4-Wheel Smart Car Robot Chassis Kit, Double-Layer, 4x BO Motors

This 4-wheel smart car chassis kit steps up from a simple 2-wheel platform to a full four-wheel-drive layout, giving a sturdier, more stable base for carrying heavier payloads like a development board, a sensor array, or a small robotic arm. The double-layer transparent acrylic frame provides two mounting decks, one for drivetrain components and one for electronics, keeping wiring cleaner and components better organized than a single-deck chassis would allow, while still keeping everything visible for educational builds.

Four dual-shaft 200RPM BO gear motors drive the four wheels, each motor rated for 3V to 6V DC operation with a 1:48 gear ratio, a no-load speed of about 208RPM at 5V, and a rated torque of 0.8kg-cm at 5V, drawing roughly 170mA at 4.5V under load. Each motor weighs 28g and uses a 10mm, 6mm double-D shaft, a common standard that makes sourcing replacement wheels or motors straightforward if needed later. The wheels themselves are rated for a 2.5kg maximum load each, with a 65mm diameter, 27mm width, a black tire on a yellow rim, and a plastic body with a rubber grip surface for traction.

Four coded disks pair with the motors for encoder-style feedback, letting a controller track wheel rotation for more precise speed control or odometry calculations than open-loop driving alone would allow. The kit includes 8 acrylic fasteners, a 4xAAA battery holder, 6 connecting cables, 6 M3 copper standoffs, and a full set of M3 bolts and nuts in the two lengths needed for assembly, so the whole chassis goes together without needing to source additional hardware.

Educators, robotics clubs and hobbyists building a sturdier, heavier-duty robot platform than a basic 2-wheel kit allows, especially one that will carry a development board or sensor payload, will find this 4-wheel kit's extra stability and encoder-equipped motors a worthwhile step up.