THE DRIVETRAIN.
A traditional geometry with four-wheel drive, independent suspension, and 80 mm all-terrain tyres. The same Ackermann kinematics as the F1TENTH reference car, so the same control laws carry over.
THE BRUSHED MOTOR.
A purpose-spec brushed motor with integrated encoder. Brushless motors give better top-end and efficiency, but brushed motors stall cleanly when you bump a wall, which is the failure mode we wanted for a classroom car.
No-load: ~11,000 RPM
Drive: All four wheels, fixed reduction
Closed loop: MCU (microcontroller unit) velocity controller (see Compute)
THE STEERING SERVO.
The steering servo is heavily over-specified for a 380 mm car. That margin is intentional, you can hit a wall at modest speed and the servo will not strip its gears. It's also waterproof, which mostly matters for spilled drinks in classroom labs.
STEERING KINEMATICS.
Steering follows simple bicycle geometry: steering angle δ and wheelbase L = 280 mm give path curvature κ = tan(δ) / L. That kinematic relation is the low-speed baseline, and the Playground's 2D hub runs on it directly. The 3D challenge sim now goes further and models the car as a , tuned to the real RC car's mildly understeering feel. Pure-pursuit or controllers written for F1TENTH still carry over directly; the dynamic model just means tyre slip and weight transfer show up at the limit, the way they do on the real car.