# Tamiya 70189 Mini Motor Low-Speed Gearbox (4-Speed) Kit **Type:** Product page · **SKU:** POLOLU-1684 · **Brand:** [Pololu](https://core-electronics.com.au/brands/pololu-australia) **Page:** https://core-electronics.com.au/tamiya-70189-mini-motor-low-speed-gearbox-4-speed-kit.html ([markdown](https://core-electronics.com.au/tamiya-70189-mini-motor-low-speed-gearbox-4-speed-kit.html.md)) ## Retired product This product is retired and no longer available for purchase. Search the catalogue for an alternative. ## Description The mini-motor gearbox kit from Tamiya makes it easy to get a small robot or plastic model moving. The kit includes one brushed DC 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). | ![](https://a.pololu-files.com/picture/0J2182.600.jpg?49235c740da17ac4a5fd7445ef25b04e) | |---| | Parts included with the Tamiya 70189 mini motor low-speed gearbox (4-speed) kit with quarter for size reference. | 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](https://core-electronics.com.au/st-1-mini-diagonal-cutter.html), [tweezers](https://core-electronics.com.au/tweezers-curved-esd-safe-10183.html), and a modeling knife on hand. The gearbox kit’s motor has a 030 form factor that is smaller than the [Tamiya gearboxes](https://core-electronics.com.au/category/34/tamiya-motors-and-gearboxes) that use the [Mabuchi FA-130 motor](https://core-electronics.com.au/tamiya-980112m-mabuchi-fa-130-motor.html). | \| [![](https://a.pololu-files.com/picture/0J2172.300.jpg?cf455658c06df7446c4bc7b91a4552de)](https://a.pololu-files.com/picture/0J2172.1200.jpg?cf455658c06df7446c4bc7b91a4552de) \| \|---\| \| Box front for Tamiya mini motor low-speed gearbox (4-speed) kit. \| | \| [![](https://a.pololu-files.com/picture/0J2166.300.jpg?8992f5c2fbe4242fd0a4718ad841445b)](https://a.pololu-files.com/picture/0J2166.1200.jpg?8992f5c2fbe4242fd0a4718ad841445b) \| \|---\|---\| \| Instructions for Tamiya mini motor low-speed gearbox (4-speed) kit page 3. \| | |---| | [![](https://a.pololu-files.com/picture/0J2173.250.jpg?cebcecaea4c03cae39276fb7f381b5d2)](https://a.pololu-files.com/picture/0J2173.1200.jpg?cebcecaea4c03cae39276fb7f381b5d2) | |---| | Box back for Tamiya mini motor low-speed gearbox (4-speed) kit shows the possible gear ratios in orange. | **Features** - 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 - 3 mm hexagonal output shaft compatible with Pololu's [adapter for LEGO wheels](https://core-electronics.com.au/3mm-hexagonal-shaft-adapter.html) and many of [Tamiya’s wheels](https://core-electronics.com.au/category/35/tamiya-wheels). - Two mounting orientations - Mounting holes designed to work with the [Tamiya 70098 universal plate set](https://core-electronics.com.au/tamiya-70098-universal-plate-set.html) and other [Tamiya construction series products](https://core-electronics.com.au/category/61/tamiya-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") **Note:** The Tamiya 70189 mini motor low-speed gearbox (4-speed) is a *kit*; assembly is required. **People often buy this product together with:** | [![Tamiya 70103 Universal Gearbox Kit](https://a.pololu-files.com/picture/0J278.100.jpg?3a8291376ead64cd3aa5660f4e34213d)](https://core-electronics.com.au/tamiya-70103-universal-gearbox-kit.html) | [Tamiya 70103 Universal Gearbox Kit](https://core-electronics.com.au/tamiya-70103-universal-gearbox-kit.html) | |---|---| | [![Tamiya 70105 3mm Diameter Shaft Set](https://a.pololu-files.com/picture/0J2705.100.jpg?f703aa572bcc793390ca6b06fce9560b)](https://core-electronics.com.au/tamiya-70105-3mm-diameter-shaft-set.html) | [Tamiya 70105 3mm Diameter Shaft Set](https://core-electronics.com.au/tamiya-70105-3mm-diameter-shaft-set.html) | |---|---| | [![Tamiya 70188 Mini Motor Gearbox (8-Speed) Kit](https://a.pololu-files.com/picture/0J2210.100.jpg?d9445c5038a1b5f0e9c55e2fe2d08cda)](https://core-electronics.com.au/tamiya-70188-mini-motor-gearbox-8-speed-kit.html) | [Tamiya 70188 Mini Motor Gearbox (8-Speed) Kit](https://core-electronics.com.au/tamiya-70188-mini-motor-gearbox-8-speed-kit.html) | |---|---| **General specifications** | Typical operating voltage: | 3 V | |---|---| | Gear ratio options: | 71.4, 149.9, 314.9, 661.2 :1 | | No-load motor shaft speed @ 3V: | 8400 rpm[1](https://core-electronics.com.au/#note1) | | No-load current @ 3V: | 60 mA[2](https://core-electronics.com.au/#note2) | | Stall current @ 3V: | 600 mA | | Color: | clear | **Notes:** 1A theoretical speed of the gearbox output shaft can be computed by dividing this speed by the gear ratio.2This 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. ## Images - [Product image 1](https://core-electronics.com.au/media/catalog/product/t/a/tamiya_70189_mini_motor_low_speed_gearbox__4_speed__kit__pololu_1684__00.jpg)