Filament feed indicator

thingiverse

I made this after several filament feed failures on long prints. I monitor my printer using Babycam which lets you use a phone camera via WiFi to check up on progress. However you cannot tell if the filament is feeding successfully. In my simple design I pass the filament over a simple roller/wheel which acts as a light gate. the bracket has holes which allow light from an LED to pass through the wheel and onto the Light dependent resistor on the other side. As filament is pulled off the wheel turns changing the input voltage to the Arduino Nano. The Nano then turns on an output pin to a further LED for displaying close the camera. If all is well the LED will turn on and off as filament is fed. If it stays on or stays off for long periods you have a feed error. You could also add an alarm to detect long on or off periods.