Tuning the Nimble & pressure advance
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I tried pressure advance on my Nimble and it really slowed down the print. I raised the jerk settings and this increased the printing speed, but this is in contradiction with Zesty's recommendation to use a low jerk value (40) and leave it at that. Just in case I printed without retraction, and obviously I was getting some stringing.
How should I approach further tuning? Will increasing acceleration (Zesty's recommendation for the Nimble) have the same effect as increasing jerk (Duet's recommendation for slow prints with PA)?
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@bartolomeus I am also in the middle of tuning a nimble. Jerk E40 works for me, so far, hence leave that fixed. What pressure advance have you tried? I am using 0.03. 0.02 to 0.05 seems the range. Seems non-linear pressure advance is not necessary at the early stage of tuning. The real speed setting is having a high XY jerk, mine now 1000, and going well speed-wise. I tried zero jerk and very high acceleration and that didn't go well !!!!
[ Jerk seems an undesirable mechanical impost on the mechanics, I would prefer just high acceleration, but jerk is necessary to deal with curves. Would be good if curves had a more elegant solution.]
Generally the extruder is a slave to the XY movements but it would be good to know the full dependency there in the underlying algorithms? -
I tried 0.16 first. I know it's high, but it's a setting that was posted on the discord channel and it looked like he was using zero retraction. So, I hoped maybe with this setting I wouldn't get stringing, but I did. Apart from that, corners were generally nice, exept on very short moves (around the rear window on a benchy).
My next try is going to be 0.05, with E40 on the nimble, 240 max accelleration and less retraction (0.5mm) than I use without PA (0.8 to 1mm).
I believe my current X and J jerk is 900.
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@bartolomeus I recall the strongly recommended E acceleration setting for the Nimble is 120. ie try everything else first.