This is essentially a base for making more interesting boxes for things, in my a case for a dial indicator. I thought it would probably be useful for other people so here it is. It doesn't need any supports to print and wasn't designed with needing additional hardware in mind. It has a snap close latch that relies on the pliability of the plastic. I almost always print in PLA, so this aspect may differ/not work at all if you use something else. I've added a bunch of different random sizes to the files section, I'm not sure how useful that is really, but there you go. The f3d file is probably the important part. For what it's worth the minimum size that works is about 70W x 30H x 15D. These are probably the only parameters you would want to change, but I have explained some of the others too, in the parameter comments.

You can get the files over at https://www.printables.com/model/304757-parametric-case-with-clip-latch