problems with pressure advance calibration

[Veti]

whats your e acceleration. pressure advance needs high numbers for that to work.

also check out the guide i just posted

https://forum.duet3d.com/topic/20558/pressure-advance-tuning-like-klipper

[Veti]

also what kind of setup do you have?
direct drive or bowden?

[nick9one1]

thanks. about 650mm bowden.
its a BLVMGN core XY

M566 X820.00 Y820.00 Z24.00 E300.00            	; set maximum instantaneous speed changes (mm/min)
M203 X20000.00 Y20000.00 Z600.00 E2000.00      	; set maximum speeds (mm/min)
M201 X3000.00 Y3000.00 Z100.00 E5000.00        	; set accelerations (mm/s^2)
M906 X1100 Y1100 Z1100 E1100 I30               	; set motor currents (mA) and motor idle factor in per cent

[nick9one1]

@Veti Thanks. Printing your modified test cube now.

I set M201 X500 Y500 in config.g

Sliced the cube as per the instructions. 100mm/s, 0.3 layer height, 0% infill, and M572 D0 S{layer_z*0.02} in the layer change g-code.

the only slight alteration I made was to ensure the later changes were in the middle fo a face, not at the corner. I think its easier to identify the correct pressure advance this way.

[Veti]

depending on the quality of your bowden tube you might need to go above 1 as 650mm is quite long

and you dont need infill for the test qube

[nick9one1]

@Veti

thanks. It was just the top layers I forgot to set to 0. Infill is already 0 with 3 walls.

[nick9one1]


[Veti]

that doesnt look to good to begin with.

about the middle looks a bit better then the rest.

[Phaedrux]

@nick9one1 said in problems with pressure advance calibration:

M566 X820.00 Y820.00 Z24.00 E300.00

Increase your E jerk. Try 3000.

[nick9one1]

thanks. Increased Ejerk to 3000 and printing again, but only 2 walls this time for speed.

The previous print was 100mm/s

[nick9one1]

Looking much better at 3000 e jerk. Thanks for that tip.

Around halfway looks about the best.
I can see the right side of each new layer is changes but not the end of previous layer -how do I tune this?


[Phaedrux]

Run another test but zero in on the area from the middle area and use finer steps between jumps.

For the bulge from layer change you can also increase your Z axis jerk and accel a bit more. Try M566 Z60 and M201 Z200 or higher.

Do you have retract on layer change enabled in the slicer as well? That can help.

[nick9one1]

@Phaedrux said in problems with pressure advance calibration:

retract on layer change

Thank you. Yes I have retract on layer change enabled

I've changed the z values you suggested and set the slicer to start the pressure advance at 0.035 in increments to 0.055. Printing now

[nick9one1]

I'm definitely getting closer..

I think pressure advance is well tuned now, but I still have extra extrusion on the left.

This is with ;
M566 Z90
M201 Z300

my original settings were;
M566 Z24
M201 Z100

[Phaedrux]

Turn off wipe while retracting and re-run the test.