Sketch Model Challenge
A list of the Functional Requirements we gave ourselves:
1. Price: Should cost less than $100
2. Weight of device: Should weight less than 40 kg
3. Weight limit: Should hold at least 80 kg
4. Radius: Turning radius of 5ft.
5. Environment: Should function in Chicago environmental conditions (including snow and rain)
6. Life expectancy: Should last at least seven rounds of dodgeball
7. Extra: Should have at least one safety feature
We considered vehicles such as a sled, chariot, hamster wheel and tank.
Design Process & Analysis:
Once the finalized design was created, the team proceeded to purchase the materials and make the necessary cuts in order to create the wheels and holes for our axle. The wheels were made wider to reduce the pressure placed at those points in case of snow. Unlike snow tires which are commonly thinner to apply more pressure on the snow and dig through to reach hard ground and have better traction. The cardboard tubes used for the axle were first tested to see if a lot of bending would occur. Axle bending would make the wheels angled with the ground and cause a lot of resistance. The friction between the wheels and the spacers/cardboard seat was further reduced by gluing wax paper to the wheels.
An effort was made to 3D scan the components and perform analyses for stress concentration. Unfortunately, the scans were imprecise and not needed to move forward in our process. Nevertheless, it was a good practice to continue when working with more complex parts in the future
A series of pictures showing the progress leading up to the final product
Brainstorming & 3 Needs:
Each member generated 20 drawings for various needs. These included ideas ranging from combination kitchen appliances, to home improvements tools, and even some that were plain outrageous. Once all ideas had been presented. The group discussed the merits of each and concluded to move on to 3 ideas for our 3 needs presentation.
1 - Microwave Stirrer
2 - Turtle Tank
3 - Adjustable Paint Brush Cleaner (PBC)
Sketch Model - Turtle Tank
The team created a critical function model to serve as an upgrade past the sketch model to show how our product would actually work. We committed towards pursuing the paintbrush cleaner. After receiving feedback from experienced art employees, a rotating spring coil was implemented to the design. The coil would be rotated by a spring gear motor; and sponges were attached to dry the brush after the cleaning process
The team decided to create sketch models for the turtle tank and PBC.
The turtle tank sketch model involved a two-part system. The tank was fabricated using cardboard materials and included features such as a heat lamp, filter, and stocking shelf for the turtle. The second was a draining mechanism that was 3D printed that
Sketch Model - Paintbrush
The final product is an upgrade from the critical function model where a housing made of PLA is used that encases a majority of the components. The idea is to have the user only see the paintbrush go in and make the contact with the spring. A toggle switch is incorporated to make the user have the capability to turn on and off the machine. For more details see the alpha prototype page.