Bridge flow
Multiplies the amount of plastic the nozzle releases while it lays a bridge across thin air. A little under 1 gives lighter strands that sag less.
How it works
A bridge is a set of lines printed over empty space, from one support to another, like the top of a window or the roof of a hole. Each strand gets stretched and holds itself up by its own tension. If it's too heavy, it sags; if it's too thin, it breaks or leaves gaps with the one next to it.
This factor multiplies the normal amount of plastic only on bridges on the outside of the part. At 1 (the default) the line gets the calculated amount of plastic; at 0.9 it gets 10% less and comes out tighter.
When to change it
- A box with a window or an arch where the strands of the ceiling sag or leave little hairs underneath: lower it to 0.9 or 0.95.
- A bridge with gaps between lines or strands that snap: leave it at 1 or raise it a little, and check the bridge speed and the fan.
Typical values
| Value | What for |
|---|---|
| 0.9 | Tighter, cleaner bridges |
| 1 | Defaultdefault |
| 1.1 | Only if the strands come out too thin |
Watch out for
- A bridge that sags usually has another cause: too much speed, too little fan or a bridge that's too long. This setting fine-tunes; it doesn't fix.
- It only affects bridges on the outside; internal ones (over the infill) are handled separately.
Goes well with
What Bambu Studio saysits help card, quoted
What Bambu Studio says
Decrease this value slightly(for example 0.9) to reduce the amount of material for bridge, to improve sag
Bambu Studio tooltip for this setting · AGPL-3.0
Read more at the official source
In your profile0.20mm Standard @BBL A1 · 1
In Bambu Studio, the profile 0.20mm Standard @BBL A1 sets it to1
Helps with
In other slicers
- Orca Slicer
- Bridge flow ratioQuality › BridgingIn Orca it only affects external bridges; internal ones use internal_bridge_flow.
- PrusaSlicer
- Bridge flow ratioAdvanced › Flow
- Cura
- Bridge Skin FlowExperimentalAs a % and only with bridge_settings_enabled; bridging walls use bridge_wall_material_flow.
Names taken from each program's code (Orca Slicer 2.4.2, PrusaSlicer 2.9.6, Cura 5.13.0). Credits