No longer working with BambuStudio 2.1.x

[spuder]

I've been using this custom gcode successfully for many months in my TPU print farm and it has been a major time saver.
With the latest release of bambu studio (2.1.x), The change filament gcode no longer works, Instead the printer will ignore the pause and will not attempt to cut filament or change tools

I'm using the older code from redddit as the latest fails (see #15)

Custom GCode

; change filament without AMS g-code
{if toolchange_count > 1}
M204 S9000 ; set starting acceleration
G17 ; set CNC workspace plane
G2 Z{max_layer_z + 0.4} I0.86 J0.86 P1 F10000 ; spiral lift
G1 Z{max_layer_z + 3.0} F1200 ; vertical lift

; move to poop chute
G1 X70 F21000
G1 Y245
G1 Y265 F3000
M400

; turn off fans P1 and P2
M106 P1 S0
M106 P2 S0

; wipe?
G1 X90 F3000
G1 Y255 F4000
G1 X100 F5000
G1 X120 F15000

; move to position to prep for cutting filament
G1 X20 Y50 F21000
G1 Y-3
; always use highest temperature to flush
M400
M109 S[nozzle_temperature_range_high]

; cut filament
G1 X5 F300
G1 X20 F12000

; move to poop chute
G1 X70 F12000
G1 Y245
G1 Y265 F3000

; push a little filament out and then retract out
G1 E10 F200
G1 E-10 F200
G1 E-20 F500

; pause for user to load and press resume
M400 U1

; don't know when next_extruder is >=255, so this may always activate?
{if next_extruder < 255}
M400

G92 E0
{if flush_length_1 > 1}
; FLUSH_START
{if flush_length_1 > 23.7}
G1 E23.7 F{old_filament_e_feedrate} ; do not need pulsatile flushing for start part
G1 E{(flush_length_1 - 23.7) * 0.02} F50
G1 E{(flush_length_1 - 23.7) * 0.23} F{old_filament_e_feedrate}
G1 E{(flush_length_1 - 23.7) * 0.02} F50
G1 E{(flush_length_1 - 23.7) * 0.23} F{new_filament_e_feedrate}
G1 E{(flush_length_1 - 23.7) * 0.02} F50
G1 E{(flush_length_1 - 23.7) * 0.23} F{new_filament_e_feedrate}
G1 E{(flush_length_1 - 23.7) * 0.02} F50
G1 E{(flush_length_1 - 23.7) * 0.23} F{new_filament_e_feedrate}
{else}
G1 E{flush_length_1} F{old_filament_e_feedrate}
{endif}
; FLUSH_END
G1 E-[old_retract_length_toolchange] F1800
G1 E[old_retract_length_toolchange] F300
{endif}

{if flush_length_2 > 1}
; FLUSH_START
G1 E{flush_length_2 * 0.18} F{new_filament_e_feedrate}
G1 E{flush_length_2 * 0.02} F50
G1 E{flush_length_2 * 0.18} F{new_filament_e_feedrate}
G1 E{flush_length_2 * 0.02} F50
G1 E{flush_length_2 * 0.18} F{new_filament_e_feedrate}
G1 E{flush_length_2 * 0.02} F50
G1 E{flush_length_2 * 0.18} F{new_filament_e_feedrate}
G1 E{flush_length_2 * 0.02} F50
G1 E{flush_length_2 * 0.18} F{new_filament_e_feedrate}
G1 E{flush_length_2 * 0.02} F50
; FLUSH_END
G1 E-[new_retract_length_toolchange] F1800
G1 E[new_retract_length_toolchange] F300
{endif}

{if flush_length_3 > 1}
; FLUSH_START
G1 E{flush_length_3 * 0.18} F{new_filament_e_feedrate}
G1 E{flush_length_3 * 0.02} F50
G1 E{flush_length_3 * 0.18} F{new_filament_e_feedrate}
G1 E{flush_length_3 * 0.02} F50
G1 E{flush_length_3 * 0.18} F{new_filament_e_feedrate}
G1 E{flush_length_3 * 0.02} F50
G1 E{flush_length_3 * 0.18} F{new_filament_e_feedrate}
G1 E{flush_length_3 * 0.02} F50
G1 E{flush_length_3 * 0.18} F{new_filament_e_feedrate}
G1 E{flush_length_3 * 0.02} F50
; FLUSH_END
G1 E-[new_retract_length_toolchange] F1800
G1 E[new_retract_length_toolchange] F300
{endif}

