N3P mmu poop ejector V2

UPDATE 2025-06-21 :

Increase space where poop exit and added a little rib to help keep the filament inside and made it stronger.

 

N3P mmu poop ejector for Filametrix depressor mod

Make smaller, more compact poop that are easier to manage.

 

BOM:

I used a this servo cause I had it on hand but can work with any 9g servo.

Used the stock servo arm that came with the servo.

Need 4 M2x6 Hexagon Hex Socket Cap screw.

Covered the slide with a sheet of metal from a EXCEL mint can that I glue on, It help cooling the plastic and slide better.

Macros that I use. Adapt to your installation.

[servo EJECTOR]
pin: #Servo pin
initial_angle: 80                                     
maximum_servo_angle = 180
minimum_pulse_width = 0.0005
maximum_pulse_width = 0.0024
[gcode_macro _EJECTOR_DOWN]                               # Deploy Brush
gcode:
   SET_SERVO SERVO=EJECTOR ANGLE=35               # At 75 for me the brush is under the nozzle
[gcode_macro _EJECTOR_UP]                                # Retract Brush
gcode:
   SET_SERVO SERVO=EJECTOR ANGLE=80                # Set at 8 for me so that my cheap servor is not strugling at 0 I hear it strugling to close more
[gcode_macro EJECTOR_EJECT]                                # Retract Brush
gcode:
   _EJECTOR_DOWN
   G4 P500                                               # Dwell 500 millisecond
   _EJECTOR_UP

 

[gcode_macro CLEAN_NOZZLE]
gcode:
  M117 Cleaning nozzle
  {% if printer.toolhead.homed_axes != "xyz" %}       # Check if printer is home and if not home it
        G28
  {% endif %}
  SAVE_GCODE_STATE                                    # Save printer position
  G91
  G1 Z4 F1200
  G90 
  G1 X-17 F5000
  EJECTOR_EJECT                                       # Eject poop
  G1 X-5 F500
  EJECTOR_EJECT                                       # Eject poop
  _BRUSH_NOZZLE                                       # Clean nozzle
  RESTORE_GCODE_STATE MOVE=1 MOVE_SPEED=50            # return to starting position

[gcode_macro _BRUSH_NOZZLE]
gcode:
  G90
  G1 X-17 F5000
G1 X-5 F5000
  G1 X-17 F5000
G1 X-5 F3600                                       # speed decrease
  G1 X-17 F3600
  G1 X-5 F3600 
  G1 X-17 F500
  G1 X-5 F500 

 

Added in Happy-Hare mmu_macro_vars.cfg

variable_user_pre_load_extension      : 'EJECTOR_EJECT'; Executed after default logic
variable_user_post_load_extension     : 'CLEAN_NOZZLE'; Executed after default logic but before restoring toolhead position