Pressure Advance Questions....

  • I've been reading, and reading, and I suck with formulas.... I have a small "saw tooth"effect on my corners... Pressure advance of .05 definitely minimized it, but I'm having a really hard time trying to figure out how to convert a K10 from the test print to a duet value.

    If K=10 seems to be the best result with the Marlin Linear Advance test print, what would be a good starting point for the Duet?

    Thanks guys!

  • administrators

    Pressure advance in RRF has always been measured in the natural units, which are seconds. Marlin initially adopted a different measurement, which meant that the pressure advance setting you needed depended on the extruder steps/mm and therefore changed if you altered the extruder, extruder motor, or extruder microstepping setting. A value of K10 is too large to be seconds, so it must be expressed in those units. Later versions of Marlin seem to measure it in seconds, same as RRF.

    As a general guide, non-Bowden extruders need about 0.05sec pressure advance, and an extruder driving a 500mm long Bowden tube needs somewhere between 0.2 and 0.5 seconds.

  • Understood... I’m getting absolutely flawless prints, with only a hint of overextrusion in the corners. Very small amount. I’ve played with extrusion factor, pressure advance, speed, and I’m not sure what next to play with.

    Extrusion is very even and the width is consistent. It’s just the corners where it smooshes over just a tad

  • Moderator

    If your corners are still a little bulged you can increase jerk a bit to make cornering quicker.

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