Bambu G-code Reference

This document contains a table of all the G-codes and M-codes that Bambu Studio (Marlin/Legacy mode) generates, including Bambu-specific codes. Each entry includes the code and a brief description of its purpose. This is very much a work in progress and is being done for the purpose of learning how to better understand the machine code generated by Bambu Studio.

Why I created this reference document

I started this repo because I couldn't locate a reliable enough source for this documentation and it appears Bambu Lab has no interest in creating such documentation. The Bambu Lab Community Forum is the next most reliable source of information when it comes to reading, writing, and learning to modify gcode for Bambu Lab machines. Any relevant posts are linked in the References. If you have knowledge to contribute to this repo, submit a pull request.

Table of Contents

• Header Comments
  • What are header comments and what are they used for?
  • Observations
  • List of Comments
• Standard Marlin G-codes
• Standard Marlin M-codes
• Bambu-Specific G-codes
• Bambu-Specific M-codes
• References

---

Header Comments

The metadata found in the top 400+ lines of any file generated by Bambu Studio consists of values used by Bambu Studio and ignored by the printer during execution. Each line begins with a semicolon ; to indicate it's a comment in gcode.

What are header comments and what are they used for?

• They are not parsed by Marlin firmware or used in motion/temperature control.
• The actual print moves and temperatures are controlled only by G/M-codes.
• The printer ignores all comments during runtime execution.
• Bambu Studio uses the header comments. How each comment is used is still TBD.

Observations

1. If you remove the header and config blocks form the gcode file, Bambu Studio will crash.
2. If you include the header block only, you get an error and the toolpath doesn't load. The app does not crash.
3. Any of the comments in the header that start with ; printer_ have something to do with how the file is rendered in Bambu studio.
4. If you remove the data from the following lines, the code still opens in Bambu studio.
   • ; machine_start_gcode =
   • ; machine_end_gcode =
   • ; layer_change_gcode =
   • ; time_lapse_gcode =
   • ; change_filament_gcode =

