3D printing a model problems

Hello, I was asked to draw a model of a box to hold an arduino and other components for a friend. I sent them the STL file to print on their CubePro. The first of seven parts stopped in the middle of the print with a “filament error” ( I did not see the error but this is what I was told.) He claims to have tried printing it three times and it stopped in the same spot each time so he thinks it is the model. A friend of his looked at the STL and said it was a poorly built model, but I didn’t get any specifics as to what he thought the problem was. All of the pieces are closed polysurfaces. I ran the model through Slic3r and then printed it on my printer. It printed fine for me. Has anyone else had problems with the CubePro printer? Can anyone tell me/show me that there are errors from a poor build?

I will attach a file with four of the pieces. The part in red is just a bridge support piece.

Kevinbox v2 print file 2.3dm (1.2 MB)

That sounds like a error with the generated Gcode - was your friend also using Slic3r with the same settings as you? It’s also a good idea to check the toolpaths with a program like Repetier-Host before sending it off to the printer.

The model looks fine, one thing you could try is using _MergeAllFaces to join coplanar surfaces- maybe that will help with the meshing.

Hi Kevin - it does not look bad to me - the one thing that could be better is to make coplanar and ‘co-cylindric’ faces one face rather than a bunch - see the attached file - compare in wireftrame view to see the simplification - it may be that this will make a cleaner stl mesh as well. From your comment it seems the mesh file was faulty somehow, not necessarily the surface model
box v2 print file 2_PG.3dm (795.2 KB)


Hi Kevin,

there are errors in the model, i’ve highlighted where to look at:

Part A has a hole which i highlighted, there seems to be a missing trim in the outer wall. The top angled cut surface has a tolerance issue. Once you used _MergeAllFaces on the part, it turns into a bad object. To repair it, use _ExtractBadSrf, then delete the the surface i highlighted. Select all remaining surfaces and use _DupBorder, then _PlanarSrf , delete the curves and join everyting into a closed polysurface.

Part B has an inaccuracy at the bottom face and probably on the top face too. Switch to wireframe, then in front view zoom close to the bottom surfaces, they are not coplanar. Part B does not survive _MergeAllFaces so i would take a closer look at the top surfaces which fail to be merged.

Part C could be improved, use _MergeAllFaces here as suggested already above. Merge the vertical cylinders by extruding them in one piece.



small follow up to the round hole in part A. If this should not run through the outer wall, the wall thickness there is only 0.03mm. If i run this through Cura slicer, the wall to the outside is just ignored as it is way below the nozzle diameter.


Thank you for your input Clement. How do I go about finding tolerance issues within surfaces? If it tells me that the model is a closed polysurface, I thought that meant all edges are within tolerance settings.

Hi @Kevin_Johnson,

the issue on part A and B i’ve recognized first because Rhino complained after using _MergeAllFaces with this dialog:


If you do not get the dialog, you might have to enable _CheckNewObjects. The lower surface on part B i’ve just seen visually as merging the faces and creating one planar surface from the borders at the bottom did not work, so i zoomed in to find out why.

I have a script to visualize it. The trim edge tolerances where below the document absolute tolerance for part A (0.0003mm) before merging faces. But this is a high value for non freeform geometry. Problematic edges are in hotter colors:

Part B (before merging) had a max value of 0.0019mm, near the angeled round holes, there is nothing bad about it, as the STL was closed after exporting it:

Part C had 2 edges on the right side with low trim tolerance (0.0064mm) marked red in below image, but those got fixed by merging, so i did not mention them:

btw. it could be none of the problems listed above is the source for the print failjure. If you can post the STL or the settings used to export it, it would be interesting.

@clement I will attach the STL, the settings used to export it are whatever is default.
matt part 7.stl (1.7 MB)
I am unfamiliar with using scripts. Is there somewhere I can download a script to visualize the edge tolerances, or is that something you wrote?

I really appreciate your time and help in improving my model building.
Thank you

Hi @Kevin_Johnson, i have not published this yet but plan to rewrite it so it is easier to interpret the results it outputs. If i find some time soon…


No,they used the Cubepro slicer. Thanks for your suggestion.