This is my attempt at making a case for my orange pi zero 3. I had printed the case at https://www.printables.com/model/542569-orange-pi-zero-3-case but I didn't like the supports that were required in the tiny holes. I also didn't really love the antenna holder design as it was a bit hard to remove the antenna. Finally, it didn't fully expose the USB pins. So, I designed my own case in fusion 360 with some inspiration from that design. After 6 iterations, I arrived at this design. I have sliced both with 0.3 first layer heights and .2 layer heights. You MUST slice these models with a .2 millimeter layer height or the support free part won't work. I used PLA, but if your chip gets really hot you might want PETG or ABS/ASA. I dont know if you can go bigger than 0.4mm - The hexagon pattern has 0.8mm walls, so I see no reason why it couldn't go up to 0.8mm. I have not tested that though.