Random solid layer in the middle of my print

[Navig 0]

Hi all!

 

I am printing a bracket to attach to the end of 2x4 dimensional lumber.

 

 

 

 

 

 

The Slicer (v5.6.0) seems to be adding a horizontal layer, spanning across thru-hole for the 2x4.  I'm thinking it might have to do with the "top layer" being generated at the surface of the

countersinking for the screw holes on the wings, but I'm not very advanced in my 3d printing foo.

 

 

The solid yellow rectangle in the middle--I want gone!

 

I sliced it on the Bambu slicer, and it had no problems.  But this printer (Elegoo Neptune Pro 4) is set up and nicely tuned for printing PETG.

 

Thanks!

EN4PRO_End bracket surface mount1.3mf

[Slashee_the_Cow 620]

Your model file is invalid:

The areas highlighted in orange have their normals flipped - essentially they're pointing to inside of the model rather than the outside. That's why Cura thinks the top of those sloped bits need support:

And also if I lift it into the air it Cura doesn't think the bottom faces need support, because the bottom faces aren't actually pointing downwards:

So why is the bit it adds at the height it is?

It corresponds with the skin layers for the holes in the angled parts, which are the first faces actually pointed up, so Cura is probably assuming that that's the bottom:

So why is it actually adding it?

...that part I'm not sure I can answer. It could be that it sees the inside walls but since it doesn't think they have a bottom it's filling them in.

 

So how do I fix it?

There are online STL repair tools, or programs that can do it, but in this case the problem is minor enough that you can fix it in Cura, with a little assistance from the almighty @ahoeben. Go to the Marketplace at the top right and find and install the "Mesh Tools" plugin:

It'll prompt you to restart Cura to finish installing the plugin, so after restarting load your model, right click and select Mesh Tools > Fix model normals:

Voila! No more support required on the top of the angled bits which are actually pointed downwards:

Oh, and it also slices fine:

[Navig 0]

Thank you so much for the super informative and helpful reply.  And speedy!

 

It is pretty obvious that I have no formal education or training in 3d design.  I little bit of google education normals and flipped, and Sketchup--it is obvious from my initial uploaded picture that the surfaces have their normals flipped.

 

Selected the faces-->right click-->Reverse faces

 

And now they are appropriate!

 

 

 

Printed:

 

 

 

And mounted: Putting together a PT frame for my little solar array:

 

 

 

 

Thank you so much!

 

Also: interestingly, now I am having some issues installing the plugin.  I go to the marketplace, hit the install button for Mesh Tools.  I get a spinning wheel for a while, then nothing happens.  The spinning wheel goes away.  Maybe because it is Elegoo Cura?

 

 

 

[Slashee_the_Cow 620]

4 hours ago, Navig said:

Also: interestingly, now I am having some issues installing the plugin.  I go to the marketplace, hit the install button for Mesh Tools.  I get a spinning wheel for a while, then nothing happens.  The spinning wheel goes away.  Maybe because it is Elegoo Cura?

That would definitely be my guess. I know Elegoo Cura is a bit messed up in the way it uses its configuration folder (the fun part is that it uses the same folder as regular Cura and the two are incompatible) which is where plugins are stored.

 

4 hours ago, Navig said:

It is pretty obvious that I have no formal education or training in 3d design.

We all gotta start somewhere 🙂

 

4 hours ago, Navig said:

Sketchup--it is obvious from my initial uploaded picture that the surfaces have their normals flipped.

Sketchup is pretty notorious for making broken STL files. With something this simple there aren't too many things that can go wrong (yet it managed) but some complicated stuff I've seen has been next to impossible to fix.