Challenges in Helicopter Toy Experiment

Mar 5, 2025

Lecture Notes on Helicopter Toy Experiment

Introduction

  • Helicopter toys are simple: spin between hands to store kinetic energy in the propeller.
  • Idea: Flywheel-powered helicopter to maximize height.
  • Initial design error: helicopter was prone to uncontrolled flight.

Mechanics of Helicopter Toys

  • Kinetic energy is stored in the propeller.
  • Air drag limits the rotational speed and height.
  • Supersonic speed creates a sonic boom but also immense drag.

Concept: Flywheel Augmentation

  • Slow propeller coupled with a fast-spinning flywheel.
  • Flywheel stores energy efficiently without the drag of a propeller.
  • Challenge: Mitigating the dangerous fall after energy depletion.

Proposed Solutions

  • Parachute Deployment

    • Pyrotechnically deployed parachute was considered.
    • Risk of entanglement with spinning blades.

  • Auto Rotation

    • Reverse blade angle to generate upward thrust on descent.
    • Concept borrowed from real helicopter emergency landing techniques.

Gyroscopic and Torque Challenges

  • Gyroscopic effects and procession would flip the helicopter.
  • Solution: Two counter-spinning flywheels to cancel procession.

Gear and Flywheel Design

  • Use of bevel gears to transmit motion at 90-degree angles.
  • CNC machining used to create light gears and flywheels.

Construction and Initial Tests

  • Metal construction; CNC and machining for custom parts.
  • Initial tests showed friction issues and motor limitations.

Troubleshooting and Adjustments

  • Flywheel drag identified as a major obstacle.
  • Solution: Enclosed flywheels to reduce air resistance.

Testing and Control Issues

  • Training gear used to stabilize during initial tests.
  • Control surfaces not strong enough to counteract torque.

Design Modifications

  • Larger wings on control surfaces to stabilize.

Final Test Outcome

  • Helicopter did not achieve stable flight due to torque overpowering control surfaces.
  • Acknowledgment of the need for a redesign to solve spinning issues.

Conclusion and Future Steps

  • Part two in the future to address the issues from this prototype.

Recommended Learning Resource

  • Brilliant: Platform for learning technical subjects through interactive lessons.

These notes summarize the experimental process and challenges faced in attempting to redesign a basic helicopter toy for maximum height and stability.