Simply extruded solid does not mesh properly

Rhino
,
1

Test print
Test print1920Ă—1274 755 KB

This is a simply solid extruded from two closed planar curves. Why does this not mesh properly?

It is a valid polysurface, closed solid polysurface with 15 surfaces.

2

Hard to diagnose the problem without a file

3

Test print.3dm (232.3 KB)

4

Meshed as expected on the higher quality preset

image
image1696Ă—722 504 KB

To get the other one to behave better:

  • Ctrl+Shift Click on top surface to select one face of the polysurface
  • DupBorder to copy the edge
  • SimplifyCrv cleans up stray vertices
  • Once I extruded this solid, the meshing worked fine with all the settings I tried
5

Thank you.

Are you using Rhino 7?

I took the solid back to the original two planar curves. Used SimplifyCrv. Created surface. Extruded surface. Used mesh to preview. I do not see the same dialog box. Result did not change at the corners. Mesh is less refined than yours. Increasing the number of polygons had not real effect. Went to detailed options. Do not see the same dialog box you showed.

I do not generally work with meshes but using a new printer.

Am I missing a general setting in options?

Suggestions?

6

Hi 2849 -

Artstep’s screenshot shows Rhino 8.

In the ExtrudeSrf command, set SplitAtTangents=Yes.
Does that make a difference?
-wim

7

Yes, that got rid of the extraneous triangles. However, when saved at stl and imported into Bambu Studio, it found non-manifold edges that required fixing. It was able to repair them but that still indicates an issue. With Rhino 7??

8

Converting the object to a mesh with the Mesh command wil allow you to run Check on the mesh before exporting it.

I would not use STL, as it looses too much information. Bambu Studio with take 3MF or OBJ. Both of those formats are much better and less likely to create problems.

9

Thank you for your help.

I went back to just the two curves and just extruded them rather than first creating a surface. This was then saved as a stl and imported into Studio. It came in fine with no non-manifold edges.

When I first created the surface, this apparently caused the problems. Don’t know why.

Again, thank you to all that offered suggestions. Still a novice at Rhino, apparently.

10

Bambu Studio also imports .stp files.

There is a mesh density adjustment within Bambu as import the model.

11

_DivideAlongCrease splitattangent = yes
then
_mesh
Make sure to use detailed parameters and set edgde ratio …(or similar)

…will edit / correct / finetune this post back to my computer tomorrow…

Good night