Pressure advance slowing prints
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I recently started experimenting with pressure advance, and I'm having issues with the print movement slowing significantly on certain features (particularly noticeable on certain arc movements). I understand that having extruder jerk set too low could cause this, but I've experimented with values ranging from 1200 to 4800 and haven't seen any noticeable change in movement speed.
I'm running a geared extruder (Titan) and haven't really been able to find any information on tuning extruder jerk and acceleration so I'm not entirely sure what'd be considered reasonable or safe, but I've been using values of 1000 for accel and 1200 for jerk for quite awhile without any issues.
I'm running a delta with a fairly long bowden and pressure advance seems like something that would be advantageous to have, if I can figure out how to get it dialed in without slowing down movement too much. However at this point I'm not really sure where to look. Any suggestions would be welcome. I'm on firmware version 1.18.
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Hi,
If it can help you (or not) i have completely stop using this function for what you find and on my setup (core XY with titan) more they were mesh on my segment more i get buggy prints…. -
What are your other axes accel/jerk settings? I had a try at turning jerk off completely for my deltas movement axes, to see what would happen and small curved perimeters printed very strangely, slow and over-extruded.
It is possible to run the titan extruder (even with 20mm pancake motor) at accel. 9000 although when I tried it the gears, especially the polymer one sound like they're having a hard time. I have also played with running extruders at very low acceleration like 50mm/s this also seems to work as far as retraction goes.
I think I'd set lower jerk value, maybe just nudge it down to 1000, but raise acceleration to 3000.
I think you would be best to run a sequence of test objects, since all of these settings can be dynamically adjusted, print 10 layers with pressure advance 0.025, then 0.05, then 0.075, 0.1, 0.2 etc.. and see what effect it has. Then chose the best of them, and repeat with acceleration and then jerk.
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Thanks for the tips. That's a great idea of adjusting the parameters every 10 layers, I will give that a try. I am running the same accel and jerk settings on the other axes but have not spent any time tuning these and have been happy with the performance until I tried to use pressure advance.
