Testimonials Testimonials

Newsletter Newsletter

Save 7%
Tamiya 70189 4-Speed Mini Gearbox

Tamiya 70189 4-Speed Mini Gearbox

List price: £11.95  
(£11.15 exc. tax) You save: £0.80 (7%)
Price in points: 2230 points
80.00 g.
1 item(s)
End of line, less than 2 remaining
Add to wish list


The mini-motor gearbox kit from Tamiya makes it easy to get a small robot or plastic model moving. The kit includes one motor and all the gears and parts to build any of the four possible gear ratio configurations: 71.4:1, 149.9:1, 314.9:1, or 661.2:1. The four gear ratio options give you the flexibility to choose the best speed and torque for your project.

The gear train of the low-speed gearbox includes a self-locking worm gear, which means the gear train can not be back-driven (the motor can spin the output axle in both directions, but you cannot turn the output axle with your hand). Not being able to back-drive the gear train is useful when powering vehicles that stop on steep inclines, or when powering mechanisms that lift heavy objects off the ground (like gates or drawbridges).

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, tweezers, and a modeling knife on hand. The gearbox kit’s motor has a 030 form factor that is smaller than the Tamiya gearboxes that use the Mabuchi FA-130 motor.


  • 030-form-factor motor
    • Speed @ 3 V: 8400 RPM
    • Free-run current @ 3 V: 60 mA
    • Stall current @ 3 V: 600 mA
    • Stall torque @ 3 V: see picture to the right for torque table
  • 4 different gear ratios, which can be adjusted by changing the final gear position
    • 71.4:1
    • 149.9:1
    • 314.9:1
    • 661.2:1
  • Self-locking worm gear prevents gear-train from being back-driven
  • 3mm hexagonal output shaft compatible with the LEGO wheel adapter for 3mm hexagonal shaft and many of Tamiya’s wheels - see the 'Which Wheel' tab for type HEX for a tight fit.
  • Two mounting orientations
  • Mounting holes designed to work with the Tamiya 70098 universal plate set and other Tamiya construction series products.
  • Transparent gear housing shows the internal mechanisms
  • Compact size of approximately 20 x 24 x 30 mm (0.8" x 1" x 1.2")

General specifications

Typical operating voltage: 3 V
Gear ratio options: 71.4:1, 149.9:1, 314.9:1, and 661.2:1
Free-run speed @ 3V: 8400 rpm1
Free-run current @ 3V: 60 mA2
Stall current @ 3V: 600 mA
Color: clear


This is the speed of the motor when disconnected from the gears in the gearbox.
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.

Manufacturer's Details

Manufacturer's SKU :

No posts found

Write a review

Will the Tamiya 70189 4-speed mini gearbox motor work at 6v furlong periods

Asked by John | 26/06/2014, 16:22 | 1 answer(s)

Customers also bought....

£4.78 (£3.98 exc. tax)
New lower price - was £5.03 A multi-ratio gearbox supplied in kit form which allows eight different transmissions from 5:1 to 1125:1. *... read more
In stock
Price in points: 796 points