EDM Servo Valves and Components

“Understanding, Maintaining, and Repairing”

The spark gap of the electrode and the workpiece of a Sinker EDM machine creates an electrical signal that is processed by the servo circuitry,  then sent to the hydraulic servovalve (hence the name, electro-hydraulic servovalve). This signal causes the valve to react, altering the flow of the hydraulic fluid to the main cylinder. This causes the ram or quill that carries the electrode, to proceed forward or to momentarily retract to clear the gap of debris. This reaction is instantaneous and is meant to maintain an ideal steady cut, resulting in the fastest possible EDM job, in respect to the parameters set by the operator. This all happens hour after hour, day after day, if the servovalve is working properly.

Wire EDM Applications with CNC Mills (Bridgeport, Fadal, and Okamoto etc), Die Spotters, and Double Headed Cutters have Electro-hydraulic Servomotors, Cylinders, Pumps, and Encoders, which are serviced here at ISHI.

If you are experiencing sluggish responses or complete lock up of the servovalve spool due to contamination or experiencing any servovalve related problems; call our customer service department or e-mail us for assistance. If you wish, you may remove your components and send it to us for evaluation and repair.

Before installing your repaired servovalve, you should consider cleaning out the tank, replacing the filter, and changing the hydraulic fluid. A special valve that manually duplicates the action of the servovalve should be mounted in place of the servovalve for this operation. This valve is called a Flushing valve.


EDM Servovalves are in inventory for immediate delivery