Filament diameter
The filament thickness the program uses to work out how much to push. If it doesn't match the real one, too much or too little plastic comes out.
How it works
The extruder doesn't measure plastic: it pushes millimeters of filament. The program turns the plastic each line needs into millimeters to push using this diameter. Set it smaller than the real one and it pushes too much; set it bigger and it pushes too little.
The error grows with the square: a 0.05 mm difference on 1.75 is almost 6% of plastic.
When to change it
- Almost never: nearly all current printers, like the A1, use 1.75 mm filament; leave the diameter yours asks for.
- A spool that measures differently along its length: don't compensate here. Change spools or adjust flow with the test in the Calibration menu.
Typical values
| Value | What for |
|---|---|
| 1.75 mm | Default; the A1's filamentdefault |
| 2.85 mm | Other printers; won't fit the A1 |
Watch out for
- To correct the amount of plastic there's “Flow ratio” (with the flow test), not this value.
- If you measure the spool, use calipers at several points and in two directions: filament isn't always perfectly round.
Goes well with
What Bambu Studio saysits help card, quoted
What Bambu Studio says
Filament diameter is used to calculate extrusion in gcode, so it's important and should be accurate
Bambu Studio tooltip for this setting · AGPL-3.0
Read more at the official source
In your profileBambu PLA Basic @BBL A1 · 1.75 mm
In Bambu Studio, the profile Bambu PLA Basic @BBL A1 sets it to1.75 mm
In other slicers
- Orca Slicer
- DiameterFilament › Basic information
- PrusaSlicer
- DiameterFilament
- Cura
- No clear equivalent.
Names taken from each program's code (Orca Slicer 2.4.2, PrusaSlicer 2.9.6, Cura 5.13.0). Credits