How to tune Acceleration and Jerk on large pellet printer
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I'm a bit lost as where to start. I've got a large-format 3d printer that uses a screw pellet extruder. I'm trying to implement pressure advance, but what I'm noticing is that when I'm satisfied with values of pressure advance, it substantially slows down my print time. I can speed the print back up by increasing the j**k values in X and Y, but that causes my extruder to skip steps. So my question is, where do I start since acceleration and j**k in X,Y, & E all affect each other (with pressure advance enabled).?
The values I only know for sure are max accelerations for X and Y, and RPM of the extruder.
Thanks
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@p8blr The usual culprit which fits your description of events is extruder j**k being too low. Given that in any G1 move the axes travel and extruder travel have to be synchronised, then it's fair to say that if extruder j**k is too low, it will affect the X and Y axes as well. Conversely, if extruder j**k is high then in order to keep X, Y and E synchronised, it will effectively be overridden by the axes j**k values. Therefore, it is safe to set extruder j**k to a "silly high" number where it cannot interfere with any G1 Xn Yn En move. The only time extruder j**k could potentially come into affect (other than when it is set low and pressure advance is being used) is for extruder only moves which don't involve a reversal of direction (I can't think of any such moves).