Today  two more upgrades for my good Prusa I3 B.

No 1: Infrared filament monitor. Detect filament blocking with routines to stop/pause 3D printer and let the user interact to solve the problem. This is an alpha development thing connected to an Arduino mini pro. It detects the movements of the little wheel and can count the movements (meters) the filament made.

No 2: Bracket for Saintflint bowden extruder including a holder for a 40mm fan.

Works with one old (discontinued) Pololu QTR-1A Reflectance Sensor.