3d-printing May 6, 2026 ◑ 9 views ◯ 2 min read

Pressure Advance Calibration for OrcaSlicer and Klipper

pressure advanceklipperorcaslicercalibrationlinear advance

What Pressure Advance Fixes

At corners and direction changes, the extruder continues pushing filament briefly after the head slows down. This causes blobbing at corners and rounded outer edges instead of sharp ones. At high print speeds this becomes very visible.

Pressure advance (Linear Advance in Marlin) pre-compensates — reducing extruder pressure just before deceleration and increasing it before acceleration. Result: sharp corners, clean seams, better quality at speed.

Firmware Names

Klipper: pressure_advance in printer.cfg
Bambu machines: handled automatically, tunable via flow calibration
Marlin: LINEAR_ADVANCE with K-factor
RepRapFirmware: Pressure Advance per tool

OrcaSlicer Calibration

Go to Calibration → Pressure Advance / Linear Advance. Select the filament profile you want to calibrate. Click Print PA Test.

OrcaSlicer prints a test grid where each section uses a different PA value. Print at the speed you normally print at.

Reading the Result

Look at corners of each test band:

Too low: corner blobs, rounded edges, excess material at corners
Too high: gaps or underextrusion at corners and line starts
Correct: sharp clean corners, consistent line width through transitions

Find the cleanest band. Note the PA value shown on or adjacent to it.

Setting the Value

In OrcaSlicer: Filament settings → Filament → Pressure Advance — enter the value. Saves per-filament profile automatically.

In Klipper (printer.cfg):

[extruder]
pressure_advance: 0.045

Run SAVE_CONFIG to persist across restarts.

Typical PA Values

Setup	Typical Range
Bowden (Ender 3, CR-10)	0.4 – 1.0
Direct drive (MK4, Voron)	0.02 – 0.08
CoreXY direct (Bambu, Voron)	0.02 – 0.06
High-speed CoreXY	0.01 – 0.04

Important: PA Is Speed and Material Dependent

A PA value calibrated for PLA at 150mm/s will be wrong for PETG or for PLA at 300mm/s. Calibrate once per filament type at your most common print speed. Set the value in the filament profile so it loads automatically when you switch materials.

Recalibrate when: switching filament type, significantly changing print speed, replacing hotend or extruder, or after a firmware update that changes motion behaviour.