Panel

The panel

Before starting to cut and drill the plexi glass for the panel, I suggest to get a case first, where the panel is supposed to be finally mounted.
This is to know exactly how big the plexi glass has to be cut to fit into the case.
I didn't do this and had to cut a bit off the plexi glass after the LEDs were already mounted and wired. It's doable but not funny, I can tell. ;-)

After cutting, I used an old-school ruler, a set square, and a pencil to draw the lines and markings for drilling the holes for the LEDs.

For drilling, I used a 5mm wood drill in a drill press machine.
I definitely recommend to use a drill press to get the holes straight, which won't be possible by using a standard pistol-grip drill.

Mounting the LEDs

I decided to do multiplexing with the six segments of the snowflake.
So for each segment I soldered the LED anodes together.
For the cathodes, I used wire pieces to make rings.
Finally, I soldered six thick wires for the anodes and 30 thin wires for the cathode rings
in order to connect the cathodes to the driver circuit and the anodes to the multiplexing circuit.

Doing this kind of wiring is a hell lot of work.
Since I like soldering stuff, it was quite fun for me.
But I have to admit that I'll do this differently (simpler) the next time. :-)