ExtrusionLengthGauge

This device shows the length of extruded filament for calibrating the extruder steps. The big wheel requires 200 mm of 1.75 mm filament to run along the circumference for a full rotation. The small arrows are 10mm apart each, the long arrows mark 100 mm.

To calibrate the extrusion, thread the filament between the wheels, set a long arrow on the marker and send an "extrude 100 mm" command to the printer.

If the actual length falls short of the marker or overshoots, adjust the E steps accordingly, align the long arrow again and repeat until you're happy with the result.

The holes and mounting pins are meant for 608 type bearings (22 x 7 x 8 mm). Fixate them with short M4 screws and washers.