Lesson 4: Propulsion and Motor Placement
Duration of Days: 4.5
Lesson Objective
Students will mount an electric motor and determine the optimal depth for the propeller to maximize thrust and minimize drag.
1. What happens if the propeller is submerged too deep?
2. How does the angle of the motor affect the direction and "lift" of the boat?
Thrust, Cavitation, Propeller Pitch, Submersion Depth, Torque.
ENG.05.04: Apply principles of mechanical power and simple machines.
Students install DC motors and batteries. They conduct "Static Thrust" tests where the boat is tethered to a scale while the motor runs to measure pull-force at different depths.
Purpose: To find the "Goldilocks zone" of propeller placement.
DOK Level: Level 3 (Strategic Thinking).
Provide pre-made adjustable motor mounts (slotted brackets) to make the trial-and-error process less frustrating.
A "Depth-to-Thrust" graph showing the most efficient motor position.
DC motors, plastic propellers, battery packs, waterproof wiring, motor mounts