FlipSpring Case (180x80x40)

FlipSpring Case (180x80x40) Automatically popping flip box with a spring button Three springs (0.4x5x25mm) are needed, with two for the box lids. The third should be cut in half for the button. You can also use the springs from my previous model (2 Ballpoint Pens) (0.4x4.2x25mm), but it’s best to use springs that are 25mm long and no more than 5mm in diameter. There are three types of Inner Shell available (2-cell, 4-cell, and 8-cell). When installing the Inner Shell, first insert the side n