Small UBBI filament sensor

Works with every type of filament as long as it's approximately 1.75mm in diameter, is low friction and small

BOM:

• Kailh Black GM 8.0 Microswitch or equivalent
• 4mm Ball Bearing (or unpack a 608zz bearing)
• M3x6 BHCS
• small cable tie to prevent cable degradation

Additionnal requirements:

• Soldering equipment
• some cable to connect the switch
• Hardware pullup pin available on the printer mainboard (most filament sensors already use one)

Recommended print settings same as standalone UBBI connector:

• Nozzle diameter: 0.4mm
• Layer height: ≤ 0.2mm
• Reverse on odd: disabled
• Precise walls: enabled
• Wall order: i/o/i
• Tolerance requirement: 0.1mm
• Print orientation: as imported
• Supports: included with the model, enable support generation and change to manual placement, don't add anything

Recommended materials same as standalone UBBI connector:

• PETG
• ABS/ASA

Instructions:

• Place the bearing ball in the small hole next to the filament path
• insert the micro switch and make sur it is aligned with the ball
• solder wires to the outer microswith pins (polarity doesn't matter)
• Use the screw to keep the switch in place, make sure not to tighten it too much 
• If you don't have a sacrificial endstop cable, crimp the wires and attach a JST connector
• Hook up the cables to ground and endstop

Software config (klipper only):

switch_pin: ^!(the pin you are using)

If the sensor is working in reverse (detecting filament when empty) you just have to remove the ! from the pin definition.

Uses the filament sensor of the pico mmu filament hub with ubbi connectors