Overview:

I designed a Bracket to hold a filament run-out sensor i bought off ebay.
When the filament runs out, in this order it will:

1. Pause the print
2. retract filament to stop oozing,
3. move the head away to allow filament change
4. resume back where it initially stopped.

• It slips over the Extruder, and also has a cable holder integrated.
• The design allows it so you can use a small amount of PTFE tube to make it easier for the filament to guide into the extruder motor.
• Sensor Light up green when there is filament detected

-Sensor:
AliExpress: https://goo.gl/FutpoC

-Connectors for Raspberry pi:
http://r.ebay.com/9g8yce

-RaspberryPi running Octoprint

Setup Steps:

1. print out Filament Sensor and Lid
2. Install Sensor inside housing (will be a tight fit)
3. Wire up Sensor to Raspberry Pi. ( follow tutorial if stuck https://youtu.be/j7JfQXTf16U)
4. Install "Filament Sensor Reloaded" plugin on Octopi

Stock Firmware:

• Set Pin: 7
• Debounce Time: 400ms

• Switch type: Normally Open
  -Board Pin Mode: Board Mode
  Pause Print When Out of Fliament : (Tick)

  Now Edit Pause and Resume GCode (refer to photos below)

Firmware 1.10+

(Currently seems firmware is ignoring M600 L0, so please follow stock firmware setup if you manage to figure out how to stop m600 retracting the filament. please let me know in the comments)

• Set Pin: 7
• Debounce Time: 400ms
• Switch type: Normally Open
  -Board Pin Mode: Board Mode
  -Out of Filament GCODE: M600 E-5 L0 X10 Y10 Z5
  Pause Print When Out of Fliament : (No Tick)

updates:

(D,M,Y)

14/08/2017: Edited G-code pause function as the steppers were disabling after 60 seconds of the filament running out which led to printer loosing its coordinates. Now should stay on for 6 hours

14/08/2017: Better Lid design and better model design with smaller extruder cover hole, there should be no printing issues now.

27/08/2017: Added a dust cover for the extruder opening

up-coming:

• updated Gcode
• better lid design
• fixed model hollow slicing issues
• Printing without supports