In this project, we tasked to choose a mechanism, build low fidelity prototypes of the mechanism, and then use AutoCAD to design and laser cut a working high-fidelity prototype. The goals were to enhance understanding of mechanical motion and improve AutoCAD 2D modeling skills. The completed items from the project were a low fiedelity prototype, a high fiedelity prototype, and a technical AutoCAD drawing.
My low fidelity prototype features a cardboard disc mounted to a backing board, connected to a rigid arm by a pin joint. The opposite end of the cardboard arm features a slider block constrained to move within a linear track that is cut through the backing material. When the disk is rotated manually using the pin in the arm, the circular motion from the disk causes the slider block to translate back and forth along its track.
Using the successful low fidelity prototypes, we developed a 2D AutoCAD drawing that was sent to a laser printer and cut into a piece of 3.9mm cardboard. To make the AutoCAD drawing, I relied heavily on what was observed from the low fidelity prototypes. This led us to designing the high-fidelity prototype by cutting the linear path directly into the backing of the mechanism and using a pin to secure the arm to the block to the linear track in the back. When assembling this prototype, we added a wooden dowel on the pin that is used to spin the mechanism, making it easier to use.
Figure 1. This figure features the completed flow fidelity prototype.
Figure 2. This figure features the completed laser cut high Fidelity prototype.
Figure 3. This figure features our AutoCAD technical drawing. The figure is in a 1:1 scale and features all of the pieces of our prototype
IMG_1915.MOVIMG_1828.movMy engineering design process for this project was learning through trial and error. By starting with basic cardboard prototypes, I was able to quickly test my ideas and figure out how all the components interact without worrying about perfection. The sliding mechanism gave me the most trouble during the initial step. I tried different approaches before finally realizing that cutting the track directly into the backing board was the simplest and most effective solution. Also through trial and error, I was able to figure out what the most effective way to connect all the separate components was. When I moved to AutoCAD and laser cutting I ran into a new issue with the arm width causing binding at the center pin. The technical drawing forced me to think about the exact measurements to make all the components interact properly. This process involved a lot more iteration, and taught me to be ready to adapt and problem solve. Each 'failed attempt' taught me something new about the prototype, and eventually led me to creating a sucessful product.