Wind-Powered Self-Steering
System
Research Presentation for Barbary 32
Sailboat Design
1. Introduction
• This project outlines a mechanical selfsteering system for the Barbary 32 sailboat.
• The system uses wind direction as input and a
servo paddle for torque correction.
2. System Overview
• Control Path:
• Wind ➜ Wind Vane ➜ Linkage ➜ Rudder
Sensor ➜ Servo Paddle ➜ Torque ➜ Course
Correction
• Key Concepts:
• - Mechanical feedback
• - Servo mounted after the rudder
• - Wind-driven, electricity-free
3. Mathematical Basis
• Wind Vane Torque:
• T_v = F_w * A_v * sin(θ_e) * d
• Servo Paddle Force:
• F_s = 0.5 * ρ * v² * A_s * C_L
• Rudder Correction:
• T_r = F_r * l
• Students must:
• - Understand each variable
4. Design Parameters
• Students must determine:
• - Optimal vane area (0.02–0.05 m²)
• - Paddle surface (0.04–0.08 m²)
• - Amplification ratio (500–2000x)
• - Boat operating speed range
5. Mechanical Layout
• Updated layout with servo paddle mounted
aft of the rudder:
• Wind ➜ Vane ➜ Link ➜ Rudder Sensor ➜
Servo Shaft ➜ Paddle ➜ Water Deflection ➜
Steering
• Students should sketch, model, or simulate
this configuration.
6. Simulation Parameters
• Students must build a spreadsheet to
simulate:
• - Wind speed, boat speed
• - Torque output
• - Force vs. angle plots
• Include formula cells to validate calculations.
7. Design Challenges
• - Rope routing to rudder quadrant
• - Material selection for low weight, high
stiffness
• - Dampening strategies to avoid oscillation
• - Mounting constraints on the Barbary 32
8. Next Steps
• - Finalize 3D model and linkage
• - Prototype wind vane and servo paddle
• - On-water testing at 3–5 knots
• - Iterate design based on performance