For our recent midterm project, we took on the challenge of creating a functional 3D mechanical model using only 2D design and fabrication methods, such as vinyl cutting, laser cutting, and water jet cutting. I was fortunate to work alongside two talented classmates, Josefina and Alejandra, as we crafted a unique model inspired by our connection to Houston—the home of NASA. Our goal was to design a rotating model of an astronaut standing on the moon with a rocket orbiting around it, all powered by a hand crank with dual gear systems.
Our Inspiration and Concept
With NASA practically in our backyard, the moon landing became our natural inspiration. We envisioned a scene of an astronaut proudly planting both the American and Argentinian flags on the moon, with a rocket smoothly orbiting around him. To bring this idea to life, we realized we’d need a dual gear system: one set of gears for the moon and astronaut, and another for the rocket. We also decided that we wanted our moon to move in the opposite direction of our rocket, so the gear system required two gears for the rocket, and three gears for the moon. This meant designing a two-tiered setup to house both gear systems beneath the surface of our model, providing the rotational motion that brought our concept to life.
From Concept to Digital Design
Once we had settled on our theme and basic mechanics, we got to work on the digital side of things. Using Adobe Illustrator and several CAD tools, we developed multiple drawings and layouts. A gear generator website helped us customize the specific gears we needed, ensuring they would work smoothly within the structure. Every detail had to be mapped out digitally before we could begin prototyping, so we invested time and precision in these early stages.
Testing the Prototype
After finalizing our designs, we used cardboard for our initial prototype, cutting out the base and moon with a laser cutter to test for size. The first version turned out to be larger than we anticipated, so we adjusted it to a more manageable scale. However, a hiccup came along when a fire incident temporarily closed the laser cutter. Without access, we had to pause our cardboard prototyping phase and move straight into working with high-integrity materials.
Facing Challenges with Scale and Fit
Scaling issues became one of our biggest challenges once the laser cutter was operational again. When we finally cut our pieces, some were either too large or small due to measurement misalignments. This setback required multiple re-cuts and forced us to think carefully about efficiency and design accuracy. After several rounds of adjustments and cutting, we finally had a rough version of our model, which allowed us to confirm that everything worked mechanically.
Polishing the Final Design
With a working model in hand, we went back to the laser cutter to create a cleaner, polished version of our mechanism. We also incorporated additional elements as required by the assignment, such as a custom name tag, the flag using a vinyl cutter and a metal piece using the water jet cutter to enhance the model’s mechanical motion. This time around, we took extra care with assembly, ensuring every part fit perfectly before moving on to the next.
Reflections on the Project
Completing our midterm project was immensely satisfying. From conceptualizing the rotating astronaut and rocket to overcoming technical setbacks, each step brought new learning experiences. By taking our time in the final assembly, we created a refined and well-functioning 3D model that showcased both our skills and our connection to Houston’s space legacy.
| Cost Type | Cost | Price | Source | Quantity | Total |
| Materials | 2’x4’x3/16” Board (Gears, base, etc) | $ 12.89 | Home Depot | 1 | $ 12.89 |
| Vinyl Sticker Roll (Flag) | $ 5.99 per roll | Joann.com | 1 | $ 5.99 | |
| Aluminum (Handle) | $ 23.99 | Amazon.com | 1/6 | $ 4.00 | |
| Wood Glue | $ 3.97 | Home Depot | 1/10 | $ 0.40 | |
| Epoxy | $ 7.48 | Home Depot | 1/10 | $ 0.75 | |
| Superglue | $ 4.67 per two | Home Depot | 1 | $ 2.33 | |
| Wood Dowel | $ 1.26 | Home Depot | 1 | $ 1.26 | |
| Labor | Workshop Operator | $ 15.00 /hr | Ziprecruiter.com | 1 x 2 hrs | $ 30.00 |
| Prototyping Engineer (You!) | $ 12.00 /hr | 3 x 4 hrs | $ 144.00 | ||
| Overhead | Facility Cost (Machine Time) | $ 80.00 /hr | Practicalmachinist.com | 4 hrs | $ 320.00 |
| Quality Control (part replacement/maintenance) | $ 2000+ | Sendcutsend.com | – | – | |
| Design | Engineering and Development | $ 30.00 /hr | Ziprecruiter.com | 3 x 1 hr | $ 90.00 |
| Iterations | $ 12.89 per iteration | Based on extra wood used | 2 | $ 25.78 |
Cost Analysis
Cost Per Mechanism: $ 606.62
This cost is determined excluding overhead because if this item were to be mass produced the cost of overhead per item would come at a small fee. I also used our own labor costs which would make the item cost more since it most likely took my group and I longer than someone who is highly experienced in this field. On the other hand my charge per hour would be less since the quality probably wouldn’t be as good as an experienced woodshop operator. If a skilled worker were to have done this, they could have done it solo and probably in half the time, therefore labor costs, facility costs, and engineering/development would be cut down to $30.00, $160.00, and $30.00 respectively. Additionally, there would likely be no iterations. In this case the product would only amount to: $ 246.63
