Early Warning Filament Low Sensor

This sensor gives you an early warning when your filament reel is starting to run low. It can be used on its own or with a filament runout sensor and does not require any modifications to the printer. It avoids aborted prints or having to change a spool mid-print.

Some cardboard and most big plastic reels have closed sidewalls making it difficult to see how much filament is left over, sometimes we just get distracted and don’t pay attention…

##Design Features##
- Stand-alone, battery powered audible alarm
- Adjustable sensor does not tangle filament
- Multiple mounting options
- On/off switch and separate test button
- Very simple circuit
- Uses common mechanical and electronic parts
- Simple prints with few supports and easy clean-up

##Print and Assembly##
- Uses a 608 bearing that’s open or shielded (ZZ), but not sealed (RS/2RS)
- Feed the wire through the arm’s slot before adding the end protectors
- You MUST attach the arrow and protector to the ends of the wire