Project · UBC Design League Designathon
The 4Ward Thinker — a modular robotic meal-serving system
The 4Ward Thinker was designed during a 48-hour engineering sprint: an affordable, mass-manufacturable meal-serving robot capable of carrying a load up to 60kg (backed by stress analysis testing) while remaining modular, maintainable, and feasible for real-world deployment in cafeterias, senior homes, and hospitals.
Our goal was simple: build a robot that’s strong enough to handle real loads, safe enough to move around people, and cheap enough that scaling to dozens of units is realistic — all while completing the entire concept, CAD, stress analysis, and electronics layout in under two days.
Primary CAD assembly — tray structure, outer shell, and base frame
Designed around detachable side panels, independent enclosures, and standardized mounting points for sensors and batteries.
Minimum tray footprint of 30cm×40cm, with parametric sizing for different dish sets and kitchen standards.
Stress-tested to withstand up to 15kg per tray × 4 trays using Fusion360 simulation tools.
Sliding lid rails on each tray edge keep dishes from slipping during motion or sudden stops.
Six ultrasonic sensors validate safe forward motion, turning radius, and obstacle thresholds.
Dedicated, ventilated housing for motor drivers, battery pack, and cable routing.
Mechanical Design Notes
The assembly weighs 32.67kg, balancing stability with portability. PLA was chosen as a low-carbon-footprint material that still offered the stiffness required for our short development timeline.
Tray geometry, lid thickness, bending stress, and expected fatigue regions were simulated in Fusion360. This ensured that the tray arms wouldn’t flex under full load or during acceleration.
- Finite-element simulation for tray bending and torsion.
- Motor enclosure with isolated vibration paths.
- Cable routing channels for fast assembly and maintenance.
- Battery compartment with passive cooling gaps.
- Trays designed for easy-to-replace lid mechanisms.
Exploded view — structural rails, battery compartment, and tray arm assemblies
Rapid engineering
Going from concept → CAD → simulation → electronics in under 48 hours was the real challenge — not just the robot itself.
Design for manufacturing
Every part was chosen with real costs and tooling in mind, not just appearance. Scaling to dozens of units had to be realistic.
Cross-disciplinary workflow
I handled CAD modeling, stress analysis, and electronics layout — ensuring mechanics, sensors, and circuits fit a unified design.