Gradual infill inadequate behaviour

[Dmitrijs 0]

Hello. I am facing a very strange printing anomalies when using gradual infill steps in models with sloped walls (anything over 8°) and any Extra Infill Wall Count more than 0.

The g-code then contains several printing sequences for these infill walls over the same place. It literary overprints same lines two-three times. 

Obviously this causes triple amount of filament on those lines and failed print. Setting higher step sizes will affect behaviour, most of my tests done at 1mm.

Often it in addition to that it generates a second infill wall, even if I choose Extra Infill Wall Count = 1.

I guess this second wall is supposed to be a border between higher and lower densities, but they are too close together to see any infill there.

Overall it feels like Cura is generating all of those "borders" even at layers where those are spaced at intervals shorter than the nozzle diameter.

There is no such behaviour when walls are vertical or less than 7° from vertical. 

This has been observed in v3.6, v4.6 and v4.6.1 at least.  All other settings irrelevant and tests have been carried out with completely default setting in freshly installed Cura as well as with my standard profile.

Unfortunately some of my filaments require very dense infill underneath top surfaces but it is unreasonable to print whole model at 40-50% infill.

If I switch off infill wall, then it generates very short lines of infill along the perimeter at maximum infill density which does not destroy the printed part, but half of the print time is spent for retracts even at 2mm @ 35mm/s. This often causes additional messy problems that are not solvable even with connected infill lines feature ON (then it overprint the infill pattern along the perimeter).

At the most optimal scenario (one infill wall and two gradual steps) it prints over the same line three times, blows up walls with excessive filament and causes the nozzle to catch those walls (sometimes with 1mm z-hop) and detach model from platform.

I have attached a very representative model, but this happens in other models too. This is visible during simulation, so no need printing every time (I found this out late) 

Attached pictures show model printed with my standard profile but at Gradual Infill Steps set to 0 and 2. Also sliced view without infill wall.

 

infill density.STL

[gr5 2,025]

There are 3 settings that affect gradual infill.  We need to know what you set all three to.  Please read this post - CLICK ON MY ICON JUST BELOW TO GET MY REPLY - DON'T CLICK ON THE ENTIRE TOPIC (you'll get that anyway but it will jump to my post).

 

[Dmitrijs 0]

Huh... this is complicated. It happens with any setting as long as there is more than 0 infill walls and more than 0 gradual infill steps. I have tried infill from 0.1% to 80%, step size from 0.5 to 10mm and step count from 1 to 10.

Printed part on those photos was at 50% infill, 2 steps of 1mm (and 0, with no other changes at all).

If I set it to 10 steps I get ten times overprint on the outer infill wall and 8.5 extra infill walls next to it.

Here, I have recorded how it simulates it (and also prints) with ten steps. pay attention how many times it mover over the outer perimeter before starting to print internal ones:

I doubt it is specific to me, so I guess it should be very easy to replicate...

P.S.: Situation with excessive internal infill walls is not as bad with only 2 steps

[Dmitrijs 0]

Does anyone else has this problem?