Tamiya 71125 Mechanical Fish Build Kit  [71125]

Tamiya 71125 Mechanical Fish: Compact Robocraft Build

The Tamiya 71125 Mechanical Fish brings a compact, practical STEM project to the Robocraft line, combining simple mechanics with a seaworthy aesthetic. It lets builders test how linkages translate rotary motion into a swimming action.

Drive Mechanism and Buoyancy

The tail is driven by a crank arm assembly to imitate natural swimming. The top half of the hull acts as a float so the dorsal fin stays visible while the remainder submerges, and the tail and lower fins are adjustable to change motion patterns.

Assembly and Power Basics

No glue is needed for construction, keeping the kit approachable for beginners. The motor runs on 1 x AAA battery (not included), offering a straightforward example of small-scale electrical power and motor behaviour.