The over purge problem this is with a .4 nozzle and breakaway support filament.
The current solution is custom G-code:
Version History:
V1.0 – Original release
V1.1 – Added text instructions for adjusting purge values
All the code below already has the reduced purge settings, currently set to 0.20 for both nozzles.
-
To change the purge settings, adjust the multiplier value in the Machine Start G-code and the Change Filament G-code.
-
If needed you can adjust with values like 0.10 , 0.05 , 0.01
-
If you require more purge, increase the value. (Sample 0.30)
Click on the save current machine.
Give it a name (sample H2D Low Purge 0.4 nozzle) then click ok.
Next remove the factory Machine start G-code then add the new adjustable purge setting Machine start G-code.
;===== Machine: H2D - Adjustable Purge Settings - Start G-code ===============
;===== Date: 20250501 =====================
;===== 3DTECH - V1.1 =========
;To adjust the purging, change the multiplier value in 0.10 , 0.05 , 0.01 steps (The currently lower purge default level is 0.20)
;M1002 set_flag extrude_cali_flag=1
;M1002 set_flag g29_before_print_flag=1
;M1002 set_flag auto_cali_toolhead_offset_flag=1
;M1002 set_flag build_plate_detect_flag=1
M993 A0 B0 C0 ; nozzle cam detection not allowed.
M400
;M73 P99
;=====printer start sound ===================
M17
M400 S1
M1006 S1
M1006 A53 B9 L99 C53 D9 M99 E53 F9 N99
M1006 A56 B9 L99 C56 D9 M99 E56 F9 N99
M1006 A61 B9 L99 C61 D9 M99 E61 F9 N99
M1006 A53 B9 L99 C53 D9 M99 E53 F9 N99
M1006 A56 B9 L99 C56 D9 M99 E56 F9 N99
M1006 A61 B18 L99 C61 D18 M99 E61 F18 N99
M1006 W
;=====printer start sound ===================
;===== reset machine status =================
M204 S10000
M630 S0 P0
G90
M17 D ; reset motor current to default
M960 S5 P1 ; turn on logo lamp
G90
M220 S100 ;Reset Feedrate
M221 S100 ;Reset Flowrate
M73.2 R1.0 ;Reset left time magnitude
G29.1 Z{+0.0} ; clear z-trim value first
M983.1 M1
M901 D4
M481 S0 ; turn off cutter pos comp
;===== reset machine status =================
M620 M ;enable remap
;===== avoid end stop =================
G91
G380 S2 Z22 F1200
G380 S2 Z-12 F1200
G90
;===== avoid end stop =================
;==== set airduct mode ====
{if (overall_chamber_temperature >= 40)}
M145 P1 ; set airduct mode to heating mode for heating
M106 P2 S0 ; turn off auxiliary fan
M106 P3 S0 ; turn off chamber fan
{else}
M145 P0 ; set airduct mode to cooling mode for cooling
M106 P2 S178 ; turn on auxiliary fan for cooling
M106 P3 S127 ; turn on chamber fan for cooling
M140 S0 ; stop heatbed from heating
M1002 gcode_claim_action : 29
M191 S0 ; wait for chamber temp
M142 P1 R35 S40 U0.3 V0.5 ; set chamber autocooling
M106 P2 S0 ; turn off auxiliary fan
{endif}
;==== set airduct mode ====
;===== start to heat heatbed & hotend==========
M1002 set_filament_type:{filament_type[initial_no_support_extruder]}
M104 S140 A
M140 S[bed_temperature_initial_layer_single]
;===== set chamber temperature ==========
{if (overall_chamber_temperature >= 40)}
M145 P1 ; set airduct mode to heating mode
M141 S[overall_chamber_temperature] ; Let Chamber begin to heat
{endif}
;===== set chamber temperature ==========
;===== start to heat heatbead & hotend==========
;====== cog noise reduction=================
M982.2 S1 ; turn on cog noise reduction
;===== first homing start =====
M1002 gcode_claim_action : 13
G28 X T300
G150.1 F18000 ; wipe mouth to avoid filament stick to heatbed
G150.3 F18000
M400 P200
M972 S24 P0 T2000