List of Comments

Line	Comment	Value	Type	Purpose
1	; HEADER_BLOCK_START			Header block start
2	; BambuStudio	02.00.01.50		Version of Bambu Studio that generated this file
3	; model printing time	21s		How long it takes to print
4	; total estimated time	6m 39s		Total estimated job time
5	; total layer number	3	int	Number of layers
6	; total filament length [mm]	35.16	float	Total filament used
7	; total filament volume [cm^3]	84.58	float	Total filament volume
8	; total filament weight [g]	0.11	float	Total filament weight
9	; filament_density	1.26	float	Filament density
10	; filament_diameter	1.75	float	Filament diameter
11	; max_z_height	0.6	float	Maximum layer height of job
12	; HEADER_BLOCK_END			Header block end
14	; CONFIG_BLOCK_START			Config block start
15	; accel_to_decel_enable	0	int
16	; accel_to_decel_factor	50%
17	; activate_air_filtration	0	int
18	; additional_cooling_fan_speed	70	int
19	; apply_scarf_seam_on_circles	1	int
20	; auxiliary_fan	1	int
21	; bed_custom_model
22	; bed_custom_texture
23	; bed_exclude_area	0x0,18x0,18x28,0x28
24	; bed_temperature_formula	by_first_filament
25	; before_layer_change_gcode
26	; best_object_pos	0.5,0.5
27	; bottom_color_penetration_layers	3	int
28	; bottom_shell_layers	0	int
29	; bottom_shell_thickness	0	int
30	; bottom_surface_pattern	monotonic
31	; bridge_angle	0	int
32	; bridge_flow	1	int
33	; bridge_no_support	0	int
34	; bridge_speed	50	int
35	; brim_object_gap	0.1	float
36	; brim_type	auto_brim
37	; brim_width	5	int
38	; chamber_temperatures	0	int
39	; change_filament_gcode
40	; circle_compensation_manual_offset	0	int
41	; circle_compensation_speed	200	int
42	; close_fan_the_first_x_layers	1	int
43	; complete_print_exhaust_fan_speed	70	int
44	; cool_plate_temp	35	int
45	; cool_plate_temp_initial_layer	35	int
46	; counter_coef_1	0	int
47	; counter_coef_2	0.008	float
48	; counter_coef_3	-0.041	float
49	; counter_limit_max	0.033	float
50	; counter_limit_min	-0.035	float
51	; curr_bed_type	Textured PEI Plate
52	; default_acceleration	10000	int
53	; default_filament_colour	""
54	; default_filament_profile	"Bambu PLA Basic @BBL X1C"
55	; default_jerk	0	int
56	; default_nozzle_volume_type	Standard
57	; default_print_profile	0.20mm Standard @BBL X1C
58	; deretraction_speed	30	int
59	; detect_floating_vertical_shell	1	int
60	; detect_narrow_internal_solid_infill	1	int
61	; detect_overhang_wall	1	int
62	; detect_thin_wall	0	int
63	; diameter_limit	50	int
64	; different_settings_to_system
65	; draft_shield	disabled
66	; during_print_exhaust_fan_speed	70	int
67	; elefant_foot_compensation	0	int
68	; enable_arc_fitting	1	int
69	; enable_circle_compensation	0	int
70	; enable_long_retraction_when_cut	2	int
71	; enable_overhang_bridge_fan	1	int
72	; enable_overhang_speed	1	int
73	; enable_pre_heating	0	int
74	; enable_pressure_advance	0	int
75	; enable_prime_tower	0	int
76	; enable_support	0	int
77	; enforce_support_layers	0	int
78	; eng_plate_temp	0	int
79	; eng_plate_temp_initial_layer	0	int
80	; ensure_vertical_shell_thickness	enabled
81	; exclude_object	1	int
82	; extruder_ams_count	1#0|4#0;
83	; extruder_clearance_dist_to_rod	33	int
84	; extruder_clearance_height_to_lid	90	int
85	; extruder_clearance_height_to_rod	34	int
86	; extruder_clearance_max_radius	68	int
87	; extruder_colour	#018001
88	; extruder_offset	0x2
89	; extruder_printable_area
90	; extruder_type	Direct Drive
91	; extruder_variant_list	"Direct Drive Standard"
92	; fan_cooling_layer_time	100	int
93	; fan_max_speed	100	int
94	; fan_min_speed	100	int
95	; filament_adhesiveness_category	100	int
96	; filament_change_length	5	int
97	; filament_colour	#00AE42
98	; filament_cost	24.99	float
99	; filament_density	1.26	float
100	; filament_diameter	1.75	float
101	; filament_end_gcode	"; filament end gcode \n\n"
102	; filament_extruder_variant	"Direct Drive Standard"
103	; filament_flow_ratio	0.98	float
104	; filament_ids	GFA00
