The drawing on the left depicts the machine starting or “0” point for easy and automatic positioning attainable in a sinker EDM, on a sine plate, as described in the earlier EDM sinker setup page. As mentioned there, the balls are zeroed on the centerlines of one another. Here it is illustrated how in doing that, the outside surfaces of the two balls remain constant regardless of the angle or even compound sine angle being set.
The drawing on the right shows a gate electrode in position to EDM the gate exactly as engineered in the cavity component. Since the gate is on the centerling we are only showing the X move and the Z finish EDMing position. These offsets will be direct numbers entered into the controller from the “0” position. It is therefore clear to see how the exact position the gate will come through, and the finished size of the gate itself can be pinpointed with extreme accuracy engineering with this methodology. remember, the gate electrode would also have been engineered, manufactured, and inspected/certified to the gage ball.