Frustrating Puzzle Box

This is a puzzle box I built to infuriate my friends. There is a secret to opening the box that is very hard to guess, and people will spend hours trying to open it. It is a perfect 1.25-inch cube with only a single seam around the middle.

There are two elements. The first is the actual locking mechanism, and the second is a pure distraction to keep them from finding the first mechanism.

The box is locked by a ball bearing held in place by a magnet preventing the lid from rotating. You can't discover or manipulate this magnet unless you apply an acceleration (a smack) to the correct face. If you hit it on the table, you break the magnet's hold on the bearing, and the bearing moves to a space allowing the box to rotate open.

There is also a set of three smaller bearings that roll around in three tracks. They do nothing, but you can hear them and move them around. This is a red herring. People will fixate on manipulating the bearings inside the cavities, so they will never try smacking the box. Hilarity ensues as they get increasingly frustrated that nothing works, and they hypothesize more complicated internals as reasons for their failure.

WARNING MAY RUIN FRIENDSHIPS

How to open the box:

1. Orient the box with the slightly heavier side upwards
2. Strike the box flat onto the table with moderate to high pressure
3. You should hear a click
4. At the same time, rotate the lid clockwise

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Update 2023:
My Amazon links from 2011 for buying the magnet and bearings no longer work.

My original magnet was a 3/8" disk by 1/16"thick, but a similar-sized magnet would work

I don't recall the original ball-bearing sizes, and I think they were 1/2" and 1/4". Evaluate the scale you will be printing and get bearings slightly smaller than the size of the internal tracks/cavities.

This was designed in Solidwork (see attached SLDPRT files). It was printed on my university's high-precision 3D printing machine. Using hobby machines may require tweaking the tolerance for a good fit.