Tamiya 70198 Wall-Hugging Mouse

Tamiya’s wall-hugging mouse is a fun and easy-to-build kit that’s great for new robot enthusiasts, and it can serve as a unique, hackable robot chassis for more advanced users. The mouse has no digital electronics; rather, a simple wire bumper along its side directs current to one of two motors to keep the mouse moving along the wall. The mouse features a hard plastic shell and runs on one alkaline AA battery.

Parts included with the Tamiya 70198 Wall-Hugging Mouse.

Tamiya 70198 Wall-Hugging Mouse assembled but not decorated.

The wall hugging mouse squiggles along a wall in a zig-zag manner. When the bump sensor makes contact with the wall, a switch directs power to the left motor, which moves the mouse to the right and away from the wall. When the bump sensor loses contact, the switch flips and directs power to the right motor, moving the mouse to the left and towards the wall again. This simple behavior allows the robot to follow almost any vertical surface on its left.

This is a very easy kit to put together. The electronics—motors, power switch, and bumper switch—are pre-assembled (no soldering is required) and snap into the plastic body with ease. Assembly only takes a few minutes, making this an excellent kit for beginners. The only tool required is a diagonal cutter, though Tamiya also recommends using a modeling knife to remove excess plastic.

Stickers for the ears, whiskers, and eyes are included, but the black paint that is needed to paint the nose as shown in the product picture is not. Tamiya recommends their TS-29 semi gloss black paint, though we got good results just using a black Sharpie.

Check out Tamiya’s wall-hugging ladybug to see a video of some wall-hugging bots in action. Note that the Tamiya ladybug is identical to the wall-hugging mouse except for cosmetic differences, and an example of assembly instructions can be found with the ladybug’s pictures. If you are looking for something that will be a bit more of an assembly challenge, check out Tamiya’s Robocraft Series of small mechanical animals that crawl, jump, or run with the use of gearboxes similar to the ones in the Tamiya gearbox kits.

Because this kit has two independent motors for differential drive, it can also serve as a base for your own project. There is ample space for adding your own electronics, and you can readily modify the plastic base.

Note: The wall-hugging mouse is a kit; assembly is required. One alkaline AA battery is required but not included (the mouse is not intended for use with NiMH batteries). Paint such as Tamiya’s TS-29 semi gloss black paint is required for painting the nose of the mouse but not included.