I'm new to 3d printing and need to design and print a case on an Ultimaker S5 using PLA. The case is box like and consist of a top and a bottom part. I was thinking about cantilever snap-fits to join the two parts. I read that these snap-fits need to be printed in the X-Y-plane for better stability. However with the bottom/top side down the walls will be in the Z-axis and thus the snap-fits would be printed in the X-Z- plane. If I would print the part lying in it's side I would need a lot of support in the inside. How am I supposed to do this correctly?
Also what tolerances should I use to make the parts fit well while still being separable?