Force-current relationship important when using linear motion for part production

Accuracy and precision of machine axis movement is paramount in achieving the tolerances and surface finishes required in today’s part-production environment. Final part dimensioning, surface finishing, and mill cutters sharpening is often only possible through grinding operations. Grinding is a demanding machining operation that involves significant vibration, heat generation and abrasive particle creation, while needing to maintain positional and speed accuracy of the movement. Selection of the axis translation mechanism will determine the level of accuracy possible along with the cost of machine ownership.

A basic need of the machine design is to be able to go to a position, and knowing where that position is relative to the workpiece. In looking at achieving accuracy in the movement of a workpiece or the tooling, there are three areas of the machine design: the mechanical components, the command and control of the movement (control boards and servo loop), and the translation mechanism (linear motor or rotary motor and ball screw). This article is focused on one aspect of translation, specifically the force generated by linear electric motors.

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