I've been wanting a runout sensor forever and I finally designed my own. This is a hybrid inspired by what others in the BLV asnd Hevort communities have made.

My main design goals:

• Limited/affordable BOM
• Adjustable tension, one problem with many smart filament sensors is that they put too much drag on the filament, or not enough and they're not able to read any pulses. This sensor has a "lead screw" that allows adjusting how much tension is put on the wheel by the filament.
• The encoder wheel should properly spin on bearings

BOM
2x M3x40mm
2x M3 nyloc nuts
2x M3x5mm
2x M3 nuts
V-roller wheel (or print it from tpu, pla or otherwise might work)
2x F623 bearings
Lerdge optical end stop

For mounting:
2x M3x8mm
2x M3 t-nuts

My current configuration in RRF to support this, but not yet fully tuned:
M591 D0 P7 C"^io3.in" S1 R70:170 E11.445 A0 L3.815

BLV cube

No

No

200

13

No supports needed, except for the encoder wheel, the bearing recess should be supported to allow it to print cleanly. This makes installing the bearing easier, it's doable without supports, but that cleanup is more effort than removing support.

Primarily tested in PLA+ at the moment, will consider revisiting and designing for ABS/PETG as required.