{if flush_length_4 > 1}
; FLUSH_START
G1 E{flush_length_4 * 0.18} F{new_filament_e_feedrate}
G1 E{flush_length_4 * 0.02} F50
G1 E{flush_length_4 * 0.18} F{new_filament_e_feedrate}
G1 E{flush_length_4 * 0.02} F50
G1 E{flush_length_4 * 0.18} F{new_filament_e_feedrate}
G1 E{flush_length_4 * 0.02} F50
G1 E{flush_length_4 * 0.18} F{new_filament_e_feedrate}
G1 E{flush_length_4 * 0.02} F50
G1 E{flush_length_4 * 0.18} F{new_filament_e_feedrate}
G1 E{flush_length_4 * 0.02} F50
; FLUSH_END
{endif}
; FLUSH_START
M400
M109 S[new_filament_temp]
G1 E2 F{new_filament_e_feedrate} ;Compensate for filament spillage during waiting temperature
; FLUSH_END
M400
G92 E0
G1 E-[new_retract_length_toolchange] F1800
M106 P1 S255
M400
G1 X80 F15000
G1 X60 F15000
G1 X80 F15000
G1 X60 F15000; shake to put down garbage

G1 X70 F5000
G1 X90 F3000
G1 Y255 F4000
G1 X100 F5000
G1 Y265 F5000
G1 X70 F10000
G1 X100 F5000
G1 X70 F10000
G1 X100 F5000
G1 X165 F15000; wipe and shake
G1 Y256 ; move Y to aside, prevent collision
M400
G1 Z[z_after_toolchange] F3000
{if layer_z <= (initial_layer_print_height + 0.001)}
M204 S[initial_layer_acceleration]
{else}
M204 S[default_acceleration]
{endif}
{else}
G1 X[x_after_toolchange] Y[y_after_toolchange] Z[z_after_toolchange] F12000
{endif}

{endif}

; as there is no AMS, these next three lines only serve to hide T[next_extruder]
; if this was not included, the T[next_extruder] command is input after this
; code and will cause the system to hang as the toolchange command searches
; for the AMS
M620 S[next_extruder]A
T[next_extruder]
M621 S[next_extruder]A

Theories

1. I suspect this has something to do with the breaking change to allow multiple TPUs in Bambu Studio here: New "Not support printing 2 or more TPU filaments" error when combining multiple TPU since BambuStudio 2.0 bambulab/BambuStudio#6834

2. The gcode starts with {if toolchange_count > 1}, I suspect the toolchange_count variable might have been changed to accommodate the H2D with multiple toolheads.

The M400 is the command that is supposed to pause, and that command is being ignored.

Attempts to fix

1. I've updated to the latest code from github yet this returns an issue similar to Unknown syntax error {endif} #15

machine_end_gcode Parsing error at line 55: Not a variable name {if next_extruder < 255}

[spuder]

Here is a stock filament swap on P1S using Bambu Studio 2.1.x
The filament swap happens from lines 984 to 1189

Stock1.gcode.3mf.zip

plate_1.gcode.zip

[AJ-Owen]

I am seeing some slightly different behaviour with my A1M.

Generating the gcode file runs without error, but the first filament switch does not happen; all subsequent switches work as expected.

Inspecting the gcode files, the conditional toolchange_count > 1 does seem to be the culprit.
I've generated gcode files with the following change in place:

• A1_mini_0.4_mm_nozzle...AJ-Owen:Bambu_CustomGCode:A1_mini_0.4_mm_nozzle

and the missing first swap is present.

Once my printer is free I will test the new gcode and ensure it works as expected.

I don't own a P1 printer but the logic should still follow to make the same change.

I agree with your theory about the introduction of the H2D - I can imagine there being some logic around if toolchange_count == 1 -> use second extruder and if toolchange_count >= 1 -> use AMS

edit: This has been tested several times on an A1-mini. Working as expected