Prime Tower Brim not working

[rbrome]

Cura Version

5.3.1

Operating System

macOS Ventura 13.5

Printer

Ultimaker S5

Reproduction steps

1. Import large model that uses two materials (Ultimaker transparent PLA and a third-party wood filament) from STL files.
2. Align two models.
3. Choose Build Plate Adhesion Type: None.
4. Enable Prime Tower.
5. Enable Prime Tower Brim.
6. Slice.

Actual results

No brim on prime tower. Tried printing anyway and the tower fell over, ruining the print.

Expected results

A brim on the prime tower.

Add your .zip and screenshots here ⬇️

It's super common to need a brim on the prime tower even when one is not needed on the model. This should work. And if this somehow intended behavior (but why????) then the Prime Tower Brim option should be grayed out when Build Plate Adhesion is set to None. But again, why would that be intended behavior?! Having to print a skirt to get a Prime Tower Brim is a silly and wasteful workaround that accomplishes nothing. If it works with a skirt then it should work with "None".

[GregValiant]

Thanks for the report.
As I mentioned on the Forum this appears to be related to #16299 , #16162 , #14725 , #14810 , #14822 , #14983 so there certainly appears to be issues with the Support Brim and Prime Tower Brim when Bed Adhesion is set to None. The Cura team is aware of this problem and @MariMakes posted this yesterday:
"Quick update from our side.
We were able to resolve the issue here: Ultimaker/CuraEngine#1917

That means that we can have a fix for this problem in the upcoming release.
Thanks for all the reports, apologies for the inconvenience"

Setting to "Skirt" is a workaround, not a fix. The repair for this bug has taken a while and yes, Skirt does use material. An 800mm long skirt at .2 LH x .4 LW uses 10mm of 2.85 filament for a single loop. Percentage wise - compared to what most folks throw away in their supports it isn't much. I think using a skirt now is better than holding off on a print for another couple of months until the new release is out.

I'll mark this as a duplicate and go ahead and close this as it is now cross-referenced with the other reports and a fix is in place. I hope you understand.