I found about “useless machines” through a YouTube video. I could easily say what I felt for such machine that it was love at first sight, and immediately decided that I should make one. Below is a video, demonstrating my very own useless machine project.
I decided that I was not going to use any microcontroller for the realization of this machine only because I wanted to take this little circuit design project as a puzzle for myself to solve. Also later I could compare the circuit coming out of me with the others I could find online to see the differences in the engineering approach to the problem.
The box was made using a special box‑making technique where it was initially crafted in one piece as a totally sealed enclosure. The lids were cut out after the surfaces of the box are sanded down to level. Using such method, the lids fit to the rest of the box as flush as possible resulting in a much neater look for the box.
The box also includes two blocks of cast lead in order to increase the overall weight of the box to give it a rather more appealing feeling when handled. One of these blocks also help the main lid close down stronger making a snapping sound once the two faces of plywood hit together. I believe such effect contributes a lot to the user’s general feeling about the machine, making the device even ‘crankier.’
The circuitry was constructed on a perforated prototype board. As the actuator, I have used a servo motor which I already had a couple laying around. The two different signals to control this motor were generated using a timer (the epic 555) in combination with the two switches placed on the box. The first of these switches is a limit switch which basically checks whether the main lid is open or not. The second switch is the one resting on top of the box, which triggers the cranky machine to undo what the user has done. The first key feature of the circuit is that it yields zero power consumption as long as it is inactive, thus increasing the battery life dramatically. And the second is the accurate calculation and trimming of the passive component values so that the servo motor is not forced beyond limits of motion preventing its gears from excessive wear.
This is one of my favorite makes because it makes me feel like the machine actually has character. In this sense, it actually reminds me of Guy Hoffman’s “Robots with Soul” work, especially the “Robotic Desk Lamp” which happens to be one of my favorite human‑robot interaction projects considering that people using this lamp actually referred to the machine as a “He” or “She” rather than a dull “It” apparently having felt a closure to the machine. Well now, this is what I call an interaction!
Also letting aside its being practically useless, I think this is a truly inspirational machine and a great invention to carry on Marvin Minsky’s (rest in peace) legacy for generations to come appealing to anyone at any age.