72005 Tamiya 6-Speed Gearbox

The Tamiya 72005 6-speed gearbox is a versatile, high-efficiency gearbox that you can build in one of the following gear ratios: 11.6:1, 29.8:1, 76.5:1, 196.7:1, 505.9:1, and 1300.9:1. Whatever your application, chances are that one of the configurations will do the job. A clutch gear protects the gearbox in high-gear-ratio configurations so that the gearbox does not rip itself apart if the output shaft gets stuck.

The low-voltage motors in the 6-speed gearbox run on 1.5-4.5 volts and draw up to a few amps, making them perfect candidates for the Pololu low-voltage dual serial motor controller and the DRV8833 motor driver carrier (2130-POLOLU). Motor overheating can be caused by excessive stalling, even at very low voltages. We recommend that you use stall-detection sensors, or just watch your robot, to make sure that it doesn’t stall for more than a few seconds at a time.

This gearbox has a 4 mm diameter, round output shaft, which works with the wheels that are compatible with Tamiya 4 mm, round shafts.

For motor specs, see the Mabuchi motor RE-260 (#2295) data sheet (59k pdf). 

Note: The 6-speed gearbox is a kit; assembly is required. To use the kit in robotics projects, you need to connect the motors to your own robot controller.

General specifications

Typical operating voltage:	3 V
Gear ratio options:	11.6, 29.8, 76.5, 196.7,  505.9, 1300.9 :1
Free-run motor shaft speed @ 3V:	9400 rpm1
Free-run current @ 3V:	150 mA2
Stall current @ 3V:	2700 mA
Motor shaft stall torque @ 3V:	0.97 oz·in3

Notes:

1- A theoretical speed of the gearbox output shaft can be computed by dividing this speed by the gear ratio.

2- This is the no-load current of the motor when disconnected from the gears in the gearbox; the no-load current of the entire gearbox with the motor connected will be slightly higher and will vary depending on the gear ratio.

3- A theoretical torque of the gearbox output shaft can be computed by multiplying this torque by the gear ratio.