Extruder behaves strangle when disabling pressure advance

[dragonn]

I am running PA from 0.2 to 0.32 and extuder jerk about 400 but my X/Y moves can easily handle much more. Probaly I could improve extruder performance by chaining motor to 1.8 step, I have that in plans.
Storing PA for every move would be not a good idea. But maybe we can make a exception for disabling PA complete? As you said, identify infill moves.
I am using S3D comments for putting custom commands at start of infill or perimeters.
So maybe something like that:

M572 D1; disables PA for all moves after that command
G1 X5 Y5 E5
.....
M572 D0; enable PA for all moves after that command.

[Phaedrux]

How much does your extruder slow you down during infill that you hope to gain a speed up from disabling it?

0.32 is a substantial amount of PA and 400 is quite low for extruder jerk. For instance, my Titan aero is 3000, same for acceleration.

[dragonn]

I didn't measure it but I am see a big difference when disabling PA, especial when printing small but high objects.
Interesting that you are running Titan with 3000 jerk, for me when I set 1000 it losses so much steps that the print looks like a blocked nozzle. What motor do you have?

Now I am testing with M400 before change PA options. It seems to work just fine Oo

[Phaedrux]

I'm using this motor. https://e3d-online.com/motors-compact-but-powerful-motor

[dragonn]

Interesting,
for now I have 42BYGHM810 and I am planing to change to 42BYGHW811.
M400 causes some blobs on prints but I have an ugly idea, the problem is that I need only to run M400 when changing PA but I ran on/off it before every "feature" so that blob happens when I go from inner to outer perimeter.

[dragonn]

Not sure it this is in any way acceptable to be merged. On one side it isn't a perfect solution for my problem, on other hand applying it would have complete no effect on normal users.
And it need to be applied to option without D parameter too, but I didn't care for testing about it.

[dc42]

On my list to consider.

[zerspaner_gerd]

@dc42

When changing pressure advance, movement is stopped momentarily to avoid sudden under- or over-extrusion (https://forum.duet3d.com/topic/9140/extruder-behaves-strangle-when-disabling-pressure-advance/10)

Does the above with version 2.03beta3 work?

What exactly was changed?
What do I have to write to disable it for the infill.
To activate completely normal M572 D0 S0.6 write?

Found the same problem as dragonn, then depraved my idea again.

P.S .: I have two extruders

[dc42]

In 2.03beta3, when you change pressure advance it waits for all moves in the pipeline to complete, then sets the new pressure advance, then carries on with the next move.

[zerspaner_gerd]

@dc42 said in Extruder behaves strangle when disabling pressure advance:

waits for all moves in the pipeline to complete,

this results in a different disadvantage?