Impossible?? to open gift box

This gift box looks like it's impossible to open it. But you can, if you know the trick. It has an inside space of 70x70x15 mm to hold banknotes, concert tickets, vouchers, jewellery or a wedding ring. A hidden magnet and a steel ball lock the box. If you hit the box with the printed question mark facing down hard on a table, the ball will detach from the magnet, falls into the hole and you can slide the upper part of the box diagonally to open it.

Print instructions

Category: Containers Print Settings

Printer Brand: Prusa

Printer: i3 MK3 MMU 2

Rafts: No

Supports: No

Resolution: 0.2mm, Dovetail 0.1mm

Infill: 15%

Filament: 3djake PETG

Source of Hardware

Neodym Magnet W-05-N: www.supermagnete.ch (They ship to all EU countries)
Steel ball: Ball bearing for a Modell truck: www.conrad.com (They ship worldwide)

Tips

Before assembling the magnet, make sure the box can be closed and opened with low friction. If the friction is too high, sand the top of the dovetail shapes. Make sure, the ball can fall without any friction into the hole. Use a 8mm drill to clean up the hole in case the ball can't fall into the hole freely. In case your magnet is too strong, print a 8mm spacer over the magnet to have a certain distance between the magnet and the ball.

Happy printing