>>64330944
3d printing seems like the wrong tool for AA fire. Anything smaller than a rifle round isn't going to do much to a plane and you get into pressure concern territory with that.

For a targeting display the only thing I can think of would be some 3D printable attachment that combined a mini RADAR/rangefinder with a programmable sight/GOPRO screen overlay that tells you where you need to lead your shots to hit a plane. The whole thing would be an entire engineering project for something only slightly better than having a second or third dude spraying down a plane, though