3D Letters losing shape when exported

[hampie42 0]

Can someone help a noob. Have created 3D text in Sketchup and all looks great, but when I export the .obj file it seems to have lost curve data or something and has strange added vectors that ruin the whole thing. Pictures explain it best. I'm sure this is something simple but here I am on a forum asking for help. Be gentle.

[peggyb 171]

In SketchUp you have to be careful with the direction of your surfaces, what you see here is that there are some surfaces 'inside out', facing the wrong way, making your model 'not watertight'. Imagine folding a cube with double sided coloured paper, one colour faces outside, the other inside, yours has some mixed up. When you export your model, the software tries to connect all outsides and when some of them are facing the wrong way you get this weird vectors.

I am not a SketchUp user so search for this to get it right, there are also export plugins to detect problems.

[hampie42 0]

Thanks PeggyP this sounds very likely to be the issue. I've got something to go on, if I find an answer elsewhere I'll post it here.

[kmanstudios 1,120]

I am not a sketchup user for a variety of reasons, but from what I have read on these forums, there is something to fix it. Searching the forums would be a good start as I see it posted a lot. I just do not pay attention as I do not use it. Maybe someone who deals with this can make a post and shortcut your process.

The reasons Peggy named are spot on though.

[eldrick 65]

Sketchup generally does a miserable job of exporting .stl files.  

For 3D printing, you would be better advised to choose another graphic program, IMHO.

For this particular job, tinkercad.com would be a good choice.

Edited July 30, 2017 by Guest

[ahoeben 1,956]

Strictly speaking the faces being inside-out does not matter for Cura. Cura uses the "normals" of faces to display overhang (the red parts in Normal view), but they are not used for slicing. What does throw off Cura is models that have holes in them (even if these holes are super tiny), or models that have "internal geometry". The latter is when you have eg two adjoining cubes that have a face between them.

Sometimes you can try to let CuraEngine fix the problems during slicing with "mesh fixes". If you go into the "Settings Visibility" pane of the preferences you will see a whole category of fixes. Make them all visible, and then try changing each option in the sidebar.

The best tip of all remains: don't use Skecthup for 3d printing.

Edited July 30, 2017 by Guest

[geert_2 558]

You can import SketchUp files (skp-files or something, not STL or OBJ) directly into the freeware 3D-editor DesignSpark Mechanical ("DSM").

If you do that with fonts created in SketchUp (with the characters as vectors only, or as surfaces, not yet 3D-models) and then you try to make 3D-models out of them in DSM, you will see that in a lot of characters the vectors-ends do not match: there are tiny gaps. It are not closed shapes. In DesignSpark Mechanical this can be repaired manually by zooming in on the offending characters and vector-ends, and manually adding small vectors to close the gaps. Then these characters can be "3-Dimensionalised" as expected. But sometimes this does not work well.

The same happens with walls and other design parts in SketchUp.

I guess that if SketchUp makes an STL- or OBJ-file out of its defective vector- or surface-elements, that STL- or OBJ-file also contains these defects. Which is guaranteed to cause problems in 3D-printing.

I am not sure if you can repair those defects in SketchUp itself in the source files.

It would be better to do the design in DSM (or another editor) that is designed for solid 3D-modeling and printing.

As far as I understood, SketchUp was never designed for solid (watertight) 3D-modeling: it was only meant to create superficial 3D-looking models to represent buildings in Google Earth and Maps. In which case gaps in the models don't matter at all, as they are only needed for crude visual representations on-screen.

But now Google has developed another way to turn its photos directly into 3D-models, so it didn't need SketchUp anymore and sold it.

For example, in Google Maps in your browser, if you zoom in to the port of Antwerp (Belgium, Europe), and then use the Control-key and mouse buttons, you can rotate and fly around in the 3D-world. The 3D-effect is not perfect, but still impressive and fairly accurate. Similarly, you can also fly through the mountains in the Alps in 3D.

[Brulti 177]

As the others said, Sketchup is quite bad for 3D printing.

I've personally used Blender to create letters and I was able to print them on my UM3E without any problem.

I could make your letters if you wish, it's easy for me in Blender. Or you can also download Blender (it's free) and try yourself! ^^ Though there's quite a learning curve in Blender, as much as there is in 3D printing I'd say.