Autopowered fans or what!??! LOL (check video inside! LOL)

[bolsoncerrado]

Just got my extruder replacement and while playing with the bed ( changed kapton tape) i noticed this!



Do we have a dynamo inside our RapideLites? LOL

Joao, any thoughts?

[Joao]

Every electromagnetic motor also generates electrical energy when applied the mechanical movement. These stepper motors are like that, and very efficient.

This PCB design could have prevented that placing some diodes making sure the current would not 'come back' from the motor, but maybe it was needed to get the feedback of the stepper motor (position, speed, etc). Its not a very critical thing.

This feature is also used with some robots, where they can 'learn' a position, and that is by reading the movement of the motor with its energy generated.

Its strange that mine does not do that...

[JonatanJacobsson]

Ive noticed this too! I think that when your using force to push the printbed -> spin the stepper motors -> generate electricity. And since they probably are on the same circuit the power transfers to the fans.

[grobbins]

Yes mine does this as well. I first noticed it while assembling my printer as I saw the blue led from the power button light up for a second.

[bolsoncerrado]

haha amazing Joao, thanks for the tech explanation