MECHANICAL SPIROGRAPH
The mechanical spirograph is a mechanical version of the beloved children's toy, powered by different size and positioned gears to create fun and vibrant patterns. This spirograph allows for different gears to be exchanged into the acrylic base to create a variety of patterns and shapes.
Final Design
Ideation Sketches
To tackle this project, I first did a lot of research on how the original, non mechanical spirographs work. I decided that, with the scope and the time allotted for the project, it would not be possible to create as many variety of shapes as the original spirographs, but I did want to create more than one pattern design with my spirograph.
I broke up the spirograph into 3 separate components, in order to conceptualize what I needed to do in order to create a functioning spirograph. The three components were 1. base,
2. gear mechanism, 3. pen holder/slider. To tackle the base, I decided to laser cut a 9in by 5.5in, 0.25in thick clear acrylic sheet. I would use heat inserts into the base to hold the gears. The gears and pen holder would also be made from acrylic to minimize friction. I had lots of ideas on how the spirograph would function, but these were modified as the design process progressed.
Prototypes
For my initial prototype, I wanted to create the basic form of my spirograph to see how the different parts would work together. For my initial design, I made my on gears in SolidWorks, but for later iterations of my project, I used our professors gear template. From this initial design, I knew I wanted the placement of the smaller gears to be interchangeable, and the toggles connecting the pen, to be able to slide up and down the side panel depending on which gear was creating the design. I also realized with the shoulder screw sticking out of my gear, for my final prototype I would need to have a flat circle on top of my gear to create a surface for drawing the spirograph on.
For my second full(ish) scale prototype, I screwed in the 3D printed toggles, and had a semi functioning pen holder (I had not yet laser cut my final design for the pen holder). For my final iteration of my design, I needed to create acrylic washers to create more stable movement of my gears, create a platform above my center gear where I could place my paper, and modify my pen holder to the final design. Although it was not a robust design, this prototype functioned on a basic level, but was not strong, and had some issues that needed to be addressed.
Iterations of Components
Pen Holder
​
It took several iterations of the pen holder mechanism to get it right. At first, my middle hole was too big compared to the overall size of the part, so it was very unstable and weak. For the next iteration, I increased the overall width of the piece to make it stronger. However, I did not take into account that a screw would need to fit through the piece, and I made the hole too big in comparison.
Gears
At my beginning prototyping phases, I was focused on making the gears move smoothly, so I could create a fluid spirograph design. I talked to the TA, and he gave me the idea of having larger acrylic “washers” underneath my moving gears to help minimize the wobble, especially since my large gear was 5in in diameter. These worked well initially until I realized that I needed to put a screw through my smaller gear to attach my handle and through my larger gear to attach an acrylic plate to create an even surface to create my design on.
For my final iteration of the pen holder, I made space for heat inserts to connect the two pieces that hold the pen, then a separate space for the pen holder to slide along the toggle. This design worked a lot better because the heat inserts were much sturdier and were able to hold the pen in place much easier than previous iterations.
I realized then, that the initial holes I drilled through my gears were too large to place the size screw I wanted into the handle, so I had to re-laser cut my gears with holes to accommodate a 6-32 size hole. For both my smaller and large gears I had to recut my acrylic “washers” such that they would not interfere with these screws coming through the base. The images are my initial prototypes of my smaller gears and acrylic “washers”.
Digital Files
Reflection
Through this project, I learned how important making sure your dimensions are right, and taking the time to double (even triple) check everything in SolidWorks before your laser cut or 3D print anything. Although I did make some mistakes of my digital modeling that cost me time, most of the time I spent on this project was attempting an idea for my design, it failing, and then me re-designing to fix the problem. However, the failures I encountered in my project, made for a better final product, which I am very proud of. The only thing I would do differently is make my assembly in SolidWorks before I created it in real life. This would help minimize missed dimensions. Overall, I had a lot of fun throughout the process and I am proud how my final product turned out.