LED Stars

Hello everyone! 👋  I'm signing up for this competition with a small project designed to attract your attention (if it really can do that 😆 to adults, rather to children), like the stars in the sky. This project that I named "My Galaxy" (somehow related to the stars that shine, but with LEDs instead) is the result of some attempts that date back some time, but I will talk about it during the presentation. In short, the list of components is something like this: - 1 card with ATMega8AU-TH; - 4 rings with WS2812B LEDs; - 1 IR detector module; - 1 push button; - 1 power switch; - 1 DC jack; - 5V power supply. I no longer count hand tools, soldering iron or wires. For some time I wanted to make simple board versions with ATMega uC, even if I don't make them in small sizes like the Arduino Nano, I wanted to have a board containing only uC and pin headers. Why? Because I need to have quantity, and the constructions are advantageous to me. As the HW and SW part is not the subject of this contest, I am moving to 3D printing. The model in which the rings are placed is inspired, but I like their placement, and since it was not easy for me to make this model for the rings using cardboard or something similar, I said to try something 3D printed. I have no knowledge at all, so I checked YouTube (😆) and chose Tinkercad, I work online, and for simpler things it's enough. I use many individual shapes, which I later combine into a single piece. I found a 3D printer in town, very good so far. But, with all my enthusiasm, I started with many mistakes, until I made this 3D these piece, I had 3 attempts, and I made mistakes like either not leaving more generous tolerances to fit the pieces, or thicknesses, or because of the white material something happens and the piece had spots, something brown like a burn (you can also see it on the last piece). Then I thought about how thick the piece should be in the area where the LEDs light up, and in the end I have 1.2mm, I have to give the piece