Built my own version of this 8x8x8 LED cube on a large prototype board. The soldering was rough, and for some reason, I split the ribbon cables into individual wires—so it was a bit of a mess. It lit up and I got some animations working, but the board was unstable (probably due to shorts or grounding issues). On the bright side, I built a working demultiplexer from ICs and finally understood how they work. If I ever revisit the project, I'll design a proper PCB in Eagle for a cleaner, more reliable build.