[Roboshant]

I don't know how good of an idea this is for a 3d printed plastic part but: Make a hole in the 3d printed part from one side that is the size of the outside of a nut that matches the size you need (in the CAD file of the part itself), or just make a circular hole the size of the diameter of the nut. After this is done secure it in place using epoxy or other methods (3d print over it lol). This would mimic tapping it, although I have absolutely no Idea how well it would work (might be worth trying). I now this is completely anecdotal evidence but, I did this on a wood part for a non-FRC related project and it seemed to hold up pretty good. Good luck!