Engino Discovering STEM 역학 세트: 캠과 크랭크 장난감, 9세 이상 어린이용 (8개 모델 조립)

My son finally understood how a crankshaft turns circular motion into the up-and-down stroke of an engine piston—the snail cam model made that click instantly. We’ve already rebuilt three of the 8 models, and the pieces stay snug through all his testing.

The crankshaft model actually turns the way a real engine does, which my son thought was the coolest part. Instructions were clear enough that he built all 8 models without needing my help.

My 10-year-old built the crane model first and spent a solid hour just testing how the cam made the arm lift. The instruction booklet breaks each of the 8 builds into clear steps, so he barely needed my help.