Tamiya 72008 4-Speed Worm Gearbox Kit

The primary feature of this gearbox is a worm gear, which locks the output shaft when the motor is not turning. Its high gear ratios of 84:1, 216:1, 555.4:1, and 1428.2:1 make this gearbox appropriate for small walking robots, lifting mechanisms, and other applications where high torque is desired.

33.95

Not currently available

Our Code: SKU-003203

Supplier Link: [Pololu MPN:2391]

Description

The Tamiya 72008 4-Speed Worm Gearbox kit includes one brushed DC motor and all the gears and parts to build any of the four possible gear ratio configurations: 84:1, 216:1, 555.4:1, 1428.2:1 . The four gear ratio options give you the flexibility to choose the best speed and torque for your project.

Tamiya 72008 4-Speed Worm Gearbox Kit

The kit includes step-by-step illustrated instructions in both Japanese and English. A scanned copy of the instructions is available on the Pictures tab. The kit can be built with just a screwdriver, but the instructions recommend having side cutters, pliers, and a modelling knife on hand.

Complementary products

This gearbox has a 4 mm diameter, round output shaft, which works with the wheels that are compatible with Tamiya 4 mm, round shafts and our 4 mm universal mounting hub. Our 3 mm universal mounting hub also fits on the smaller threaded end of the shaft, although it is not specifically intended to work with this type of shaft (the hub’s set screw could damage the thread on the shaft).

The low-voltage motor in this gearbox runs on 1.5-4.5 volts and draws up to a few amps when stalled, making it compatible with our DRV8833 motor driver carrier if appropriate precautions are taken to avoid stalling the motor.

The mounting holes on the gearbox are compatible with the Tamiya 70098 universal plate set and other Tamiya construction series products.

Features

One type 260 motor. For motor specs, see the Mabuchi motor RE-260 (#2295) data sheet (59k pdf).
Four different gear ratios:
- 84:1
- 216:1
- 555.4:1
- 1428.2:1
Worm gear (locks the output shaft when the motor is not turning)
4 mm round output shaft (length: 100 mm) compatible with Tamiya wheels for 4 mm, round shafts and our 4 mm universal mounting hub.
Assorted cranks

Note: The Tamiya 72008 4-Speed Worm Gearbox is a kit; assembly is required.

Specifications

General specifications

Typical operating voltage:	3 V
Gear ratio options:	84.0, 216.0, 555.4, 1428.2 :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.

Resources

File downloads

Mabuchi motor RE-260 datasheet (see model #2295) (59k pdf)

FAQs

Does this gearbox come with motors?: Yes, motors are included with the Tamiya gearbox kits.
How do I order the correct gear ratio for this gearbox?: The Tamiya gearbox kits come with all of the gears and parts necessary to build the gearbox in any of the possible gear ratio configurations.
What are the specifications for the motors included in this gearbox kit?: The Tamiya gearbox kits come with motors made by Mabuchi; please see the Mabuchi motor datasheet in the “Resources” section of this gearbox page for motor specs (be sure to look at the correct model number in the datasheet as indicated in the “Resources” link).
Is this gearbox suitable for my robot or project?: This gearbox is an eduational kit that you have to put together yourself. It is designed for use in small, indoor projects. The gearbox comes with plastic gears and small, low-voltage motors; if you are looking to build anything meant to work outdoors or in a rugged setting, you should be ready to replace the gearbox often or consider using a more robust, pre-assembled gearbox.
What kind of speed and torque will I get from this gearbox?: You can extrapolate a theoretical torque and RPM of the gearbox based on the gear ratio you build, the motor voltage, and the motor speed and torque. In general, this gearbox is a toy, so if you need very precise specifications, you might consider a more industrial gearbox.