For just about as long as there have been electronics, there’s been a search for a way to let students and hobbyists build projects without a lot of effort. A board with Fahnestock clips was probably the first attempt. Today, it is more often the ubiquitous solderless breadboard. In between, we’ve seen copper pipe pieces and rubber bands, components mounted on magnets that hold them and make connections, and other even less probable schemes. A few years back, a new method appeared: Snap Circuits. The name almost says it all. A baseboard has mounting holes for different components. All the components make their electrical connections and mechanical connections through a common snap like you might find on clothing. Even the wires are little segments with snaps at both ends.
One problem with any system like this is how to integrate custom components. Of course, with the snaps, that’s not very hard, but [Chuck Hellebuyck] got creative with TinkerCad and worked out how to 3D print custom modules for the system. You can see his video, below.
The system uses 12mm snaps, and although [Chuck] doesn’t do it, you could probably 3D print your own baseboard, too, and not use any original Snap Circuit equipment if you wanted to do so. He did have to doctor the snaps to be double-sided using a grinding wheel, but otherwise it was fairly straightforward. He marked the component markings with a Sharpie, but we might have embossed or engraved the symbols and designator right into the plastic.
You might not be interested in using Snap Circuits, but it does make a nice practical example of using TinkerCad to build a part that mates with something that already exists. You can find the end result files on Thingiverse.