Getting the top open is a sequential puzzle.
First, the drawer is moved to a specific marker dot on the drawer sides. This frees the medallion to be rotated until it hits a stop. The drawer is then moved to a different dot and the medallion can then rotate more and open the latch.
The pictures below show how it works.
The sides of the drawer are marked with inlaid dots. Near one of the dots on each side is a magnet. This was done by drilling the sides and gluing in a magnet, then veneering over them.
In a recess behind the front of the box is the lock mechanism. At the end of each arm is a magnet faced to oppose the magnets in the drawer. The spring on each arm keeps it in the locked position.
When the drawer is open so that the magnet on the left side is in position, the left pawl will rotate, allowing the disk to turn CW (from this view) until the boss on the right hits the right pawl.
If the magnet on the right is positioned first it will activate the right pawl, but the left pawl keeps the disk from turning.
Once turned, the boss on the bottom of the disk keeps the left pawl from re-engaging.
When the drawer is slid to the second marker, a magnet on the right side rotates the right arm rotating the right pawl allowing the top boss to release the latch.
The medallion can be reset at any time - the latch is spring loaded and will allow the top to close.
The brass parts were all cut at Send-Cut-Send. Happy to share the CAD files for them and the pocket with anyone who wants.
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