This is the third iteration of an idea I’ve been working on for a few years now and the first version that’s intended to be fully 3D printed. On the outside it appears to be a simple birdhouse however the entry hole is false and the birdhouse contains an inner compartment able to fit a small container. Specifically, it was sized to hold a 350ml Lock and Lock food storage container, perfect for a “small” sized Geocache.

The front of the birdhouse is a separate piece from the main body and is held in place by four pins. Giving the house a shake and a tap or using a magnet you’ll be able to remove the pins which will release the face plate and allow access to the internal compartment. The pins are four 3-inch “common nails” found at any hardware store for a few cents each. These are spaced intentionally to force the removal of all the pins to gain access to the interior compartment.

Also included in the body of the birdhouse are drainage holes on the bottom to allow the inner compartment to breath, and a hole through the top to mount the cache. This can be accomplished with a loop of rope knotted on the inside or a 3/16 inch eye bolt, also obtainable at most hardware stores.

One final optional feature are press-fit holes for 8x3mm neodymium magnets on the sides of the front plate. These are located near the holes for the pins to provide a little bit of magnetic pull when the pins are in place to help hold them in place.

The example was printed in Inland brand PETG to better resist temperature changes in the environment that may deform the holes for the pins. PLA should also work for the container but direct sunlight may heat materials enough to cause the aforementioned warping.