Issues with converting to .stl and 3D printing

I’m not 100% sure if I am in the right place, but I figured I would start here. I am trying to create a small trophy to 3D print and am having a very hard time printing it. I am really lost as to what to do at this point. Here is what I have done:

Regular NURBS Model:

  • I attempted to convert it as a NURBS model to .stl (units in mm). It appeared that the mesh was just fine when I analyzed it in Simplify3D, but it consistently stops printing at approximately 5-7mm, only on this model.

Converted to Mesh Model: (Conversion after some research)

  1. ) First I converted my model from mm to inches. My assumption for issue #3 is that this might have caused it.
    2.) I attempted to convert to inches and then convert to mesh (from NURBS object). I made sure there were as many polygons as possible just to be safe.
    3.) When I analyzed the mesh in Simplify3D there was absolutely no infill within the model.

I’m pretty new at this and am figuring things out as I go along. I have not had any formal training on Rhino. I tried to research as much as possible prior to asking on here, but I’m a little loss now. I think my next step would probably be to redo the model, but start it in inches versus mm. Any help would be much appreciatedSMPC Trophy.3dm (7.6 MB)


in order for Simplify3D to be able to add infill to this model, it has to form a single closed volume. Your model is made of multiple volumes which touch each other. I´ve first deleted the meshes and worked with the polysurfaces. A single volume can be created by just using _BooleanUnion, at least generally. To make this work with your model, there should be a clear intersection between all polysurfaces, so i sligtly scaled the large flat base cylinder using _ScaleNU by a factor of 1.005 in xy directions, otherwise the text around the cylinder would not boolean as it just touches the cylinder.

You can now just save this in *.stl, once the dialog comes up, you can set the mesh density, which means your polysurface volume is converted in a mesh once saved. If you import this stl into Simplify3D, make sure to look at the print preview to check if the infill is inserted properly. Also make sure that option is enabled of course.

Model.3dm (5.7 MB)


Wow, thank you very much. I was going to contact an administrator to delete this post because it was too broad of a question. Originally I had it boolean union’ed, but I must have done something to break the union.

Your parts where grouped, that is not the same as unioning them :wink:

i hope it prints now, however, there are some things you might consider to avoid that unnecessary support material is printed. eg, the 5 rods above the cylinder might better be printed seperately, but upside down and later glued…but this is just a suggestion.


Yeah, I have been learning the hard way about support structures. I work for a math lab (undergrad) and everything we print usually requires some sort of support. Again, thanks for the help!