Dagu 4WD Thumper Mobile Platform is a smaller version of the Wild Thumper 6WD chassis. It is designed to excel at traversing rough terrain, making it a great platform for any robot that needs to perform tasks in a complex outdoor environment. It features four powerful DC motors with brass brushes and 34:1 or 75:1 steel gearboxes that drive large (120mm diameter) spiked tires, and a unique “super-twist” suspension system acts to keep each wheel in contact with the ground for maximum traction, even when driving over uneven or bumpy surfaces. The suspension can be adjusted to suit different loads and conditions. The chassis is made from a 2mm-thick corrosion-resistant anodized aluminum plate, all of the nuts, bolts, and screws are stainless steel, and the brass fittings and suspension springs are nickel-plated.
When Dagu 4WD Thumper Mobile Platform is powered at 7.2 V, the version of the chassis with 34:1 gearboxes can reach a top speed of approximately 7 km/h (4.5 mph), and each motor has a stall torque of roughly 5 kg-cm (70 oz-in). At the same voltage, the version of the chassis with 75:1 gearboxes can reach a top speed of approximately 3 km/h (2 mph), and each motor has a stall torque of roughly 11 kg-cm (150 oz-in).
Pololu Product Page:
https://www.pololu.com/product/1567