Process › Speed› Jerk(XY)max_volumetric_extrusion_rate_slope_negative
Max volumetric slope (decrease)
How much the plastic flow can drop each second. It's the partner of the increase slope, for when the head goes from fast lines to slow ones. 0 turns it off.
How it works
When going from a wide, fast line to a thin, slow one, the pressure built up in the nozzle keeps pushing plastic for an instant, and too much comes out right as the slow line starts. This limit makes the flow come down gradually instead of dropping all at once.
When to change it
- Most parts: leave 0.
- A figure with a bulge at the start of each outer wall loop, right after the infill: try 20–40.
Typical values
| Value | What for |
|---|---|
| 0 | Default; no limitdefault |
| 30 | Smoothed flow drops |
Watch out for
- If your printer has calibrated pressure advance (Bambu printers calibrate it themselves with Flow Dynamics Calibration), it already makes up for almost all of this: calibrate it before touching this value.
Goes well with
What Bambu Studio saysits help card, quoted
Read more at the official source
In your profile0.20mm Standard @BBL A1 · 0 mm³/s²
In Bambu Studio, the profile 0.20mm Standard @BBL A1 sets it to0 mm³/s²
In other slicers
- Orca Slicer
- Extrusion rate smoothingSpeed › AdvancedA single value for flow going up and going down.
- PrusaSlicer
- Max volumetric slope negativeSpeed › Pressure equalizer (experimental)
- Cura
- Gradual flow max accelerationMaterialA single value for raising and lowering the flow; it needs gradual_flow_enabled.
Names taken from each program's code (Orca Slicer 2.4.2, PrusaSlicer 2.9.6, Cura 5.13.0). Credits