105	; filament_is_support	0	int
106	; filament_long_retractions_when_cut	1	int
107	; filament_map	1	int
108	; filament_map_mode	Auto For Flush
109	; filament_max_volumetric_speed	21	int
110	; filament_minimal_purge_on_wipe_tower	15	int
111	; filament_notes
112	; filament_pre_cooling_temperature	0	int
113	; filament_prime_volume	30	int
114	; filament_ramming_travel_time	0	int
115	; filament_ramming_volumetric_speed	-1	int
116	; filament_retraction_distances_when_cut	18	int
117	; filament_scarf_gap	0	int
118	; filament_scarf_height	0.1	float
119	; filament_scarf_length	10	int
120	; filament_scarf_seam_type	none
121	; filament_self_index	1	int
122	; filament_settings_id	"Bambu PLA Basic @BBL X1C"
123	; filament_shrink	1	int
124	; filament_soluble	0	int
125	; filament_start_gcode
126	; filament_type	PLA
127	; filament_vendor	"Bambu Lab"
128	; filename_format	{input_filename_base}{filament_type[0]}{print_time}.gcode
129	; filter_out_gap_fill	0	int
130	; first_layer_print_sequence	0	int
131	; flush_into_infill	0	int
132	; flush_into_objects	0	int
133	; flush_into_support	1	int
134	; flush_multiplier	1	int
135	; flush_volumes_matrix	0	int
136	; flush_volumes_vector	140,140
137	; full_fan_speed_layer	0	int
138	; fuzzy_skin	none
139	; fuzzy_skin_point_distance	0.8	float
140	; fuzzy_skin_thickness	0.3	float
141	; gap_infill_speed	250	int
142	; gcode_add_line_number	0	int
143	; gcode_flavor	marlin
144	; grab_length	0	int
145	; has_scarf_joint_seam	1	int
146	; head_wrap_detect_zone
147	; hole_coef_1	0	int
148	; hole_coef_2	-0.008	float
149	; hole_coef_3	0.23415	float
150	; hole_limit_max	0.22	float
151	; hole_limit_min	0.088	float
152	; host_type	octoprint
153	; hot_plate_temp	55	int
154	; hot_plate_temp_initial_layer	55	int
155	; hotend_cooling_rate	2	int
156	; hotend_heating_rate	2	int
157	; impact_strength_z	13.8	float
158	; independent_support_layer_height	1	int
159	; infill_combination	0	int
160	; infill_direction	45	int
161	; infill_jerk	9	int
162	; infill_rotate_step	0	int
163	; infill_shift_step	0.4	float
164	; infill_wall_overlap	0.15	float
165	; initial_layer_acceleration	500	int
166	; initial_layer_flow_ratio	1	int
167	; initial_layer_infill_speed	105	int
168	; initial_layer_jerk	9	int
169	; initial_layer_line_width	0.5	float
170	; initial_layer_print_height	0.2	float
171	; initial_layer_speed	50	int
172	; initial_layer_travel_acceleration	6000	int
173	; inner_wall_acceleration	0	int
174	; inner_wall_jerk	9	int
175	; inner_wall_line_width	0.45	float
176	; inner_wall_speed	300	int
177	; interface_shells	0	int
178	; interlocking_beam	0	int
179	; interlocking_beam_layer_count	2	int
180	; interlocking_beam_width	0.8	float
181	; interlocking_boundary_avoidance	2	int
182	; interlocking_depth	2	int
183	; interlocking_orientation	22.5	float
184	; internal_bridge_support_thickness	0.8	float
185	; internal_solid_infill_line_width	0.42	float
186	; internal_solid_infill_pattern	zig-zag
187	; internal_solid_infill_speed	250	int
188	; ironing_direction	45	int
189	; ironing_flow	0.1	float
190	; ironing_inset	0.21	float
191	; ironing_pattern	zig-zag
192	; ironing_spacing	0.15	float
193	; ironing_speed	30	int
194	; ironing_type	no ironing
195	; is_infill_first	0	int
196	; layer_change_gcode
197	; layer_height	0.2	float
198	; line_width	0.42	float
199	; long_retractions_when_cut	0	int
200	; machine_end_gcode
201	; machine_load_filament_time	29	int
202	; machine_max_acceleration_e	5000,5000
203	; machine_max_acceleration_extruding	20000,20000
204	; machine_max_acceleration_retracting	5000,5000
205	; machine_max_acceleration_travel	9000,9000
206	; machine_max_acceleration_x	20000,20000
207	; machine_max_acceleration_y	20000,20000
208	; machine_max_acceleration_z	500,200
209	; machine_max_jerk_e	2.5,2.5
210	; machine_max_jerk_x	9,9
211	; machine_max_jerk_y	9,9
212	; machine_max_jerk_z	3,3
213	; machine_max_speed_e	30,30
214	; machine_max_speed_x	500,200
