The reason why the workpiece processed by the electromagnetic centerless fixture is oval is because after the workpiece is positioned on the front and rear supports, the end face of the workpiece is tightly attracted to the end face of the magnetic pole by the suction force generated by the DC electromagnetic coil, and the workpiece has a certain eccentricity e. When the magnetic pole rotates around its axis O, it forces the workpiece to rotate around its own center O'. Because of their eccentricity, there is relative sliding between the magnetic pole and the workpiece, so the magnetic pole produces a friction torque and a friction resultant force F, which passes through O' and is perpendicular to O'. The former forces the workpiece to rotate, and the latter makes the workpiece cling to the front and rear supports, thus making the workpiece obtain stable rotary motion.

Adjustment parameters of electromagnetic coreless fixture: eccentricity e has certain influence on machining. From the influence curve of Ki(Ke) obtained from the experiment (Figure 5-33), it can be seen that when the E value is 0.2mm, it has no influence on the machining accuracy; However, when E≤0.2 mm, especially E.