Process › Speed› Other layers speedbridge_speed

Bridge speed

How fast bridges are laid down, the lines printed through the air from one support to another. It goes slowly so the strand cools as it crosses and doesn't sag.

How it works

In a bridge the plastic has nothing underneath: it stretches from one side to the other and holds itself up by its own tension. If the nozzle moves fast, the strand reaches the other support still soft and sags in the middle. At 50 mm/s (the factory value) the fan has time to harden it along the way.

Walls that hang 100% have their own speed, in the “100%” field under “Slow down for overhang”.

When to change it

A shelf or the ceiling of a box with a bridge longer than 40 mm that sags: lower it to 30 mm/s and turn up the cooling.
A part with short bridges, like small windows or slots, where time matters: raise it to 80 mm/s.

Typical values

Value	What for
30	Long bridges
50	Defaultdefault
80	Short bridges

Watch out for

Slower isn't always better: every printer and filament has its own sweet spot, and below it the bridge stops improving. Go down 10 mm/s at a time and compare.
“Bridge flow” and “Thick bridges” help fine-tune the result.

Goes well with

Bridge flow Thick bridges 100%Bridge direction

What Bambu Studio saysits help card, quoted

What Bambu Studio says

Speed of bridge and completely overhang wall

Bambu Studio tooltip for this setting · AGPL-3.0

Helps with

Bridges sag

In other slicers

Orca Slicer: ExternalSpeed › Overhang speed › BridgeIn Orca it's only for external (visible) bridges; internal ones use internal_bridge_speed.
PrusaSlicer: BridgesSpeed › Speed for print moves
Cura: Bridge Skin SpeedExperimentalOnly with bridge_settings_enabled; bridging walls use bridge_wall_speed.

Names taken from each program's code (Orca Slicer 2.4.2, PrusaSlicer 2.9.6, Cura 5.13.0). Credits