Cura 4.13: A raft where none is chosen

[lothian 1]

Cura 4.13

 

Possible bug found: Cura thinks a model has a bottom where none actually exists.

 

Attempting to print a 134mm ring-shaped object (image below)--the ring is open.  Brim is enabled under Build Plate Adhesion (BPA). Model imported into Cura as either OBJ and STL.

 

 

Before slicing, Cura shades area on the virtual build-plate that fills the ring--this is non-representative of actual BPA setting.  Additionally, Cura does not display shade area to represent a brim along the outside of the ring (see image below). Instead, Cura shades around the perimeter of the build plate. Why.

 

 

After slicing, Cura displays the area inside the ring in yellow (as shown in the image below). Yellow represents top/bottom, yet this object has no material where Cura shows yellow. My printer subsequently prints material into this area (along with a brim) that is thicker than a brim but thinner than a raft. Why.

 

 

What setting might be causing Cura to override the BPA setting and think this model has material where none exists? Or, is this a bug.

 

Edited January 22, 2022 by lothian

[ahoeben 1,968]

It is not a raft, because a raft gets the same color as the brim (cyan).

 

The problem is likely with your model, which may not be manifold ("watertight"). See this article:

https://github.com/Ghostkeeper/SettingsGuide/blob/master/resources/articles/troubleshooting/missing_parts.md#non-manifold-meshes

[lothian 1]

Healed! Thanks for taking the time to reply to my post.

As you suspected, the model was not watertight.

 

 

I still don't understand the shading in Cura that represents the BPA setting; and, why Cura shades the center of the ring regardless of the BPA setting.

 

Edited January 22, 2022 by lothian

[ahoeben 1,968]

Cura was confused by your model. Cura regarded the "extra" solid part in the center as part of the model, not part of the build plate adhesion geometry.