Automatic nozzle cleaning (Prusa Mini)

Alternative way how to clean the nozzle (in 30s)

This method uses the stickiness of filament to catch stuck filament from the nozzle exterior. 

1. Prints small disc (as in 3mf file)
2. Extrude 25mm of filament with nozzle 0.5mm from the bed.
3. Retract 5mm
4. Wait for blob to cool off to 180°C
5. Pull hotend up, leaving plastic down
6. done!

This was tested for PLA, but it should be fine also for PETG filament. It could clean PETG from nozzle pretty well (need to be tested). 

How to use - options

• recommended: get 3mf project and slice it youself - check if there are custom Gcodes under Printer Settings/End G-code
• OR, run the uploaded gcode
• OR, make your project with a shape at X170 Y10 0,2mm tall, and add custom gcode to Printer Settings/End G-code. Code is listed below.

Demonstration

Blob forming:

Cleaning action:

Custom GCODE listing:

G1 X170 Y10 Z0.5 ; Move to 170,10,0.5
G1 F200 E25 ; Extrude filament at a 200mm/min, 25mm
G1 E5 F4200 ; Retract 5mm
M104 S180 Start cooling down to 180C
M109 R180 ;Wait for nozzle 180C.
G1 Z10 F720 ; Move Z-axis up 20m
G1 Y50 F4200 ; get out of the way so it can drop in the end.