This box is part of a collection of 6 3*3*3cm puzzle boxes that all have the same theme of lids being removed from boxes through unique and interesting means. They are ranked from 1-6 based on their difficulty even though putting these boxes together and seeing the inside mechanism can remove some of the mystery, they can still be interesting to solve and play with as well as give to your friends to try solve.Video

Printing settings:

supports: none       infill: 15%+ (The pin works better if it is heavier and is prone to shearing along print lines so you may want to use higher infill)

Extra materials:      

-Thin circular 1cm diameter magnet (like these) 

-A thin piece of sheet ferromagnetic metal (I used a snapped off piece of box cutter blade)

(You should test that the magnet and metal aren't attracted when 5mm apart)

Assembly:

1)Glue the magnet onto the tip of the pin and the metal onto the inside of the hole in the lid (look at the cross-section, blue=magnet, light pink=metal)

2)Place the pin into the hole in the case with the magnet facing up and make sure the pin does not sit above the face

3)Slide the lid onto the case and flip it upside down until you hear a click

Solution:

1)Holding the box up-right in one hand hit it down on the other palm until you can slide the lid off

(You may have to use quite a lot of force but you can adjust it by changing the strength of the magnet or size of the metal sheet)