Motor Brush Cap BERNINA 730/530 Record

thingiverse

I own a Bernina 732 Record which I used to build an embroidery machine. One of the carbon brush caps broke so I designed a replacement part. I found the a metric M6 thread cut into a 8.4mm hole to fit the thread well. There is a V1 without a slot for a screw driver and one with a slot. The one with a slot is useful for the brush on the bottom side of the machine because you cannot tighten that one by hand without taking off the motor completely. The slot has two chamfers on the bottom so it can be printed without supports on its "head". My motor is of type PSE-4C (1964-1967). Its predecessors were the HG-NM6/7 which look very similar so the cap fits probably also there. The sewing machine Bernina 530 Record has also different motors most of which are also similar in style to the PSE-4C. It almost looks as if the assembly which holds the brushes was the same all along so there is a high chance tha caps will fit also there although I did not test that! Note that under prolonged use of the motor during embroidering for example the brass thread might get warm and deform the cap such that it becomes loose. So choose a filament with a high melting point if possible. Happy sewing! :)