Boat.ReFlow
Retrofittable pedelec system for small craft: pedal power plus e-assist, with no hull modification.
THE TASK
Legs are stronger than arms. Can conventional paddle and rowing boats be retrofitted with a pedal drive, and, like an e-bike, electrically assisted on top? The goal: a system with minimal installation effort for a range of existing boats.
APPROACH
An electric power coupling instead of mechanical transmission. Crank and seat form one unit you simply place into the boat; a thruster with strap mounting allows reversible installation without cutting the hull. Two thrusters enable turning on the spot without a rudder.
CHALLENGES
- → Non-destructive mounting of the components on an existing boat
- → Transferring pedal energy from pedal to propeller without holes in the hull
- → Directional control without paddle or rudder
RESULT
A functional prototype, tested on the water: interface with OLED UI and 3-axis joystick, a small LiFePO4 battery integrated for electric assist. Parts of the system later became the technical basis of the subsequent solar-boat projects.
TECHNICAL EXECUTION
- → BLDC generator in the pedal module feeds two BLDC underwater thrusters
- → Propulsion and steering via differential power control
- → Strap mounting with cable routing, hull-adaptive and acoustically decoupled
- → Arduino-class µC with current sensing and OLED display, LiFePO4 buffer
- → Controller logic: balance mode (pedal-synced) and absolute mode (joystick)
WHAT STANDS OUT
The electric coupling enables non-destructive installation and easy e-assist. The dual-thruster system steers without a rudder at minimal draft.