The following designs are presented in reverse chronological order. Each provides a link to another page devoted to the specifics of that design. Later designs necessarily draw on learnings from earlier designs.
Version 4: Eliminating the need for breadboards.
Breadboards are bulky and expensive. In many cases they are overkill and provide many more options for connections than are necessary and, as such, provide many more opportunities for error. This version embeds as much of the circuit design as possible in the 3D model itself. It also introduces an alternative to soldering – injectable conductive paste. Finally, it eliminates the need for cutting wires to length and stripping away insulation; and uses a snap-on technique for assembly.
Version 3: Introducing the Flexure Spring.
This version introduces the concept of a 3D printed flexure spring instead of a 3D printed leaf spring. A flexure spring has one major advantage over the leaf spring (and any traditional metal coil spring, as well) in that it forces the center post of the switch to travel “almost” vertically. That means that it can ensure that the button or button collar doesn’t get caught under the edge of the switch cover. In addition, by making the cover hole a little larger than the button or button collar, it eliminates the problem of printed layers scraping against each other and leading to a smooth upward and downward movement of the activation surface without the requirement for Teflon tubing.
Version 2: Utilizing captured nuts and printed threads.
Rather than using threaded inserts that have to be heated and pressed into place with a soldering iron, this version looks at adding capture cages for standard (and much cheaper) hex nuts to the 3D model. It also used the Fusion 360 capability to model screw threads to create a 3D printable post to replace the large bolt. Unfortunately, the printed post still has a rough outer surface and has to be inserted into a Teflon tube in order to reduce friction. Even worse, the fact that the post is narrow and printed vertically, it can be broken along layer lines. This is particularly a problem where the post screws into the activation surface.
Version 1: The initial Volksswitch Design.
This first version of the Volksswitch of the Volksswitch meets all the requirements stated above – though the procedure for adding threaded inserts can be tricky. Primarily it introduces the use of mini-breadboards to simplify circuit assembly and eliminate the need for soldering skills. It also introduces the concept of a 3D printable and customizable leaf spring – eliminating the need to find commercial coil springs of just the right size and tension. Finally, the design includes two micro-switches and a “switch gang” so that a single press of the switch simultaneously closes both switches. Since the second micro-switch has its own associated battery, the additional micro-switch can activate other powered components like LEDs, buzzers, vibrators, etc.