The mass in a seismic sensor is mounted on two pivots that form an axis which is held within a frame. The precision of this assembly is critical to measuring earthquakes to the high degrees of accuracy that our customers require.

To achieve this requirement, the pivots must be attached from two perfectly concentric holes drilled on opposite sides of the frame.

Traditional methods of metal machining can stress or distort the metal, so at Güralp we have invested in a wire Electrical Discharge Machine (EDM) that enables us to cut the holes in our components, in-house, to ensure we deliver the optimum results.

What is wire EDM?

Wire EDM is a non-contact machining process that removes material from the workpiece using sparks from an electric current. As no physical force is applied that might distort or impact the workpiece the material remains relaxed, stable and consistent, reducing the early life settling process for the sensor.

How does it work?

The wire EDM uses a 0.25mm thick brass-based wire fed from a cylindrical spool, through a series of pulleys above the machine, where it is straightened and inserted into the cutting tip via a water jet.

During operation, the basin of the wire EDM is flooded with deionised water that submerges the workpiece being cut. Deionised water has a low viscosity so doesn’t conduct an electric charge, allowing the sparks to cut through the metal. The water also acts as a coolant to prevent heat from transferring into the metalwork and warping the hole being cut. A jet of the water is also flushed around the wire, to remove any debris that may affect the cutting.

The wire EDM can effectively cut through any metal from copper and brass to steel and carbide.

By bringing this capability in-house, we reduce lead times for components and improve quality assurance, so our customers can be confident in the performance of our instrumentation.