215	; machine_max_speed_y	500,200
216	; machine_max_speed_z	20,20
217	; machine_min_extruding_rate	0,0
218	; machine_min_travel_rate	0,0
219	; machine_pause_gcode	M400 U1
220	; machine_start_gcode
221	; machine_switch_extruder_time	0	int
222	; machine_unload_filament_time	28	int
223	; master_extruder_id	1	int
224	; max_bridge_length	0	int
225	; max_layer_height	0.28	float
226	; max_travel_detour_distance	0	int
227	; min_bead_width	0.85	float
228	; min_feature_size	0.25	float
229	; min_layer_height	0.08	float
230	; minimum_sparse_infill_area	15	int
231	; mmu_segmented_region_interlocking_depth	0	int
232	; mmu_segmented_region_max_width	0	int
233	; nozzle_diameter	0.4	float
234	; nozzle_height	4.2	float
235	; nozzle_temperature	220	int
236	; nozzle_temperature_initial_layer	220	int
237	; nozzle_temperature_range_high	240	int
238	; nozzle_temperature_range_low	190	int
239	; nozzle_type	stainless_steel
240	; nozzle_volume	107	int
241	; nozzle_volume_type	Standard
242	; only_one_wall_first_layer	0	int
243	; ooze_prevention	0	int
244	; other_layers_print_sequence	0	int
245	; other_layers_print_sequence_nums	0	int
246	; outer_wall_acceleration	5000	int
247	; outer_wall_jerk	9	int
248	; outer_wall_line_width	0.42	float
249	; outer_wall_speed	200	int
250	; overhang_1_4_speed	0	int
251	; overhang_2_4_speed	50	int
252	; overhang_3_4_speed	30	int
253	; overhang_4_4_speed	10	int
254	; overhang_fan_speed	100	int
255	; overhang_fan_threshold	0.5	float
256	; overhang_threshold_participating_cooling	0.95	float
257	; overhang_totally_speed	10	int
258	; physical_extruder_map	0	int
259	; post_process
260	; pre_start_fan_time	2	int
261	; precise_z_height	0	int
262	; pressure_advance	0.02	float
263	; prime_tower_brim_width	3	int
264	; prime_tower_enable_framework	0	int
265	; prime_tower_extra_rib_length	0	int
266	; prime_tower_fillet_wall	1	int
267	; prime_tower_infill_gap	1.5	float
268	; prime_tower_lift_height	-1	int
269	; prime_tower_lift_speed	90	int
270	; prime_tower_max_speed	90	int
271	; prime_tower_rib_wall	1	int
272	; prime_tower_rib_width	8	int
273	; prime_tower_skip_points	1	int
274	; prime_tower_width	35	int
275	; print_compatible_printers
276	; print_extruder_id	1	int
277	; print_extruder_variant	"Direct Drive Standard"
278	; print_flow_ratio	1	int
279	; print_sequence	by layer
280	; print_settings_id	0.20mm Standard @BBL X1C
281	; printable_area	0x0,256x0,256x256,0x256
282	; printable_height	250	int
283	; printer_extruder_id	1	int
284	; printer_extruder_variant	"Direct Drive Standard"
285	; printer_model	Bambu Lab P1S
286	; printer_notes
287	; printer_settings_id	Bambu Lab P1S 0.4 nozzle
288	; printer_structure	corexy
289	; printer_technology	FFF
290	; printer_variant	0.4	float
291	; printhost_authorization_type	key
292	; printhost_ssl_ignore_revoke	0	int
293	; printing_by_object_gcode
294	; process_notes
295	; raft_contact_distance	0.1	float
296	; raft_expansion	1.5	float
297	; raft_first_layer_density	0.9	float
298	; raft_first_layer_expansion	2	int
299	; raft_layers	0	int
300	; reduce_crossing_wall	0	int
301	; reduce_fan_stop_start_freq	1	int
302	; reduce_infill_retraction	1	int
303	; required_nozzle_HRC	3	int
304	; resolution	0.012	float
305	; retract_before_wipe	0	int
306	; retract_length_toolchange	2	int
307	; retract_lift_above	0	int
308	; retract_lift_below	249	int
309	; retract_restart_extra	0	int
310	; retract_restart_extra_toolchange	0	int
311	; retract_when_changing_layer	1	int
312	; retraction_distances_when_cut	18	int
313	; retraction_length	0.8	float
314	; retraction_minimum_travel	1	int
315	; retraction_speed	30	int
316	; role_base_wipe_speed	1	int
317	; scan_first_layer	0	int
318	; scarf_angle_threshold	155	int
319	; seam_gap	0.15	float
320	; seam_position	aligned
321	; seam_slope_conditional	1	int
322	; seam_slope_entire_loop	0	int
323	; seam_slope_inner_walls	1	int
324	; seam_slope_steps	10	int
325	; silent_mode	0	int
