Design Concept
This 3D-printed model is a creative toy fish whose internal mechanism allows the mouth to open when the tail is pressed. It seamlessly combines mechanical functionality with playful design, making it a beloved toy for children.

Applications
This toy is primarily intended for children’s entertainment, while also introducing them to basic mechanical principles through interactive play.

Printing Recommendations
We recommend using PLA or PETG filaments, as these materials offer high strength and safety—ideal for children. During printing, ensure strong interlayer adhesion and proper machine calibration to maintain the smooth operation of the tail‑based mechanical mechanism.

Assembly Instructions
After printing all components, attach the fish head to the body. Thread an elastic band through the two central holes to provide the spring‑back force. The connection between the mouth and the body is secured using filament. If any parts become loose, you can gently heat and flatten the filament ends with a lighter, or apply a small drop of glue to secure them. To use, simply press the tail to activate the reciprocating opening motion of the mouth.