Never heared of Kevin Darrah, but that was solved easily enough:
The description of TT_Tech is a bit … lacking and I think OP meanes somthing else with:
With LED cubes, the LED’s are soldered together with their own legs, and not to a PCB. To make a LED cube look good the LED’s have to be soldered in straight rows and line up perfectly.
For an 888 cube you need 512 LEDs and for lining up all those LED’s nicely some kind of jig is needed.
On AliExpress / Ebay / China you can buy LED cube kits starting at around EUR20 for a monochome kit. Those kit’s are not all the same, and they usually do not give enough information to make a clear distinction between them.
About 2 years ago I bought such a kit, but never soldered it together. The PCB of my kit has a grid of 8*8 holes to align the LED’s. The idea is to put 64 LED’s in the holes, bend their pins and solder them together, then take the LED’s out of the holes and put the next layer of 64 LED’s in the holes for soldering.
This seems to work well for monochrome LED cubes.
If I were to make such a PCB in KiCad, I would simply use a grid of 8*8 mounting holes with the diameter of the LED bodies.
With RGB LED’s it is a bit more difficult though.
These have more legs to solder, and first making flat grids of 8*8 LED’s and then soldering the layer’s together does not work as neatly.
Some of the jigs Ive seen for RGB Led cubes are made out of laser cut acrylic, and even then are only for a column of 8 LED’s, but I have not looked much into RGB Led cube’s.
There are however plenty of tutorials for building LED cubes on Instructables and Youtube.
Controlling the LED’s is usually done by chaining together a bunch of shift registers such as 74HC595.
I find Kevin’s use of TO220 MOSfet’s (for the column drivers?) a bit strange. Small SOT23 MosFets can deliver 2A or more, and that should be enough for a bunch of LED’s I think.
Making a schematic in KiCad for a LED cube would not have all the LED’s in it.
All symbols drawn on the schematic need footprints and are imported into the PCB (Unless surpressed with # in the refdes. )
The most suitable schematic symbol for the LED’s are probably symbols for 8-pin connectors, for each row of LED’s.
Then in the Footprint Editor, use the “S-DIP” “Single/Dual Inline Package Footprint Wizard” to make a row of pads with the right spacing for the LED’s in the LED cube.