MMU v1

Uses the following gcode so the filament will be removed.

G1 E-1 F7200    
G91
G1 Z5 F1200
G90
M220 S100               ; Set override speed to 100%
G1 X0 Y200 F2400    
G1 E5 F150
G1 E-15 F5600               ; Initial retract to get filament out without stringing
G1 E-10 F1000       ; retract filament in PTFE tube ( stages)
G1 E-10 F240
G1 E-10 F100
G1 E-10 F40
G1 E-10 F2000
G1 E-30 F2000       ; Remove filament to above drive pulley
M702 C          ; Unload filament
G4 S1           ; pause 1 second
M107            ; turn off fan
M104 S0         ; turn off temperature
M140 S0         ; turn off heatbed
M84             ; disable motors

MMU v2

use the following gcode so the filament will be removed.

G1 E-1 F7200    
G91
G1 Z5 F1200
G90
M220 S100               ; Set override speed to 100%
G1 X0 Y200 F2400    
G1 E5 F150
G1 E-15 F5600               ; Initial retract to get filament out without stringing
G1 E-10 F1000       ; retract filament in PTFE tube ( stages)
G1 E-10 F240
G1 E-10 F100
G1 E-10 F40
G1 E-10 F2000
G1 E-30 F2000                   ; Remove filament to above drive pulley
M702 C          ; Unload filament
G4 S1           ; pause 1 second
M107            ; turn off fan
M104 S0         ; turn off temperature
M140 S0         ; turn off heatbed
M84             ; disable motors