There are some projects you work on that you do a little bit and set aside for a year or two before returning to, sometimes never finishing up. This project is one of those but it is one of my first core electronics projects and it has given me multiple skill sets that I used in plenty of my future creations.
I found the idea online on hackaday.com an analog “Equinox Clock” built of 60 LEDs in a ring that could light up (or create negative space) for the hands on the clock. The challenge of the project was lighting up so many LEDs easily. Before learning about neopixels and LED strips that are easily addressable I focused on shift registers. On a testing breadboard I setup the full clock with 60 LEDs and 8 shift registers. This let me do a proof of concept with some basic code for a second "hand" cycling through lighting up each LED in second intervals.
From there I worked on the design of the light. Not wanting to wait on ordering circuit boards overseas I began research on etching them myself. The steps are pretty simple. You start with designing the circuit you want. I decided to make 8 circuit boards, 1 for each shift registers, and 60 tiny boards for individual LEDs so I can better arrange them as a circle in the housing. I picked a circuit design software which had basic templates of integrated circuits patterns so I didn't need to worry about individual pin spacings as I laid down the pieces. After the circuit was designed I printed mirrored patterns of them onto transparent (overhead projector) sheets. Those sheets were laid down on top of presensitized copper boards. These boards are made up of the core wafer material with a coating of copper on top of that and on top of the copper is a layer of light sensitive material. When the transparent circuit pattern was laid on top of the board and exposed UV light the negative parts of the photoresist material burned away. Those parts were exposed copper so when they were dunked in an acid bath the negative parts of the circuit board burned away leaving the desired circuit. A quick rinse in neutralizer to stop the acid burning and I had a solid circuit board. The final step of manufacturing was to drill the holes for the components to pass through. The circuit software designed the circuit copper paths to have holes in it so the process was an easy one.
With the circuit board the next step was the solder everything together. I used connectors between each of the shift registers that were daisy chained together and with each of those boards to the individual LEDs so crimping those wires together were also done.
This is where my progress has stopped. I had a completed clock but no housing to put it in. With further discovery of LED strips I would start this project from the beginning and have a much easier build process to complete the clock but with the steps I took I learned tons of new electronic, coding, and design tricks that have I used in many of the later projects I've completed.