STL Repair Help

[tjans 0]

Hey folks! I am pretty new to 3D printing and having a blast! I printed a few things from Thingiverse and decided I wanted to try modifying something:

Thus, I took this STL:

http://www.sweethoss.com/files/sm-tactical.stl

Split it apart using NetFabb:

http://www.sweethoss.com/files/sm-tactical-without-base.stl

Used some union/translate code in OpenSCAD to make the base wider and taller and merge together. However, when I tried to print it, the base was partially round (on the right side) and straight (on the left side) so it wasn't printing in a complete circle.

I ended up cancelling the print and loading it back up in Cura, and sure enough the shadow that Cura shows doesn't look rounded either. Can anyone help me in repairing this STL? Tips on splitting joining using less tools would be awesome as well, but I felt comfortable with the NetFabb to OpenSCAD to Cura combo. The final STL is below:

http://www.sweethoss.com/files/sm-tactical-newbase.stl

[rowiac 53]

My first reply disappeared after I hit "Post Reply" so here we go again. Hopefully I won't end up with duplicate posts.

If I understand your problem correctly, I think the issue is that the STL file is not oriented so that the base is perfectly flat on the build plate. When I opened your file, I saw that there is small angle between the model base and horizontal.

To correct this you can try the "Lay Flat" function in Cura, which will rotate the model so that the nearest flat surface lays on the build plate. Or, you can reorient the model in another tool prior to importing it into Cura.

Personally I prefer Meshmixer for editing STL files. You can rotate the model by the exact amount for the base to be flat by using the Edit/Align function and playing around with the various options. In this case, the "surface scribble" option will work to select the bottom surface of the base as the surface to orient to.

You could also have used Meshmixer to add or remove the base instead of the NetFabb/OpenSCAD combo you used. To add a base I would add a cylinder primitive and adjust it to the proper size for the base, then I would merge the model and base together prior to exporting as a new STL.