Cura: [3.5.1] [3.5.0] Cura does random connections from supports - support material intersects model

[P3D-1]

Application Version
3.5.0
3.5.1 (bug still there)

Platform
W7

Printer
Ultimaker S5

Steps to Reproduce
Open the project file, slice, enable layer view
UMS5_Breakaway_Problem.zip

Actual Results
Random Breakaway lines intersecting the model, leading to unwanted print results.

Expected results
No model intersection

Additional Information

[BagelOrb]

FYI: This bug is unrelated to Connect Polygons.

Perhaps this is something which @smartavionics can shed light into off the top of his head?

[BagelOrb]

See also https://community.ultimaker.com/topic/24775-breakaway-support-intersects-model-with-cura-350/

[smartavionics]

This slices OK for me using my master branch based Cura so perhaps the problem has already been fixed upstream for a future release. If you want to try for yourself, you could install one of my Cura releases that are based on the master branch.

https://www.dropbox.com/sh/s43vqzmi4d2bqe2/AAADdYdSu9iwcKa0Knqgurm4a?dl=0

[BagelOrb]

@Appesteijn We should find out which commit fixed this issue and cherry-pick that commit to the 3.5 branch before 3.5.1

I would categorize this as a major bug.

[diegopradogesto]

Devs. see CURA-5828

[P3D-1]

The issue is still there for me in Cura 3.5.1.

[smartavionics]

Sorry, to hear that. I guess the devs have fixed it for the master branch but that hasn't made it into 3.5.1. As I mention above, my master branch builds are available if you are in a position to use them.

[diegopradogesto]

Nope, sorry. We couldn't find the exact issue that caused that in 3.5. Since it is fixed in master branch, we prioritized some other bug fixes.

[smartavionics]

Do all of the infill patterns cause this problem? If not, could another pattern be used as a workaround? Does turning off the connecting lines setting make a difference?

[P3D-1]

Do all of the infill patterns cause this problem? If not, could another pattern be used as a workaround? Does turning off the connecting lines setting make a difference?

All support patterns available show this problem. Turning off the "connect support lines" option doesn't make a difference.

Thanks everyone for your input and hard work, by the way! Seems like I have to downgrade to 3.4.1 or use the master branch builds kindly provided by @smartavionics for the time being, though.

[smartavionics]

Oh, well it was worth asking the question.

[BagelOrb]

I've found the problem together with @Appesteijn

The support bottoms automatically connect infill polygons independent of any user setting.

FffGcodeWriter::addSupportBottomsToGCode line 2461

The bug is still present in 3.5.1 and in master.

The Cura team will discuss what to do with this tomorrow.

[Appesteijn]

This solves your problem for me.

[BagelOrb]

For now: a work-around is to set the Support Floor Pattern to ZigZag or to Lines

[smartavionics]

it's great that you have a workaround. I wonder why I am not seeing the problem here.

[BagelOrb]

Please set the visualization coloring to line type. This is hard to look and understand.

The problem might be easier to see on the standard benchy model.

PS: I'm sorry for introducing this bug in the first place!!! Please forgive me.

[smartavionics]

[P3D-1]

Thanks @BagelOrb for the workaround, this also works for me in 3.5.1. You are forgiven ;)

[BagelOrb]

I don't know where the bug comes from. It's some sort of memory corruption. I can't explain why you don't reproduce the bug now @smartavionics

I do know that the bug has been fixed in my PR tho.

[P3D-1]

Seems to be fixed in Cura 3.6.0. Thanks for your work, everyone!

[diegopradogesto]

Thanks for the feedback!