Mechanical Computer: Pulley Logic Gates

thingiverse

Computers are incredibly complex machines that seem daunting at first to understand, but that's exactly why we're working on the mechanical computer project: to break down these complex ideas into tangible, easy-to-understand physical models and educate people so they don't feel like they're dealing with witchcraft. The technology behind computers should be achievable, not mystical. The first part of this project, Pulley Logic Gates, is directly inspired by an awesome video that introduced me to the idea. The premise is simple: using 3 rings as 2 outputs and one input, we can simulate logic gates utilizing weights attached via string as our "computer." It's a fascinating concept that has sparked my interest. Our assembled model will consist of a stand, a backboard, exactly 21 snap-in hooks, 3 rings, and 4 weights of varying sizes. This model is fully printable, except for some string needed for the pulleys to function properly. Print Settings Printer Brand: RepRap Printer: Prusa i3 Rafts: No Supports: No Resolution: .2 mm Infill: 50%-70% for the weights and rings, 20% for everything else Notes: The weights file has all the required weights in it. The individual files are provided for your convenience. The ring and hook files will need to be duplicated by your 3D printing software, with 3 sheets of 7 hooks working out pretty well. How I Designed This I used Blender, a fantastic free and open-source complete 3D CGI and modeling package, to design all the models. Largely basing the placement of hooks and weights in the system off of the aforementioned awesome video, the real task in designing this object was creating the stand to hold it up and the snap-in hooks for easy printability without supports. Designing a snap-fit system was actually pretty interesting and, with this being my first time designing a 3D printable object, a bit of a challenge. I utilized the boolean subtract modifier a lot in this design, and also got to apply some of the interesting calculations about this exact subject from an incredibly helpful website. But that didn't mean I got it right on my first try. On the contrary... Let's just say I went through a lot of iterations. Custom Section Project: Mechanical Computer, Pulley Logic Gates Project Name: Mechanical Computer: Pulley Logic Gates Overview & Background: Completing this project would give me a greater understanding of designing 3D printable models, something I had never done before, particularly with utilizing a useful technique of designing snap-fit parts. Also, learning to design a project to be completed by students to actually learn something is very new to me as well, because I'm a high school student myself. Objective: Students would be expected to learn more about the interworkings of logic gates, not only what each logic gate represents but also a little about how they work and are implemented in computers. Audiences This project is very scalable as it can be used as a demonstration in introductory 9th or 10th grade courses, but also as a project for more advanced 11th and 12th grade students, due to some of the logic gates being pretty tricky to figure out on your own. Subjects: This project could be used in high school computer science or engineering classes, as figuring out the correct setup for weights and strings is not only educational about computer science topics but also a brain teaser that encourages logical thinking, so it could be used in a wide variety of engineering classes as well. Skills Learned Students can learn critical and logical thinking skills through creating the pulley systems themselves or get a visual aid in understanding the logic gates through seeing the systems in action. Activity: Students can work in groups or independently and be given the necessary 3D printed materials as well as the goal of replicating the following logic gates: NOT NAND AND OR XOR NOR XNOR They would then use graph paper to plan out and design their logic gate while prototyping with the weights and pulleys along the way. The teacher would go to each group and offer help or sign off on completed and correct logic gates. Duration: The project could be anywhere from a 20-minute class demonstration done by the teacher, to a 2-period group project where the students need to puzzle out how to recreate each logic gate. Preparation: The only required materials are the 3D printed models, and lots of string. Students who are doing the activity as a project should have an understanding of what each logic gate means, though the project can also be used to present that information as a demonstration.