Flow ratio
Multiplies all the plastic that comes out with this filament. It's where the flow test result is stored.
How it works
The program works out how much plastic each line needs, but every filament changes volume slightly when it melts and cools. This number corrects every line at once: at 0.98, 2% less than calculated comes out.
The recommended range is 0.95 to 1.05. The right value comes from the test in Calibration › Flow rate.
When to change it
- Top surfaces with grooves between lines: raise it 0.01 at a time.
- Smeared lines, ridges or oversized parts: lower it 0.01 at a time.
- You switched filament brand: run the flow test and store the result here.
Typical values
| Value | What for |
|---|---|
| 0.98 | PLA Basicdefault |
| 0.95–1.05 | Recommended range |
Watch out for
- Don't use it to fix a single area of the part: it changes every line.
- Before touching it, dry the filament: moisture also gives rough surfaces.
Goes well with
What Bambu Studio saysits help card, quoted
What Bambu Studio says
The material may have volumetric change after switching between molten state and crystalline state. This setting changes all extrusion flow of this filament in gcode proportionally. Recommended value range is between 0.95 and 1.05. Maybe you can tune this value to get nice flat surface when there has slight overflow or underflow
Bambu Studio tooltip for this setting · AGPL-3.0
Read more at the official source
In your profileBambu PLA Basic @BBL A1 · 0.98
In Bambu Studio, the profile Bambu PLA Basic @BBL A1 sets it to0.98
Helps with
In other slicers
- Orca Slicer
- Flow ratioFilament › Flow ratio and Pressure Advance
- PrusaSlicer
- Extrusion multiplierFilament
- Cura
- FlowMaterialAs a % (100% = 1.0).
Names taken from each program's code (Orca Slicer 2.4.2, PrusaSlicer 2.9.6, Cura 5.13.0). Credits