Fixing 3D Designs

One of the things George warned us about is the possiblity that Mathematica might create an invalid .stl file when it exports. I don't understand the bug exactly, but somehow when it draws the .stl, which is composed of many triangles which have orientation, it might create some triangles either with orientation reversed, or with edges that don't align correctly. He suggested two tools to detect and fix these errors.

Since I had a problem printing my lissajous figure (see image below), I thought it might be from this sort of error. I downloaded and installed the first tool, VisCam, and it indeed found 24 flipped triangles. But this tool cannot fix. It can only check for errors. So I downloaded and installed the second tool, NetFabb. It took a while for me to figure this one out, but eventually I found the menu to check, and the menu to repair errors. But it wants to save only in its own format, and it took me a while to discover how to export back to .stl. Turns out the part has to be selected for this option to appear. Okay, obvious, but it took me a while.

Next week I'll try printing the repaired part, and I'll report back on how it goes.