Inner wall speed
How fast the walls you can't see are printed. They can go fast; the limit is how much plastic the nozzle can melt per second.
How it works
Inner walls are hidden between the outer wall and the infill, so their finish doesn't matter. What matters is that enough plastic comes out: at 300 mm/s, with 0.45 mm lines and 0.20 mm layers, the nozzle needs 27 mm³/s, and a regular PLA only handles 21. The slicer knows this and trims the actual speed to what the filament allows.
That's why raising this number past the filament's limit saves nothing.
When to change it
- Almost always: leave it at 300 mm/s; the printer already adjusts it to the filament.
- A large part in a high-flow filament, which melts more plastic per second: you can make use of up to 400 mm/s.
- A phone case in TPU (flexible filament) or another slow filament: the filament profile is in charge and the actual speed ends up well below this value.
Typical values
| Value | What for |
|---|---|
| 150 | Delicate parts or slow filaments |
| 300 | Defaultdefault |
| 400 | Only with high-flow filaments |
Watch out for
- If the inner walls push on the outer wall and show on the surface, the problem is usually the flow (how much plastic comes out), not the speed.
- The maximum flow is set in the filament profile (“Max volumetric speed”).
Goes well with
What Bambu Studio saysits help card, quoted
What Bambu Studio says
Speed of inner wall
Bambu Studio tooltip for this setting · AGPL-3.0
Read more at the official source
In your profile0.20mm Standard @BBL A1 · 300 mm/s · changes with the profile
In Bambu Studio, the profile 0.20mm Standard @BBL A1 sets it to300 mm/s
In other slicers
- Orca Slicer
- Inner wallSpeed › Other layers speed
- PrusaSlicer
- PerimetersSpeed › Speed for print moves
- Cura
- Inner Wall SpeedSpeed
Names taken from each program's code (Orca Slicer 2.4.2, PrusaSlicer 2.9.6, Cura 5.13.0). Credits