326	; single_extruder_multi_material	1	int
327	; skirt_distance	2	int
328	; skirt_height	1	int
329	; skirt_loops	0	int
330	; slice_closing_radius	0.049	float
331	; slicing_mode	regular
332	; slow_down_for_layer_cooling	1	int
333	; slow_down_layer_time	4	int
334	; slow_down_min_speed	20	int
335	; small_perimeter_speed	0.5	float
336	; small_perimeter_threshold	0	int
337	; smooth_coefficient	150	int
338	; smooth_speed_discontinuity_area	1	int
339	; solid_infill_filament	1	int
340	; sparse_infill_acceleration	1	int
341	; sparse_infill_anchor	4	int
342	; sparse_infill_anchor_max	20	int
343	; sparse_infill_density	0	int
344	; sparse_infill_filament	1	int
345	; sparse_infill_line_width	0.45	float
346	; sparse_infill_pattern	grid
347	; sparse_infill_speed	270	int
348	; spiral_mode	0	int
349	; spiral_mode_max_xy_smoothing	2	int
350	; spiral_mode_smooth	0	int
351	; standby_temperature_delta	-5	int
352	; start_end_points	30x-3,54x245
353	; supertack_plate_temp	45	int
354	; supertack_plate_temp_initial_layer	45	int
355	; support_air_filtration	0	int
356	; support_angle	0	int
357	; support_base_pattern	default
358	; support_base_pattern_spacing	2.5	float
359	; support_bottom_interface_spacing	0.5	float
360	; support_bottom_z_distance	0.2	float
361	; support_chamber_temp_control	0	int
362	; support_critical_regions_only	0	int
363	; support_expansion	0	int
364	; support_filament	0	int
365	; support_interface_bottom_layers	2	int
366	; support_interface_filament	0	int
367	; support_interface_loop_pattern	0	int
368	; support_interface_not_for_body	1	int
369	; support_interface_pattern	auto
370	; support_interface_spacing	0.5	float
371	; support_interface_speed	80	int
372	; support_interface_top_layers	2	int
373	; support_line_width	0.42	float
374	; support_object_first_layer_gap	0.2	float
375	; support_object_xy_distance	0.35	float
376	; support_on_build_plate_only	0	int
377	; support_remove_small_overhang	1	int
378	; support_speed	150	int
379	; support_style	default
380	; support_threshold_angle	30	int
381	; support_top_z_distance	0.2	float
382	; support_type	tree(auto)
383	; symmetric_infill_y_axis	0	int
384	; temperature_vitrification	45	int
385	; template_custom_gcode
386	; textured_plate_temp	55	int
387	; textured_plate_temp_initial_layer	55	int
388	; thick_bridges	0	int
389	; thumbnail_size	50x50
390	; time_lapse_gcode
391	; timelapse_type	0	int
392	; top_area_threshold	2	int
393	; top_color_penetration_layers	5	int
394	; top_one_wall_type	all top
395	; top_shell_layers	0	int
396	; top_shell_thickness	1	int
397	; top_solid_infill_flow_ratio	1	int
398	; top_surface_acceleration	2000	int
399	; top_surface_jerk	9	int
400	; top_surface_line_width	0.42	float
401	; top_surface_pattern	monotonicline
402	; top_surface_speed	200	int
403	; travel_acceleration	10000	int
404	; travel_jerk	9	int
405	; travel_speed	500	int
406	; travel_speed_z	0	int
407	; tree_support_branch_angle	45	int
408	; tree_support_branch_diameter	2	int
409	; tree_support_branch_diameter_angle	5	int
410	; tree_support_branch_distance	5	int
411	; tree_support_wall_count	0	int
412	; unprintable_filament_types	""
413	; upward_compatible_machine
414	; use_firmware_retraction	0	int
415	; use_relative_e_distances	1	int
416	; vertical_shell_speed	0.8	float
417	; wall_distribution_count	1	int
418	; wall_filament	1	int
419	; wall_generator	classic
420	; wall_loops	1	int
421	; wall_sequence	inner wall/outer wall
422	; wall_transition_angle	10	int
423	; wall_transition_filter_deviation	0.25	float
424	; wall_transition_length	1	int
425	; wipe	1	int
426	; wipe_distance	2	int
427	; wipe_speed	0.8	float
428	; wipe_tower_no_sparse_layers	0	int
429	; wipe_tower_rotation_angle	0	int
430	; wipe_tower_x	165	int
431	; wipe_tower_y	250	int
432	; xy_contour_compensation	0	int
433	; xy_hole_compensation	0	int
434	; z_direction_outwall_speed_continuous	0	int
435	; z_hop	0.4	float
436	; z_hop_types	Auto Lift
437	; CONFIG_BLOCK_END