{if curr_bed_type=="Textured PEI Plate"}
M972 S26 P0 C0
{elsif curr_bed_type=="High Temp Plate"}
M972 S36 P0 C0 X1
{endif}
M972 S35 P0 C0
G90
G1 X175 Y160 F30000
G28 Z P0 T250
;===== first homign end =====
M400
;M73 P99
;===== detection start =====
T1001
G383.4 ; left-extruder load status detection
M104 S{nozzle_temperature_initial_layer[initial_no_support_extruder]-80} A ; rise temp in advance
M1002 judge_flag build_plate_detect_flag
M622 S1
M972 S19 P0 C0 ; heatbed presence detection
M623
M972 S14 P0 ; nozzle type detection
;===== detection end =====
M400
;M73 P99
;===== prepare print temperature and material ==========
M400
M211 X0 Y0 Z0 ; turn off soft endstop
M975 S1 ; turn on input shaping
G29.2 S0 ; avoid invalid abl data
;===== Custom reduced purge settings =====
M620.10 A0 F{filament_max_volumetric_speed[initial_no_support_extruder]/2.4053*60} H{nozzle_diameter[initial_no_support_extruder]} T{nozzle_temperature_range_high[initial_no_support_extruder]} P{nozzle_temperature_initial_layer[initial_no_support_extruder]} S1 E-{retraction_distances_when_cut[initial_no_support_extruder]}*0.20 ;To adjust the purging, change the multiplier value in 0.10 , 0.05 , 0.01 steps (The currently lower purge default level is 0.20)
M620.10 A1 F{filament_max_volumetric_speed[initial_no_support_extruder]/2.4053*60} H{nozzle_diameter[initial_no_support_extruder]} T{nozzle_temperature_range_high[initial_no_support_extruder]} P{nozzle_temperature_initial_layer[initial_no_support_extruder]} S1 E-{retraction_distances_when_cut[initial_no_support_extruder]}*0.20 ;To adjust the purging, change the multiplier value in 0.10 , 0.05 , 0.01 steps (The currently lower purge default level is 0.20)
;===================================
; Other filament-specific settings (TPU, PA, PA-GF)
{if filament_type[initial_no_support_extruder] == "TPU"}
M620.11 S0 L0 I[initial_no_support_extruder] E-{retraction_distances_when_cut[initial_no_support_extruder]} F{filament_max_volumetric_speed[initial_no_support_extruder]/2.4053*60}
{else}
{if (filament_type[initial_no_support_extruder] == "PA") || (filament_type[initial_no_support_extruder] == "PA-GF")}
M620.11 S1 L0 I[initial_no_support_extruder] R4 D2 E-{retraction_distances_when_cut[initial_no_support_extruder]} F{filament_max_volumetric_speed[initial_no_support_extruder]/2.4053*60}
{else}
M620.11 S1 L0 I[initial_no_support_extruder] R10 D8 E-{retraction_distances_when_cut[initial_no_support_extruder]} F{filament_max_volumetric_speed[initial_no_support_extruder]/2.4053*60}
{endif}
{endif}
;=======================================================================================================================
M620 S[initial_no_support_extruder]A ; switch material if AMS exist
M1002 gcode_claim_action : 4
M1002 set_filament_type:UNKNOWN
M400
T[initial_no_support_extruder]
M400
M628 S0
M629
M400
M1002 set_filament_type:{filament_type[initial_no_support_extruder]}
M621 S[initial_no_support_extruder]A
M104 S{nozzle_temperature_initial_layer[initial_no_support_extruder]}
M400
M106 P1 S0
G29.2 S1
;===== prepare print temperature and material ==========
M400
;M73 P99
;===== auto extrude cali start =========================
M975 S1
M1002 judge_flag extrude_cali_flag
M622 J0
M983.3 F{filament_max_volumetric_speed[initial_no_support_extruder]/2.4} A0.4 ; cali dynamic extrusion compensation
M623
M622 J1
M1002 set_filament_type:{filament_type[initial_no_support_extruder]}
M1002 gcode_claim_action : 8
