Slice this file with the following magic setings to get a file you can use for tuning pressure advance with Klipper's TUNING_TOWER command:

• Overhang Wall Angle: 1°
• Overhang Wall Speed: 20%
• Zero infill
• Zero top layers
• Zero minimum layer time
• Single perimeter
• Seam at fixed postion in rear (+Y direction)
• The actual speed and acceleration you want to tune for

This will produce a gcode file where each layer is a circle, cycling between phases of:

• Short high-speed segment
• Medium length low-speed segment (20% speed)
• Long high-speed segment
• Z travel up at seam

then repeating in the next layer.

Run the print with a command like:

TUNING_TOWER COMMAND=SET_PRESSURE_ADVANCE PARAMETER=ADVANCE FACTOR=0.002The total height is 40 mm, so it will test PA K values from 0 up to 40 times your chosen factor. The factor of 0.002 gives a reasonable range (0 to 0.08) for rigid filaments with direct drive extruder. For flexibles or bowden you will need to adjust it and may want to add a nonzero START.

After printing, simply measure from the bottom to the layer with the least visible transitions between slow and fast. Multiply this distance by your FACTOR, and that is the correctly calibrated PA value to use.

Category: 3D Printing Tests