutting in difficult machining conditions
- Reduced wire breakage risk
- Higher achievable cutting speeds
- Consistent surface quality over long machining cycles
- Reliable accuracy retention over many years of operation
- Lower maintenance requirements compared to mechanical drive systems