M109 S{nozzle_temperature[initial_no_support_extruder]}
G90
M83
M983.3 F{filament_max_volumetric_speed[initial_no_support_extruder]/2.4} A0.4 ; cali dynamic extrusion compensation
M400
M106 P1 S255
M400 S5
M106 P1 S0
G150.3
M623
M622 J2
M1002 set_filament_type:{filament_type[initial_no_support_extruder]}
M1002 gcode_claim_action : 8
M109 S{nozzle_temperature[initial_no_support_extruder]}
G90
M83
M983.3 F{filament_max_volumetric_speed[initial_no_support_extruder]/2.4} A0.4 ; cali dynamic extrusion compensation
M400
M106 P1 S255
M400 S5
M106 P1 S0
G150.3
M623
;===== auto extrude cali end =========================
{if filament_type[initial_no_support_extruder] == "TPU"}
G150.2
G150.1
G150.2
G150.1
G150.2
G150.1
{else}
M106 P1 S0
M400 S2
M83
G1 E45 F{filament_max_volumetric_speed[initial_no_support_extruder]/2.4053*60}
G1 E-3 F1800
M400 P500
G150.2
G150.1
{endif}
G91
G1 Y-16 F12000 ; move away from the trash bin
G90
M400
;M73 P99
;===== wipe right nozzle start =====
M1002 gcode_claim_action : 14
G150 T{nozzle_temperature_initial_layer[initial_no_support_extruder]}
{if (overall_chamber_temperature >= 40)}
G150 T{nozzle_temperature_initial_layer[initial_no_support_extruder] - 80}
{endif}
M106 S255 ; turn on fan to cool the nozzle
;===== wipe left nozzle end =====
M400
;M73 P99
{if (overall_chamber_temperature >= 40)}
M1002 gcode_claim_action : 49
M191 S[overall_chamber_temperature] ; wait for chamber temp
{endif}
M400
;M73 P99
;===== bed leveling ==================================
M1002 judge_flag g29_before_print_flag
M190 S[bed_temperature_initial_layer_single]; ensure bed temp
M109 S140 A
M106 S0 ; turn off fan , too noisy
G91
G1 Z5 F1200
G90
G1 X275 Y300 F30000
M622 J1
M1002 gcode_claim_action : 1
G29.20 A3
G29 A1 O X{first_layer_print_min[0]} Y{first_layer_print_min[1]} I{first_layer_print_size[0]} J{first_layer_print_size[1]}
M400
M500 ; save cali data
M623
M622 J2
M1002 gcode_claim_action : 1
{if has_tpu_in_first_layer}
G29.20 A3
G29 A1 O X{first_layer_print_min[0]} Y{first_layer_print_min[1]} I{first_layer_print_size[0]} J{first_layer_print_size[1]}
{else}
G29.20 A4
G29 A2 O X{first_layer_print_min[0]} Y{first_layer_print_min[1]} I{first_layer_print_size[0]} J{first_layer_print_size[1]}
{endif}
M400
M500 ; save cali data
M623
M622 J0
G28
M623
;===== bed leveling end ================================
G39.1 ; cali nozzle wrapped detection pos
M500
;===== z ofst cali start =====
M190 S[bed_temperature_initial_layer_single]; ensure bed temp
G383 O0 M2 T140
M500
;===== z ofst cali end =====
M400
;M73 P99
M141 S[overall_chamber_temperature]
M104 S{nozzle_temperature_initial_layer[initial_no_support_extruder]} A
;===== mech mode sweep start =====
M1002 gcode_claim_action : 3
G90
G1 Z5 F1200
G1 X187 Y160 F20000
T1000
M400 P200
M970.3 Q1 A5 K0 O1
M974 Q1 S2 P0
M970.3 Q0 A5 K0 O1
M974 Q0 S2 P0
M970.2 Q2 K0 W38 Z0.01
M974 Q2 S2 P0
M500
M975 S1
;===== mech mode sweep end =====
M400
;M73 P99
G150.3 ; move to garbage can to wait for temp
M1026
;===== xy ofst cali start =====
M1002 judge_flag auto_cali_toolhead_offset_flag
M622 J0
M1012.5 N1 R1
M623
M622 J1
M1002 gcode_claim_action : 39
M141 S0
M620.17 T0 S{nozzle_temperature_initial_layer[(first_non_support_filaments[0] != -1 ? first_non_support_filaments[0] : first_filaments[0])]} L{(first_non_support_filaments[0] != -1 ? first_non_support_filaments[0] : first_filaments[0])}
