From Retired to Ready: Alex Machuca Rebuilds Drones for the Future of Swarm Flight

What began as a set of aging, do-it-yourself quadcopter kits is now becoming a platform for advanced autonomous research, thanks to Embry-Riddle Aeronautical University Uncrewed Aircraft Systems (UAS) student Alex Machuca.

The project, known as Flame Wheels, focuses on restoring legacy quadcopters by updating components, programming modern flight-control systems and performing the calibrations needed for safe, repeatable operation. Under the guidance of faculty mentor Avinash Muthu Krishnan, assistant professor of Aeronautical Science, Machuca is transforming retired aircraft into reliable research tools that will soon support early experiments in swarming algorithms.

“Outside the UAS world, I describe it as taking retired drones and rebuilding them into reliable aircraft that can be validated through structured ground checks and test flights,” Machuca said. “Reliability depends on how well hardware, wiring, firmware settings and sensors operate together.”

Why rebuild instead of start new?

Rather than using turnkey platforms, Machuca chose to restore older airframes to create a more realistic engineering environment. Every system must be verified for compatibility, from power and propulsion to avionics and sensors.

“Small integration errors show up quickly in sensor performance, arming checks and flight stability,” Machuca explained. “That process builds discipline because success depends on integration and calibration, not just new parts.”

The approach also recovers value from existing departmental assets and creates test platforms that can be used for repeatable experiments once stability is confirmed.

Much of the restoration effort centers on the subsystems that directly affect stability, especially the power and propulsion chain and the avionics and sensor stack.

Intermittent electrical issues, wiring paths, vibration and sensor placement all play a role in whether the aircraft behaves predictably. To manage that risk, Machuca follows a structured workflow that treats integration as a staged retrofit rather than a quick rebuild.

“Flight readiness means passing a clear checklist across integration, programming and calibration, not just that it turns on,” he said.

Each quadcopter must pass mechanical, electrical and software checks, including pre-arm safety logic that prevents flight if sensor data or configurations are not acceptable.

Testing, data and iteration

Flame Wheels test flights will be introduced gradually, beginning with bench checks and restrained run-ups before progressing to controlled hovers and basic maneuvers.

“We do not discover problems at altitude,” Machuca said. “Each step has pass and fail criteria and clear abort conditions.”

Data collection will focus on vibration levels, attitude stability, estimator behavior, power draw and fault indicators, metrics that reveal whether the aircraft and sensors are behaving consistently.

Once the restored aircraft demonstrate stable and repeatable performance, Machuca plans to introduce simple multi-vehicle coordination behaviors.

“Swarming algorithms are coordination methods that allow multiple aircraft to operate as a cooperating group rather than as independent vehicles,” he said.

Initial experiments will include leader-follower flight, spacing rules and basic task distribution, laying the groundwork for cooperative autonomy research.

Learning beyond the classroom

Through Flame Wheels, Machuca has gained hands-on experience that extends well beyond traditional lab exercises, including power management, signal routing, sensor mounting, change documentation and data-driven troubleshooting.

“Treat integration, programming and calibration as one system,” he advised students interested in similar work. “Change one thing, test it, log results and document what you learned before moving on.”

Faculty guidance has been essential in keeping the project focused on safety, verification and long-term usability.

“Alex has approached this project with the mindset of a systems engineer,” said Avinash Muthu Krishnan, assistant professor of Aeronautical Science. “He understands that autonomy starts with platform reliability, and he has shown the discipline needed to build aircraft that are not only functional, but research ready.”

For Machuca, that mentorship has shaped how he evaluates progress.

“Guidance on integration priorities, calibration standards and test planning reduced risk and kept the focus on what improves safe operation,” he said.

With test flights planned soon and early swarm behaviors on the horizon, Flame Wheels is proving that innovation does not always begin with something new. Sometimes, it starts by rebuilding what already exists and making it better.