Box with Centrifugal Locks

This took some work to get it work function properly, I tell ya... Total print time for me was 8 hours, 56 minutes. The hardest part of the print for your machine will be the bearings as they are print-in-place with no support. Simply (and carefully) break them loose with a small screwdriver after the print is done.

I will say it doesn't work exactly perfect. But that I expect is due to the small size of the ball bearings and the fact that they don't have a lot of mass. If they were SLS printed in metal, or replaced with small ceramic/steel bearings (2.79mm, or close. You've got about .41mm clearance on both sides in the bi-stable track), I imagine the function would be much more predictable.

EDIT 1 : Added alternate lids with different Triquetras on the top for a bit of design flare. Might need support to print these unless your bridging is boss-like.

EDIT 2 : Geocaching lids! Groundspeak official, as well as the G-compass. Most certainly will need supports.

EDIT 3