M620.17 T1 S{nozzle_temperature_initial_layer[(first_non_support_filaments[1] != -1 ? first_non_support_filaments[1] : first_filaments[1])]} L{(first_non_support_filaments[1] != -1 ? first_non_support_filaments[1] : first_filaments[1])}
G383 O1 T{nozzle_temperature_initial_layer[initial_no_support_extruder]} L{initial_no_support_extruder}
M500
M141 S[overall_chamber_temperature]
M623
M622 J2
M1002 gcode_claim_action : 39
M141 S0
M620.17 T0 S{nozzle_temperature_initial_layer[(first_non_support_filaments[0] != -1 ? first_non_support_filaments[0] : first_filaments[0])]} L{(first_non_support_filaments[0] != -1 ? first_non_support_filaments[0] : first_filaments[0])}
M620.17 T1 S{nozzle_temperature_initial_layer[(first_non_support_filaments[1] != -1 ? first_non_support_filaments[1] : first_filaments[1])]} L{(first_non_support_filaments[1] != -1 ? first_non_support_filaments[1] : first_filaments[1])}
G383.3 T{nozzle_temperature_initial_layer[initial_no_support_extruder]} L{initial_no_support_extruder}
M500
M141 S[overall_chamber_temperature]
M623
;===== xy ofst cali end =====
M400
;M73 P99
M1002 gcode_claim_action : 0
M400
;============switch again==================
M211 X0 Y0 Z0 ;turn off soft endstop
G91
G1 Z6 F1200
G90
M1002 set_filament_type:{filament_type[initial_no_support_extruder]}
M620 S[initial_no_support_extruder]A
M400
T[initial_no_support_extruder]
M400
M628 S0
M629
M400
M621 S[initial_no_support_extruder]A
;============switch again==================
M400
;M73 P99
;===== wait temperature reaching the reference value =======
M104 S{nozzle_temperature_initial_layer[initial_no_support_extruder]} ; rise to print tmpr
M140 S[bed_temperature_initial_layer_single]
M190 S[bed_temperature_initial_layer_single]
;========turn off light and fans =============
M960 S1 P0 ; turn off laser
M960 S2 P0 ; turn off laser
M106 S0 ; turn off fan
M106 P2 S0 ; turn off big fan
{if (overall_chamber_temperature >= 40)}
M106 P3 S0 ; turn off chamber fan
{else}
M142 P1 R35 S40 U0.3 V0.5 ; set chamber autocooling
{endif}
;============set motor current==================
M400 S1
;===== wait temperature reaching the reference value =======
M400
;M73 P99
;===== for Textured PEI Plate , lower the nozzle as the nozzle was touching topmost of the texture when homing ==
{if curr_bed_type=="Textured PEI Plate"}
G29.1 Z{-0.02} ; for Textured PEI Plate
{endif}
G150.1
M975 S1 ; turn on mech mode supression
M983.4 S1 ; turn on deformation compensation
G29.2 S1 ; turn on pos comp
G29.7 S1
G90
G1 Z5 F1200
G1 Y295 F30000
G1 Y265 F18000
;===== nozzle load line ===============================
G29.2 S1 ; ensure z comp turn on
G90
M83
M109 S{nozzle_temperature_initial_layer[initial_no_support_extruder]}
{if filament_type[initial_no_support_extruder] == "TPU"}
;G130 O0 F{filament_max_volumetric_speed[initial_no_support_extruder]/2/2.4053} L80 E5 D12 A{first_layer_print_min[0]} B{first_layer_print_min[1]} I{first_layer_print_size[0]} J{first_layer_print_size[1]}
G130 O0 X250 Y-0.5 Z0.8 F{filament_max_volumetric_speed[initial_no_support_extruder]/2/2.4053} L40 E20 D5
{else}
;G130 O0 F{filament_max_volumetric_speed[initial_no_support_extruder]/2/2.4053} L80 E5 D12 A{first_layer_print_min[0]} B{first_layer_print_min[1]} I{first_layer_print_size[0]} J{first_layer_print_size[1]}
G130 O0 X250 Y-0.5 Z0.8 F{filament_max_volumetric_speed[initial_no_support_extruder]/2/2.4053} L40 E20 D5
{endif}
G90
M83
G1 Z0.2
;===== noozle load line end ===========================
M400
;M73 P99
M993 A1 B1 C1 ; nozzle cam detection allowed.