Standard Marlin G-codes

Code	Description
G0	Rapid linear move (X, Y, Z)
G1	Controlled linear move (used for printing and travel)
G5	B-spline curve move (not standard in Marlin; may be ignored)
G28	Auto home all axes. Moves all axes to their endstops (zero position).
G90	Set to absolute positioning (most common mode).
G91	Set to relative positioning (rare, used for manual adjustments).
G92	Set current position (e.g., G92 E0 resets extruder position)

---

Standard Marlin M-codes

Code	Description
M17	Enable all stepper motors
M82	Set extruder to absolute mode
M83	Set extruder to relative mode
M104 Snnn	Set hotend temperature (non-blocking)
M109 Snnn	Set hotend temperature and wait until target reached
M140	Set bed temperature (non-blocking)
M190	Set bed temperature and wait
M106	Set fan speed (eg. M106 S255)
M107	Turn fan off
M201	Set max acceleration for axes (X, Y, Z, E)
M203	Set max feedrate for axes
M204	Set default acceleration (P for print, T for travel)
M205	Advanced settings (minimum feedrate, jerk, etc.)
M220 Snnn	Set speed override (print speed as percentage) (eg. M220 S100 ;Reset Feedrate)
M221 Snnn	Set flow override (extrusion flow percentage) (eg. M221 S100 ;Reset Flowrate)
M400	Wait for all movements to finish
M900	Set Linear Advance (K-factor)
M84	Disable stepper motors

---

Bambu-Specific G-codes

Code	Description
M142	firmware reference (XC1?), Aux fan, chamber temp, set fan speed (eg. M142 P1 R35 S40)

---

Bambu-Specific M-codes

Code	Description
M73	Set build progress and remaining time (used for display/preview)
M1001	Start of print metadata block (job ID, print name, etc.)
M1002	End of print metadata block (job status, logs)
M1003	Custom bed leveling (Bambu's version of mesh calibration)
M1004	AMS / filament path selection or control
M1005	Unknown – likely print status or internal state logging
M1010	AMS info block (e.g., filament type, color, location)
M104 T0 Sxxx Hn	Bambu version of M104 with heating override or flags
M109 T0 Sxxx Hn	Bambu version of M109 (wait for hotend) with control hint
M140 Sxxx Hn	Bambu-specific bed temp set with heating hint
M190 Sxxx Hn	Wait for bed temp (Bambu version with override)
M2000	Set material tuning parameters (e.g., retraction, flow)
M2001	Set filament flow rate tuning
M2002	Set acceleration/jerk parameters
M2003	Set cooling fan tuning or behavior
M2004–M2010	Misc tuning parameters (pressure advance, min/max flow, etc.)
M220 B1	Speed override with Bambu-specific override flag B1
M221 B1	Flow override with Bambu-specific override flag B1
T0 / T1	Tool/filament selection (can trigger AMS actions on Bambu)

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References

• Marlin G-Code Reference
• Bambu Lab Forum Posts
  • Looking for a comprehensive and professional G-Code Manual for Bambu L
  • List of supported g-code commands
  • BBL P1S organized start and end gcode

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Last updated: April 2025