Max flow21 mm³/s Top speed250 mm/s ↑ top
Bambu filament settings · live

One number decides everything. It’s not on the label.

Set your printer, nozzle, spool and speed below. The figure here is your hotend’s real volumetric ceiling — watch it move as you change them.

Max volumetric flow — mm³ of plastic the hotend can melt per second. Drag the speed slider and this is the number that does, or doesn’t, keep up.

Max volumetric flowupdates live
21 mm³/s The single value Bambu Studio can’t guess for you
Effective top speed
250mm/s
you asked for 300
target 300 → clamped
Pressure advance K
0.02
starting point — refine on-machine
Flow ratio
0.98
Bambu’s calibrated default
Retraction length
0.8mm
direct drive · X1 Carbon
hotend ceiling 21 mm³/s · Bambu default 21 for this combination ⚠ clamped — your speed asks for more than the hotend can melt
Set it up↺ reset
01Printer12 models
02Nozzle
Diameter
Hardness
03Filament
Family
Type
Brandthe difference
Bambu only profiles its own spools. Pick what you actually bought.
Brand sets the profile name today; per-brand flow overlays land in v2.
04Speed
Target print speed
300mm/s
20200400600

Push past the ceiling and the giant number stops climbing — the slicer caps you there. For this combination it clamps past ~250 mm/s.

Advanced
Your numberslive
21mm³/smax volumetric flow
Top speed
250 mm/s
Pressure adv. K
0.02
Flow ratio
0.98
Retraction
0.8 mm

Is this right for your spool?

Here’s what to watch as you change the inputs — and how sure we are.

!
That speed is faster than the hotend can melt
300 mm/s at 0.2 mm layers × 0.42 mm lines asks for 25.2 mm³/s — past PLA Basic's 21 mm³/s ceiling on the X1 Carbon. You'll really get 250 mm/s. Want more? Drop the layer height.
Against Bambu stock
flow 0.98 · ceiling 21 mm³/s
Source
Bambu Studio profiles
Did these work?
Full settings 32 fields · the complete profile
SettingValueJSON field
Identity
Vendor Generic filament_vendor
Type PLA filament_type
Extruder variant Direct Drive Standard filament_extruder_variant
Physical
Diameter (mm) 1.75 filament_diameter
Density (g/cm³) 1.24 filament_density
Price ($/kg) 0.00 filament_cost
Shrinkage 100% filament_shrink
Required nozzle HRC 3 required_nozzle_HRC
Softening temp (°C) 100 temperature_vitrification
Temperature
Nozzle — other layers (°C) 220 nozzle_temperature
Nozzle — initial layer (°C) 220 nozzle_temperature_initial_layer
Recommended nozzle min (°C) 190 nozzle_temperature_range_low
Recommended nozzle max (°C) 240 nozzle_temperature_range_high
Textured PEI plate (°C) 55 textured_plate_temp
Cool plate (°C) 35 cool_plate_temp
Engineering plate (°C) 55 eng_plate_temp
Smooth PEI / High Temp (°C) 55 hot_plate_temp
Cool Plate SuperTack (°C) 45 supertack_plate_temp
Chamber (°C) 0 chamber_temperatures
Flow & speed
Max volumetric speed (mm³/s) 21 filament_max_volumetric_speed
Flow ratio 0.98 filament_flow_ratio
Retraction
Length (mm) 0.8 filament_retraction_length
Retraction speed (mm/s) 30 filament_retraction_speed
Deretraction speed (mm/s) 30 filament_deretraction_speed
Z hop (mm) 0.4 filament_z_hop
Cooling
Min fan speed (%) 80 fan_min_speed
Max fan speed (%) 100 fan_max_speed
Slow-down layer time (s) 8 slow_down_layer_time
Fan off, first N layers 1 close_fan_the_first_x_layers
Overhang fan (%) 100 overhang_fan_speed
Overhang threshold 95% overhang_fan_threshold
Compatibility
Compatible printers Bambu Lab X1 Carbon 0.4 nozzle compatible_printers
Download the profile

A .zip with the Bambu Studio .json (drop-in import) and a Markdown summary of every value and why.

K
After import: run Flow Dynamics Calibration. The pressure-advance K (0.02) lives in the summary, not the JSON — Bambu manages it per-printer.
What’s next? Try PETG HF · Same on A1 mini · or
Your numbers
21mm³/s max flow
Top speed
250 mm/s
Pressure adv. K
0.02
Flow ratio
0.98
Retraction
0.8 mm
Bambu filament settings
filamentspec
PLA Basic · Generic
Generic PLA Basic @X1C 0.4
Printer X1 Carbon Nozzle 0.4 mm · stainless Material PLA Basic Brand Generic
Max volumetric speed
21 mm³/s
Enter in Bambu Studio → Filament → Max volumetric speed. Every move auto-throttles to stay under it.
Effective top speed
250 mm/s
Pressure advance K
0.02
Flow ratio
0.98
Retraction
0.8 mm
Defaults from Bambu Studio's shipped profiles, resolved for this printer × nozzle × material by filamentspec. Verify with a calibration print before trusting on a long job.
After import
Run Flow Dynamics Calibration and enter K = 0.02. Do not tick “Adaptive volumetric speed”.
Scan to reopen
https://www.filamentspec.com/?printer=X1C&nozzle_diameter=0.4&nozzle_material=stainless&material=PLA-Basic&target_max_speed=300&brand=Generic&build_plate=textured_plate
filamentspec · free Bambu filament profile generator