I saw on a popular site simple indicators for attaching to the axle of an extruder motor (Prusa printers). Those gadgets are spinning due to movement of motor, both clockwise (pulling filament) or counterclockwise (retracting). But all of those things are attached to motor axis by small neodymium magnet (round, 8x3 mm). I searched informations how such magnets affects for stepper motors and I read that magnet field can significantly change magnetic field of the motor. On presented movies for gadgets which I saw, the motor seems to have no trouble with rotating but AFAIK neodymium magnets have really strong magnetic field and I am curious how its centric orientation due to motor axis:
- inhibits rotation
- if yes, how much it raises the temperature of motor?
- how it affects for electronic of filament sensor?
Currently I use Prusa i3 MK3 printer and during long (~10h) printings an extruder motor is enough hot and I don't want make it hotter. I want to print and attach such "rotation indicator" but the fact of used magnets made me started to thinking about magnetic field of motor. Or maybe those changes are so marginal to think about them?