Ghost/Nonexistent Walls

[Cogster 0]

Im on cura 5.8. I made a model in tinkercad. I exported it. I put it into cura. I sliced it at 0.1 mm layer height. It doesnt print this section and this section only. I switched to 0.2mm, and the gap did get smaller. I looked at the STL in blender and nothing seems off, it is just 2 right triangles.

Edited November 23 by Cogster

[GregValiant 1,409]

With that model loaded in Cura - use the "File | Save Project" command and post the 3mf file here.

 

I'm going to go out on a limb and take a guess...

Any model can have surfaces that are "facing inside out" (AKA "flipped normals").  Blender seems to be prone to doing that.

For many model-uses those flipped normals don't matter, but for slicing for 3D printing they do matter because the slicer can't figure out where the "interior volume" ends and the "outside world" starts.

There should be some tools in Blender that allow you to flip a surface so it is facing the correct way.  You can also use a tool like MS 3D Builder (from the Microsoft store) to repair a model.  There are on-line repair sites as well.

In Cura, you can load the "Mesh Tools" plugin from the MarketPlace. It will inform you when you open a model file if there are problems in the model.  It has some repair capability for small issues as well.

Using the "X-Ray" view tool might show red surfaces which are flipped surfaces,.

When surfaces on the top of a model are red (indicating they need "anti-gravity supports") the model definitely needs repair.

The red areas here kept this Jeep model from slicing.  Once they were repaired there as no problem.  The "bad surfaces" match up perfectly when all the pieces are assembled and so they were not visible, but Mesh Tools knew something was wrong.

 

 

Edited November 21 by GregValiant

[Cogster 0]

7 hours ago, GregValiant said:

With that model loaded in Cura - use the "File | Save Project" command and post the 3mf file here.

 

Ah yes i forgot about that. here it is

also I dont think its a flipped normal proSharpie Adapter Ender 3 V3 SE.stlblem as the surface is half filled in but it is one single face in blender, so it would need to be flipped on one part but not the other and thats impossible. Either way, the STL is also included.

SharpieAdapter.3mf

[GregValiant 1,409]

Better.

You have "Coasting" turned on.  Cura only previews moves that have extrusions.  A coasting move is a travel move so it isn't displayed.  That leaves the characteristic gap.  The gap size is determined by the coasting volume.

Just turn coasting off and check the preview.  You can turn it back on before saving the file.

You also have "Slicing Tolerance" set to "Exclusive".  That's something that isn't done very often.

[Cogster 0]

34 minutes ago, GregValiant said:

Better.

You have "Coasting" turned on.  Cura only previews moves that have extrusions.  A coasting move is a travel move so it isn't displayed.  That leaves the characteristic gap.  The gap size is determined by the coasting volume.

Just turn coasting off and check the preview.  You can turn it back on before saving the file.

You also have "Slicing Tolerance" set to "Exclusive".  That's something that isn't done very often.

Ah so nothing is actually wrong?

Also, I just set it to exclusive because I thought the tolerances between parts would be better because it isnt going outside of the actual model. Maybe I'm wrong.

[Slashee_the_Cow 480]

1 hour ago, Cogster said:

Also, I just set it to exclusive because I thought the tolerances between parts would be better because it isnt going outside of the actual model. Maybe I'm wrong.

You're right! 😄 Exclusive means that the print will be at most the size of the model file (basically makes it round down all calculations for "should there be a bit here").

 

You just need to be careful because if your lines (especially the minimum width) are too wide it can take more than you'd expect off. Whenever I'm printing pieces designed to fit together I always do test prints of just the connectors (small scale testing is your friend).