Filament Sensor V2

This is a revision to my other filament sensor design. Notable changes:

1. Smaller design with the use of smaller bearings.
2. Repurposing the z-limit switch that I no longer needed.
3. Very low drag, even when with high Z values.

The bearings I used here to harvested from a spare POM wheel.

Also note that depending on slicer settings and filament uses, you may need to do some sanding or tweaking to get the bearing carrier to move without getting hung up.