after failing to print the original nexus 7 stand several times, because of problems with the thin outside walls and top, I decided to use openscad to make them thicker. rename the original stl file to nexus7.stl and set the desired thickness in the openscad file. note that with my version of openscad and reasonably fast computer, rendering it takes about 20 minutes. I still had some minor problems printing it, but this may just be due to a bug in the slicing software that I use (slic3r).