@dc42 said in Asymmetric Pressure Advance
.... Extruder jerk complicates this a little, however RRF uses extruder jerk rarely, mostly only when the slicer has produced bad GCode e.g. tiny segments for which the extrusion amount is specified with too few decimal places.<
Looking at this there is clearly a scenario in which extruder jerk would be implemented (not PA related?) which I have not thought of, but looking only at the PA formula I come to the conclusion that extruder jerk will automatically be implemented any time that there is an axis acceleration or deceleration since according to the formula Vactual = Vrequested + (K*actual acceleration), with the variables in the equation all referring to the extruder parameters.
According to this there would be an instantaneous velocity change required by the extruder the moment that any acceleration or deceleration is required i.e jerk. This would be irrespective of whether or not the position axis required jerk or not.
This jerk obviously has to take place by default at the end of any acceleration or deceleration phase, but should only take place at the beginning of an acceleration or deceleration phase if there is also jerk taking place on the position axis i.e such as at corner transitions (but not at line starts or ends).
What is your take on this?