Engino探索STEM力學套件-齒輪與蝸桿：9歲以上工程玩具（可組12款模型）

The rack-and-pinion models really make the mechanics click for my kid—he built three different setups in one afternoon and kept explaining the force-speed trade-off. It’s sturdy enough for learning, and the 12 builds give plenty of replay value.

My nephew is obsessed with the worm gear mechanism — he built a working crane in under an hour and kept explaining how the gear ratio lets it lift more weight. The 12 model options will keep him busy for weeks.

My 10-year-old spent a whole rainy Saturday building the rack-and-pinion model and actually explained gear ratios to me at dinner. The pieces snap together tight, though a couple of the smaller pins needed a bit of force. Twelve models means it won't sit in the closet after a week.