Eat this!

this is fully automatic, heavy duty, filament feeder!
it uses the motor from the automated build-platform to turn the spindle.
when the extruder has extruded enough filament and thus shortened the distance between the extruder and the spindle, a little switch is activated that gives a short impuls to a motor-control circuitry (also designed and prototyped by myself) which lets the motor run for about 1 second - enough for some minutes of printing...
(this motor-control also has a two-way switch for manual control of the motor and two indicator LEDs - green: forward, red: backward)
--- I did this because of problems with a very heavy spindle that I have where the extruder constantly has its problems turning the spindle on its own;
now I can do unattended prints of even the highest, biggest objects!