30lb Combat Robot

This 30lb combat robot pushes the boundaries of kinetic energy weapons and defensive armor in the heavyweight division. The design philosophy prioritizes weapon power and drive performance while maintaining structural resilience against opponent attacks.

The bot competed in multiple tournaments, facing opponents with various weapon systems including horizontal spinners, vertical discs, and crushing mechanisms. Design validation occurred through both virtual simulation and real combat testing, with iterative improvements based on fight performance.

The chassis uses a dual-layer structure: 1/4" AR500 steel bottom plate for ground scraping protection and 3/16" titanium top armor for impact resistance. The frame geometry creates a wedge profile for defensive positioning and weapon protection.

The weapon system consists of a 4lb hardened steel spinning bar powered by a 5065 brushless outrunner motor. The weapon achieves tip speeds exceeding 200mph, storing significant kinetic energy. The weapon mount uses pillow block bearings with custom shock absorption to survive weapon impacts.

The drive train employs four independent 22mm gearmotors (2 per side) with custom 3D-printed TPU wheels for traction. The four-wheel drive configuration provides excellent pushing power and maneuverability. Drive motors are mounted on isolated shock-absorbing plates to protect against impact damage.

All structural components underwent FEA stress analysis with particular attention to weapon mount stress concentration points. Critical fasteners use vibration-resistant threadlocker and safety wire. The modular design allows rapid field repairs and component replacement between matches.

The power system centers around a 6S 5000mAh LiPo battery providing 22.2V nominal with 100C discharge capability, supporting burst currents exceeding 500A. The battery is housed in a protective kevlar sleeve and secured with aircraft-grade velcro and retention straps.

The weapon motor uses a dedicated 120A ESC programmed for maximum acceleration and regenerative braking disabled (for combat safety). Drive motors interface with dual 60A ESCs supporting tank drive mixing. All ESCs feature BEC disabled with a dedicated switching regulator providing 5V for receiver and servo systems.

The radio system uses a 2.4GHz Spektrum receiver with failsafe programming to disable all motors if signal is lost. A removable link serves as the primary power disconnect for safety protocols. Emergency stop (passive weapon brake) can be triggered via dedicated switch.

All wiring uses 12AWG silicone wire for power distribution with Anderson Powerpole connectors for modularity. The electronics are protected by shock-mount foam in an internal compartment with conformal coating on PCBs. The entire electrical system fits within a 500g weight budget.

The robot competed in regional combat robotics tournaments, achieving a 6-3 win-loss record in its debut season. The weapon system proved highly effective, achieving several knockout victories through kinetic impact damage. Drive performance allowed strong positional control and pushing power against opponents.

The armor successfully withstood hits from comparable-weight horizontal spinners with minimal permanent deformation. One titanium panel required replacement after a particularly heavy impact, validating the modular repair approach. The four-wheel drive system proved reliable with zero drive motor failures across 9 matches (27 minutes of combat).

The weapon motor ESC experienced overheating during one extended match, leading to redesigned cooling air flow for improved thermal management. Battery life sustained 3-minute matches with power to spare—the weapon maintained full speed throughout all fights.

Key lessons included the importance of redundant weapon mount fasteners and the effectiveness of titanium for impact resistance. The bot has since received upgrades including enhanced weapon teeth geometry and improved ground clearance based on competition feedback.