[FR] Add option for filament change gcode to go after first travel move on new layer

[ManuelMcLure]

Is your feature request related to a problem? Please describe. Usually, a new layer doesn't start at the same point the old layer finished - there's a X/Y travel move at the very beginning of the new layer just after the change in Z. The problem is that the M600 gcode for a color change is inserted before this travel move. This means that layer N finished, Z changes to the height of layer N+1, and then the M600 triggers. The printer moves to a park position, allows changing filaments, and then when the filament change is complete the printer moves back to the last position for layer N, often leaving a small bit of the new colored filament there. If this is on a top layer, there will be a noticeable blemish in the finished print.

Describe the solution you'd like Have an option to place the color change gcode after the first travel move on the new layer. This might leave a small spot of the previous color at that location, but it should be covered up by the new color when that starts extruding.

Describe how it would work Currently generated gcode example:

;LAYER_CHANGE
;Z:10.7
;HEIGHT:0.15
; LAYER: 70, Z HEIGHT: 10.7
G1 Z10.7 F7800
;COLOR_CHANGE,T0
M600
G92 E0
G1 E-0.7 F2400
G1 X62.169 Y97.508 F7800
G1 E0 F2400

Desired gcode:

;LAYER_CHANGE
;Z:10.7
;HEIGHT:0.15
; LAYER: 70, Z HEIGHT: 10.7
G1 Z10.7 F7800
G92 E0
G1 E-0.7 F2400
G1 X62.169 Y97.508 F7800
;COLOR_CHANGE,T0
M600
G1 E0 F2400

The M600 is after the retract, after the first travel move, and before the unretract.

Be as descriptive as your skill level allows you.

Describe alternatives you've considered Currently I use manual editing to change the location of the M600. It's possible that there may be a way to use a postprocessing script to move the M600 after the first travel move beyond the original location of the M600

[supermerill]

current & desired are the same?

[ManuelMcLure]

No - look at the position of the M600 - the current is just after the COLOR CHANGE comment, the desired is three lines down (after the G1 X62.169...)

[ManuelMcLure]

I've updated the gcode to move the comment as well as the M600 - it makes more sense that way.

[Triptikal]

Hello, I found out the same problem. Seems SuperSlicer puts the M600 command "in the middle of " the layer change instructions causing the printhead to print this layer "in the air" ( because in my case I'm adding 80mm to the Z to move the printhead in a "safe" place to execute the filament change ) before the next instruction of layer is given to the printer. It is resolved by manually move the M600 command just before the layer change instruction. The enhancement should be , from my pov, that superslicer should insert the M600 command before the layer change instruction.

The generated code by superslicer : ``G1 X142.009 Y143.673 E0.08266 ; Solid infill G1 X144.28 Y141.403 E0.14565 ; Solid infill ;LAYER_CHANGE ;Z:1.32 ;HEIGHT:0.28 ; custom gcode: before_layer_gcode ;BEFORE_LAYER_CHANGE ;1.32 G92 E0 ; custom gcode end: before_layer_gcode

;WIPE_START G1 F6240 G1 X143.361 Y142.322 E-0.95 ; wipe and retract ;WIPE_END G1 E-0.05 F4800 ; retract G1 Z1.32 F7800 ; move to next layer (4) ; custom gcode: layer_gcode ;AFTER_LAYER_CHANGE ;1.32 ; custom gcode end: layer_gcode

;COLOR_CHANGE,T0,#0ED51F ; custom gcode: color_change_gcode M600 ; custom gcode end: color_change_gcode

G1 E-1 F4800 ; retract ; acceleration to travel G1 X148.867 Y148.601 F7800 ; move to first Internal perimeter point (acceleration) ; decel to extrusion M204 S800 ; adjust acceleration G1 X150.515 Y150.48 ; move to first Internal perimeter point (deceleration) ; end travel G1 E1 F4800 ; unretract ;TYPE:Internal perimeter ;WIDTH:0.45 G1 F1511.1324 G1 X150.645 Y150.366 E0.00788 ; Internal perimeter G1 X150.756 Y150.297 E0.0059 ; Internal perimeter G1 X150.836 Y150.266 E0.00391 ; Internal perimeter`

Code after I moved the M600 command : `` G1 X140.997 Y145.188 E0.00402 ; Solid infill G1 X142.009 Y143.673 E0.08266 ; Solid infill G1 X144.28 Y141.403 E0.14565 ; Solid infill

;COLOR_CHANGE,T0,#0ED51F ; custom gcode: color_change_gcode M600 ; custom gcode end: color_change_gcode

;LAYER_CHANGE ;Z:1.32 ;HEIGHT:0.28 ; custom gcode: before_layer_gcode ;BEFORE_LAYER_CHANGE ;1.32 G92 E0 ; custom gcode end: before_layer_gcode

;WIPE_START G1 F6240 G1 X143.361 Y142.322 E-0.95 ; wipe and retract ;WIPE_END G1 E-0.05 F4800 ; retract G1 Z1.32 F7800 ; move to next layer (4) ; custom gcode: layer_gcode ;AFTER_LAYER_CHANGE ;1.32 ; custom gcode end: layer_gcode

G1 E-1 F4800 ; retract ; acceleration to travel G1 X148.867 Y148.601 F7800 ; move to first Internal perimeter point (acceleration) ; decel to extrusion M204 S800 ; adjust acceleration G1 X150.515 Y150.48 ; move to first Internal perimeter point (deceleration) ; end travel G1 E1 F4800 ; unretract ;TYPE:Internal perimeter ;WIDTH:0.45 G1 F1511.1324 G1 X150.645 Y150.366 E0.00788 ; Internal perimeter G1 X150.756 Y150.297 E0.0059 ; Internal perimeter G1 X150.836 Y150.266 E0.00391 ; Internal perimeter