{if (filament_type[initial_no_support_extruder] == "TPU")}
M1015.3 S1;enable tpu clog detect
{else}
M1015.3 S0;disable tpu clog detect
{endif}
{if (filament_type[initial_no_support_extruder] == "PLA") || (filament_type[initial_no_support_extruder] == "PETG")
|| (filament_type[initial_no_support_extruder] == "PLA-CF") || (filament_type[initial_no_support_extruder] == "PETG-CF")}
M1015.4 S1 K1 H[nozzle_diameter] ;enable E air printing detect
{else}
M1015.4 S0 K0 H[nozzle_diameter] ;disable E air printing detect
{endif}
M620.6 I[initial_no_support_extruder] W1 ;enable ams air printing detect
M211 Z1
G29.99
Next remove the factory change filament G-code then add the new adjustable purge setting change filament G-code.
;===== Machine: H2D - Adjustable Purge Settings - Change Filament G-code ===============
;===== Date: 20250501 =====================
;===== 3DTECH - V1.1 =========
;To adjust the purging, change the multiplier value in 0.10 , 0.05 , 0.01 steps (The currently lower purge default level is 0.20)
M993 A2 B2 C2 ; nozzle cam detection allow status save.
M993 A0 B0 C0 ; nozzle cam detection not allowed.
{if (filament_type[next_extruder] == "PLA") || (filament_type[next_extruder] == "PETG")
|| (filament_type[next_extruder] == "PLA-CF") || (filament_type[next_extruder] == "PETG-CF")}
M1015.4 S1 K0 ;disable E air printing detect
{else}
M1015.4 S0 ; disable E air printing detect
{endif}
M620 S[next_extruder]A
M1002 gcode_claim_action : 4
M204 S9000
G1 Z{max_layer_z + 3.0} F1200
M400
M106 P1 S0
M106 P2 S0
{if toolchange_count == 2}
; get travel path for change filament
;M620.1 X[travel_point_1_x] Y[travel_point_1_y] F21000 P0
;M620.1 X[travel_point_2_x] Y[travel_point_2_y] F21000 P1
;M620.1 X[travel_point_3_x] Y[travel_point_3_y] F21000 P2
{endif}
;===== Custom Reduced Purge Settings =====
M620.10 A0 F{filament_max_volumetric_speed[initial_no_support_extruder]/2.4053*60} H{nozzle_diameter[initial_no_support_extruder]} T{nozzle_temperature_range_high[initial_no_support_extruder]} P{nozzle_temperature_initial_layer[initial_no_support_extruder]} S1 E-{retraction_distances_when_cut[initial_no_support_extruder]}*0.20 ;To adjust the purging, change the multiplier value in 0.10 , 0.05 , 0.01 steps (The currently lower purge default level is 0.20)
M620.10 A1 F{filament_max_volumetric_speed[initial_no_support_extruder]/2.4053*60} H{nozzle_diameter[initial_no_support_extruder]} T{nozzle_temperature_range_high[initial_no_support_extruder]} P{nozzle_temperature_initial_layer[initial_no_support_extruder]} S1 E-{retraction_distances_when_cut[initial_no_support_extruder]}*0.20 ;To adjust the purging, change the multiplier value in 0.10 , 0.05 , 0.01 steps (The currently lower purge default level is 0.20)
;====================================
{if filament_type[current_extruder] == "TPU"}
