This tracked chassis from Dagu Electronics makes a great base for building a small tank-like RC vehicle or autonomous robot.
The chassis includes a battery holder and two DC motors, with an independent drive train and a quadrature encoder for each tread, so all you need to add to make a complete robot is a robot controller and the sensors of your choosing. A unique mechanism allows you to configure the clearance of the chassis by adjusting the angle of the gearbox assemblies.
The Rover 5 tracked chassis, made by Dagu Electronics, is a durable robot platform with caterpillar treads that let it drive over many types of surfaces and uneven terrain. All you need to get the chassis moving is a robot controller or motor controller to drive the two built-in DC motors, which powered by the included 6-AA battery holder (AA batteries sold separately). A small Phillips screwdriver and an Allen wrench are included for working with the chassis.
The chassis features a rugged white plastic body with room to house the included battery holder and some additional electronics. The two powerful motors with 86.8:1 gearboxes are strong enough to lift the weight of the chassis and allow it to achieve speeds as high as 10 in/s (25 cm/s). The included encoders provide a resolution of 1000 counts per three revolutions of the wheel, or 333.33 CPR (counting both rising and falling edges of both encoder channels).
A unique feature of this chassis is the ability to adjust its height—and, therefore, the clearance under its body—by changing the angles at which the gearbox assemblies are mounted on the body. Interlocking teeth on the body and the gearboxes hold them in place and allow you to make adjustments in 5° increments by unscrewing a metal bracket inside the chassis, removing a gearbox, and reinserting it at a different angle. The elastic rubber tracks maintain sufficient tension with several different gearbox angles, allowing the chassis height to vary by nearly 1.5" (3.8 cm).
The outer dimensions of the chassis are approximately 9.5" long, 9" wide, and 3" tall in its default, flattened configuration (with the front and rear gearboxes mounted at an angle of 180° to each other).
- durable plastic body
- 6-AA battery holder included
- two brushed DC motors with 210 mA free run and 2.4 A stall current at 7.2 V
- maximum speed of 10 in/s (25 cm/s) at 7.2 V
- ability to scale inclines limited only by friction
- height and clearance can be varied by adjusting gearbox angles
- version with encoders features two 333 CPR quadrature encoders (one for each track)
- dimensions: 9.5" × 9" × 3" (24.5 × 22.5 × 7.5 cm) in default configuration
- weight: 1.6 lb (0.72 kg)
Using the Chassis
With only four motor leads and two battery leads, it is easy to interface the chassis with most dual motor controllers and robot controllers. Simply connect the battery holder leads to the controller’s power source and the motor leads to the controller’s motor driver outputs. Each set of motor leads is terminated with a female 3.96 mm pitch, 3-pin JST VH-style connector (the middle pin is not used), which male premium jumper wires plug into nicely.
The Rover 5 chassis with encoders has two additional bundles of wires, each containing the leads for the quadrature encoder’s 5 V power (red), ground (black), and signal (white and yellow) connections; the wires are individually terminated with female connectors that mate with 0.1" (2.54 mm) male headers. The Pololu AVR Library provides wheel encoder functions that make it easy to use these encoders for position feedback