It appeared that there was a fundamental mistake in the magnetic flow as given in figure 2 of KD 718. It isn’t allowed to have an iron pole in between two magnet poles. Report KD 718 has therefore been reviewed completely and frame size 112M is chosen instead of frame size 100. Now all four mechanical north poles are formed by magnets and all four mechanical south poles are formed by the iron of the armature. Chapters about other frame sizes are cancelled.

On 19-12-2022 a new chapter 6 has been added to report KD 718. The title of this chapter is: “Use of a 4-pole motor frame size 132 and 28 magnets size 50 * 20 * 5 mm”.