Using wire-cut EDM for high precision pole tips

With customers demanding ever higher precision for pole tip shape, alignment and position, Wire-cut EDM machining is often used as a final finishing step.

The magnet components, less the coils, are assembled and keyed together. The pole tip profiles are then EDM wire-cut to size, ensuring any tolerance stacking from assembling multiple, individual components is eliminated.

Buckley Systems runs four, Sodick LQ series wire-cut machines, renowned as being among the most technically advanced and accurate available. Linear motors eliminate potential backlash, wear and oscillation associated with traditional ball-screw and servo drives while glass-scale encoders provide an instantaneous double-check of positioning accuracy. Cutting wire sizes range from 0.30mm (0.012”) diameter down to 0.15mm (0.006”) for fine work. With the lower wire guide able to move independently in three axes from the upper guide, tapers and profiles can be machined easily. Maximum cut depth is 400mm and the largest machine can accommodate material up to 1600mm wide. Our experienced operators provide the essential know-how to get the very best performance out of the machines. Extensive in-house research has been done on cutting exotic materials including low-carbon steel, high permeability alloys and laminated steel used in magnets.

Real-world experience has demonstrated that wire-cutting does not induce any “cross talk” between individual laminations that may happen with mechanical methods of pole shaping such as machining or grinding.

This piece was reprinted by D-Pace, Inc. from the Buckley Systems Spring 2020 technical bulletin with permission from Buckley Systems Ltd. It may not be reproduced in any form without permission or license from the source.