Quote Originally Posted by AbuMaia View Post
... I should probably make something like that as well, using a short bit of teflon tubing as the "detector" part, attached to a switch. I already have a switch connected that pauses the print and moves the hotend if the filament runs out. I can just wire the bulge switch in series, which will pause the print so I can sand down the bulge.
I've also thought about merging the no-filament and fat-filament functions. On the bulge detector, I'm waiting for some PTFE Bowden tube to play with. In the mean time, I've been thinking a simple plate with say #49 (1.854mm) and #48 (1.93mm) holes drilled in it to provide some flexibility. The bottom of the plate hinged and the top of the plate resting against a microswitch. If a bulge doesn't fit through the hole, it tips the plate forward just a bit to trigger the switch and an alarm goes off. Slide the detector mechanism toward the printer a bit, and clean away enough of the bulge to clear the hole and move the detector back towards the spool. All without stopping the print if I'm in the area.

Where do you explain how you manage the print pause and hot end move? I haven't been thinking about that part yet.