Wall-E Shelf

Inspiration

The film Wall-E (2008) features a shelf with motorised, vertically moving levels that allow the protagonist to sort a large collection of items. As Pixar fans, we decided to take the design even further - rather than manually controlled motors (as shown in the film), we opted for a fully-automated storage system.

What it does

The shelf features 3 trays, each containing 10 slots for 10 buckets. A bucket is registered by scanning its RFID and entering a name for it on our website. By inputting the bucket's name on the website, the user signals the motor to rotate the bucket's tray to the front and activate its LED. If the user removes the bucket and forgets where to place it back, scanning the RFID also rotates the tray to the front and activates the slot's LED.

How we built it

The trays are modeled in Onshape and laser-cut onto MDF, while the buckets are 3D-printed. LEDs are soldered on top of each slot. Two motors at the bottom are connected by steel wires to four 3D-printed wheels and controlled by the main ESP32. Each tray contains a minor ESP32 (3 total) for Hall Effects feedback, LED output, and communication with the main ESP32. The program is built in C++.

Challenges we ran into

• Connecting the trays to the wire rope without jamming the wheel mechanism
• Whether or not to tension the wire rope to prevent it from slipping
• Finding the proper interference fit for MDF panels
• Finding a way to power the moving trays without wires (which would entangle)
• Cramming under extremely short time. The parts we ordered only arrived 3 days before the due date, which made work schedule and team coordination very difficult.
• Running out of 3D printing filament halfway through printing

Accomplishments that we're proud of

• Rapid prototyping under extremely short time
• Implementing Hall Effect sensors for the first time
• Wiring and controlling unfamiliar motors without documentation to reference
• Managing to work as a team despite members having specialised areas of expertise that did not overlap (engineering, programming, and commerce). This made communication difficult across different fields but we managed to get everyone on the same page and allocate work effectively.

What we learned

• Improved soldering skills
• The importance of getting everyone on the same page in terms of technical details
• Brainstorming as a whole group and deciding on a concrete plan is a fundamental part of the project that should not be rushed
• Coordinating a time slot where every member is available despite conflicts with other commitments such as work and study

What's next for Wall-E Shelf

If given more time and budget, we aim to build a life-sized (~2m tall) prototype of the model, which would support wheelchair accessibility and function as a high-tech bookshelf / storage shelf / hydroponics wall.

Built With

• 3dprinting
• arduino
• c++
• esp32
• halleffect
• lasercutting
• rfid