How to fix this STL

[baldengineer]

Occasionally I run across a STL that S3D slices a bit funny. This model is a good example. It is a plate for an Arduino with raised mounting holes, via Thingiverse. While visually a solid, the mounting holes slice with "bridges." Here's a screen shot showing the difference.



When I load the STL into MeshMixer, I can orbit the model and see there is a thin line between the hole's extrusion and the model base.



I don't know how to "fix" this model so that S3D see it as continuous. Anyone have some tips on what to do with a STL like this one?

[wirlybird]

Just a long shot here if I am seeing things right. Try going to the Mesh menu and select separate connected surfaces (I think that is what it is called) and see if that does anything.

[MasterFX]

Jup helps in this case. Just tried it

[baldengineer]

Jup helps in this case. Just tried it

What is Jup?

[baldengineer]

Jup helps in this case. Just tried it

What is Jup?

Anyone know what "Jup" is? Or another way to "fix" this STL?

[dkightley]

The stl doesn't really need "fixing", as there's nothing actually wrong with it!

What you're seeing here is a model that has more than one mesh within a single stl file.....something that is quite common when something is designed using low end CAD packages. Its not a bug or deficiency in the CAD package.....its just the end result of creating a shape from one or more shapes that are interleaved....or overlapped into each other.

Now, mid range to high level CAD packages have a reliable way of merging these multiple shapes into a single shape....called Boolean addition. Low end packages will probably have this feature....but like the package I use, the Boolean function can be a bit flaky and has a tendency to trash the shape at the same time! I leave shapes as multiple meshes and use the "Separate Connected Surfaces" feature in S3D to break the stl up into several stls....which S3D will slice perfectly.

If you do have a burning desire to amalgamate these separate meshes into a single mesh before loading into S3D then pass the shape through one of the online mesh repair services...and the meshes will be combined.

And as for "Jup"! Try saying it out aloud.....but pretend you're a Russian spy with a terrible accent!

[MasterFX]

Jup helps in this case. Just tried it

What is Jup?

Anyone know what "Jup" is? Or another way to "fix" this STL?

I should have write "... this [separate connected surfaces] helps in this case.
Jup = Yeah = Yes, meaning seperate conencted surfaces is the way to go.
Sorry for my german slang word.
The problem with OpenSCAD is, that it is based on combining and subtract bodies from each other, which can cause multiple bodies in one STL when you export them. S3D handles them different than most other slicers do. To fix that you can use "separate connected surfaces" and after that you can slice them.
For most models you can also use "3D Builder" which comes with Windows 10. (just open => Repair => save).

[baldengineer]

Thank you. Somehow I missed the mesh tools in the menu bar.