This past week, the design team consulted with Craig Milroy, the head of the Product Realization Lab. We communicated our design goals i.e.improving the enclosure design while minimizing unit cost to be able to quickly and efficiently produce thirty units for the summer. Craig recommended that we look into ordering online electronics enclosures that have already been manufactured and then post-machine them. This could be done using the manual mill or the CNC mill to create holes and cuts for wires, vents, screens, etc. We realized that we could use the manual mill for early prototyping, however the CNC would be optimal for manufacturability and precision. In addition, the CNC manufacturing could be easily outsourced once the design has been finalized.
He also recommended increasing out target goal of completed enclosures for the end of the quarter, for example from 30 units to 100 units, so as to further reduce the cost per unit by ordering the enclosures in bulk. This would have to be done after testing. In terms of materials, we learned that ABS plastic or aluminum would be our best options keeping in mind our goals for increased strength and durability of the enclosures without a significant increase in the material costs. Finally, with Craig’s direction, we realized that we should simplify our design to its necessary functionalities and remove showy and unnecessary components such as storage shelves or compartments. This will allow us to decrease cost to increase affordability and decrease size to increase portability and transportability to Zimbabwe.
In relation to the EE team’s touchscreen idea and required volume of necessary electronics, we will be working with an enclosure that is about double the size of the smaller compartment from our unpainted duron prototype from Fall Quarter (new dimensions 6” x 4” x 4”). Our next steps for this week include finalizing on a couple of enclosures in both aluminum and ABS based on the specified dimensions and required functionality, and order a few units of each to start testing out post-machining processes.
Electrical Engineering Team
The EE team looked into a variety of ways to implement the UI elements that we planned on incorporating, including a touchscreen, rotary dial, LED array, and mechanical switches. Ultimately, the team decided on pursuing an LCD touchscreen that unifies the user interface of the box while adding a level of modularity and updatability to the box that should bode well for future iterations. Also, the team is moving forward along the process of incorporating last quarter’s metering circuits into the charge controller PCB so that we can improve the space usage inside the box. Moreover, this should make the product more robust as there will be less loose wiring that can get undone in transport.