Pressure advance question
Iamturbo1978 last edited by
I am trying to tune pressure advance on my Bowden setup. Using just a standard 20mm cube, I can't get sharp corners even with PA set to 1.0 the corners still buldge a little. And there are little blobs where the printer changes perimeter loops. At first I thought it was a retraction issue, but with coasting set to 2mm the blob at the corner is still there. You can see where the extruder stops extruding.
This issue is driving me up a wall, no matter what I do I can't make it better. I've even changed the jerk and acceleration settings from very high to very low, and nothing makes the corners right. There is always a little buldges and blobs.
Does anyone have any advice that might help me?
Phaedrux last edited by
Try disabling coasting as it may be interacting with presure advance. You may also need more pressure advance. How long is your tube?
Iamturbo1978 last edited by
@Phaedrux Coasting was just to check if my retraction was giving me the issue. If the blob followed the coasting, I would know I had a retraction issue to weed out. But since the blob stays at the corners, I knew it was not from a retraction issue.
My tube is about 600mm long, I was afraid to go too high with the pressure advance since all the information and other peoples examples only go up to 0.500 max. I will try bringing up the PA later tonight.
Iamturbo1978 last edited by Iamturbo1978
After a couple hours of trying to tune PA, I noticed my speed dropped a lot. I'm requesting 60mm/s but I could only get 35mm/s. So I bumped up my jerk from 10mm to 30mm. That worked a little, but I started to skip steps. So I changed my stepper motor from a 0.9 deg 1.2A, to a 1.8 deg 2.0A motor. I have not calibrated the steps yet, and the print is looking a little better.
I did notice something that I need a little better understanding on. With my PA set to 1.5, my extruder pulls the filament back slowly, even though I have the settings through the roof. The extruder can move filament (no hotend, just PTFE tube) at 120mm/s, and during printing, the extruder doesn't look like it is getting close to its limit. is there something I am missing? I am using a true E3D titan extruder, are the settings for the extruder what the filament sees, or what the motor sees? should my extruder values be 3x the standard value (3:1 gearing)?
Here are my current stable settings. I still have to fine tune the extruder settings, they could go up;
M350 X16 Y16 Z16 E16 I1 S2
M92 X80 Y80 Z640 E418.599302 <-- still have to work on steps per mm
M566 X1800 Y1800 Z120 E1400
M203 X24000 Y24000 Z900 E9600 <-- printer can travel at 400mm/s
M201 X3000 Y3000 Z75 E3000
M204 P500 T3000
M906 X1600 Y1600 Z1300 E1500 I20