@user21 Are you planning on replying to the guitar question? mathematica.stackexchange.com/questions/57326/… ?

@Öskå, no I don't think so, this would requite some more time, I'd rather not invest. What I have shown works in principal.

@user21 Importing the stl file and mesh it (and all what needs to be done) would nice to have though. I have no idea how one could mesh a stl file in Mathematica. The rest of course would be the same as the first answer.