Bug Unwanted Circle in The Brim on all Models in Cura 5.1+

[Garywoo 0]

How do I get rid of this random circle in the brim path of my slice?

 

It's appearing when slicing all models after I upgraded to Cura 5.1.1. It also appears in Cura 5.2 beta. It does not occur in Cura 5.0 when slicing the same model shown in the screenshot. I also installed Cura 5.1 to test, and it also appears there.

Edited October 1, 2022 by Garywoo

[GregValiant 1,415]

That looks a lot like a purge tower.  In the Dual Extrusion settings you can turn it off.

If you happen to be using one extruder for the model but the Build Plate Adhesion is set to the other extruder you will get that.  I think if you disable an unused extruder (there is a check box) then it will go away as well.

[Garywoo 0]

Thanks Greg, I clicked on Settings > Extruder 2 > Disable Extruder, and this stopped the circle being generated.

 

Where do I define which extruder prints the Build Plate Adhesion?

[GregValiant 1,415]

My disclaimer:  I have a "virtual" dual extruder Ender 3 Pro in Cura that I use for troubleshooting.  I have no real life experience with them.

When both extruders are enabled and with a model on the build plate you should have the option in the Bed Adhesion section.  You can see it in the image below.  Next to the Settings Search box is an icon with three lines.  Click on it and set the visibility to "All".

 

One thing I've learned about dual extruders is they each have there own settings.  I have to be very careful checking all the settings for both extruders by switching back and forth between extruders.  It's fairly easy to make a mess.

[sirspat 0]

it's the prime tower.

I couldn't find the setting in cura that changes, but in
%appdata%/cura/5.2/quality_changes/custom-printer.cfg

i changed
prime_tower_enable = True
to
prime_tower_enable = False


if you have grep installed, then you might run a recursive grep to find the proper file:
grep --color -rni "prime_tower_enable = True" %appdata%/cura

Edited October 8, 2022 by sirspat

[gr5 2,271]

6 hours ago, sirspat said:

I couldn't find the setting in cura that changes,

I think it's hidden if you have a profile that doesn't allow the prime tower?  Anyway just type "tower" in the search box above the settings and the setting should show up (again - unless it's irrelevant).

[MariMakes 206]

That looks like a rogue prime tower. 
Can you try to enable your second extruder again to disable the primetower?

You can just follow the instructions in this gif: