Problem unloading filament using M600 gcode on the MK3
I'm using an MK3 to print a multicolored object. I'm using the normal method for doing this for a MK3, namely, using the M600 gcode. Although I'm not using Prusa Control for this, I'm using the same technique that it uses. That is, in the gcode, I insert an M600 gcode command just after the appropriate layer change. I insert the code at exactly the same place as Prusa Control does. For example, if the original gcode is
...
;AFTER_LAYER_CHANGE
;0.2
; PURGING FINISHED
G1 X145.669 Y102.152
G1 Z0.200
G1 E0.80000 F2100.00000
M204 S1000
G1 F1800
G1 X145.862 Y101.884 E0.01033
G1 X146.096 Y101.651 E0.01037
...
the modified gcode becomes
...
;AFTER_LAYER_CHANGE
;0.2
; PURGING FINISHED
G1 X145.669 Y102.152
G1 Z0.200
G1 E0.80000 F2100.00000
M204 S1000
]M600 ; filament change command
G1 F1800
G1 X145.862 Y101.884 E0.01033
G1 X146.096 Y101.651 E0.01037
...
This works as it should --- at the appropriate time, the tool stops printing, moves to the front right corner of the bed, and the LCD asks me to press the knob to unload the filament. This is where the problem occurs: For one kind of filament, the unloading fails, and the filament gets jammed. eSUN ABS+ filament works fine, but eSUN ABS fails to extract. It's really weird; the filament unloads fine from the LCD menu normally, but not when using the M600 code, at the some temperatures.
Any ideas about why I'm having trouble?