Any ideas for 3d printing combined with Raspberry Pi projects for me to do with my kid?

I build a powerful, compact river tube motor but its brain is a 328p. 3d printing would have made for a much better design than my potted pipe.

Next doing an autonomous cooler but that’s on Nvidia. RPi might do it but need ai accelerator for vision and maybe limit lidar layers to 1-5 plus lower res and FPS.