Topic: Ice maker inspired filament out detector idea.
You know how most refrigerator ice makers have a bar that can fall down when the ice is low, but is held up by the ice when the tray is full?
I was thinking that idea might work for a filament out detection system.
Have some rings on the PVC pipe that holds the spool, and run something really light (balsa, drinking straw, etc) from the rings across the face of the spool. The filament coming off the spool would keep the straw from falling all the way down and rotating the rings, once the filament runs out, the straw could fall, the rings would rotate and something like two pieces of aluminum foil or coils of copper wire could make contact and alert you to the filament being out.
Make it light enough, and it would almost certainly involve less drag on the filament than the schemes that run it through a small hole past a microswitch.
I'll probably try this someday soon (the problem is fitting it in with all the other things I want to try :-).