M620.11 S0 L0 I[current_extruder] E-{retraction_distances_when_cut[current_extruder]} F{max((filament_max_volumetric_speed[current_extruder]/2.4053*60), 200)}
{else}
{if (filament_type[current_extruder] == "PA") || (filament_type[current_extruder] == "PA-GF")}
M620.11 S1 L0 I[current_extruder] R4 D2 E-{retraction_distances_when_cut[current_extruder]} F{max((filament_max_volumetric_speed[current_extruder]/2.4053*60), 200)}
{else}
M620.11 S1 L0 I[current_extruder] R10 D8 E-{retraction_distances_when_cut[current_extruder]} F{max((filament_max_volumetric_speed[current_extruder]/2.4053*60), 200)}
{endif}
{endif}
{if filament_type[current_extruder] == "TPU" || filament_type[next_extruder] == "TPU"}
M620.11 H2 C331
{else}
M620.11 H0
{endif}
T[next_extruder]
;deretract
{if filament_type[next_extruder] == "TPU"}
{else}
{if (filament_type[next_extruder] == "PA") || (filament_type[next_extruder] == "PA-GF")}
;VG1 E1 F{max(new_filament_e_feedrate, 200)}
;VG1 E1 F{max(new_filament_e_feedrate/2, 100)}
{else}
;VG1 E4 F{max(new_filament_e_feedrate, 200)}
;VG1 E4 F{max(new_filament_e_feedrate/2, 100)}
{endif}
{endif}
; VFLUSH_START
{if flush_length>41.5}
;VG1 E41.5 F{min(old_filament_e_feedrate,new_filament_e_feedrate)}
;VG1 E{flush_length-41.5} F{new_filament_e_feedrate}
{else}
;VG1 E{flush_length} F{min(old_filament_e_feedrate,new_filament_e_feedrate)}
{endif}
SYNC T{ceil(flush_length / 125) * 5}
; VFLUSH_END
M1002 set_filament_type:{filament_type[next_extruder]}
M400
M83
{if next_extruder < 255}
M628 S0
;VM109 S[new_filament_temp]
M629
M400
M983.3 F{filament_max_volumetric_speed[next_extruder]/2.4} A0.4
M400
{if wipe_avoid_perimeter}
G1 Y320 F30000
G1 X{wipe_avoid_pos_x} F30000
{endif}
G1 Y295 F30000
G1 Y265 F18000
G1 Z{max_layer_z + 3.0} 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}
M621 S[next_extruder]A
M993 A3 B3 C3 ; nozzle cam detection allow status restore.
{if (filament_type[next_extruder] == "TPU")}
M1015.3 S1;enable tpu clog detect
{else}
M1015.3 S0;disable tpu clog detect
{endif}
{if (filament_type[next_extruder] == "PLA") || (filament_type[next_extruder] == "PETG")
|| (filament_type[next_extruder] == "PLA-CF") || (filament_type[next_extruder] == "PETG-CF")}
M1015.4 S1 K1 H[nozzle_diameter] ;enable E air printing detect
{else}
M1015.4 S0 ; disable E air printing detect
{endif}
M620.6 I[next_extruder] W1 ;enable ams air printing detect
M1002 gcode_claim_action : 0
This G-code has not been tested with all combinations of filament types and nozzle sizes, so some fine-tuning may be necessary.
This issue prompted me to release version 1.0 ahead of schedule. With your input and feedback on the community forum, we can all work together to fine-tune the settings or develop custom purge routines tailored to various filament types and nozzle sizes.
Notes: I’ve also been using smaller values for the support filament interface layers when a prime tower is needed.
