Birdhouse Gadget Cache – Hidden Nail Puzzle with Decoy Hardware

This tricky birdhouse gadget cache is designed for one of our personal geocache hides, but it can easily be adapted for your own creative setups. It combines a visual red herring with a clever magnetic/nail-based locking mechanism, ideal for puzzle-loving finders.

🔐 How It Works

The front door is secretly held closed by a hidden nail.

To open the cache, the finder must identify the correct nut, unscrew it using a bolt, and extract the hidden nail.

The mechanism is disguised using multiple decoy nails and nuts.

The interior is spacious enough to hold a medium Hide-a-Cache kit, or other logbook/swag setups.

🛠 Assembly Notes & Materials Needed

You'll need some basic hardware to bring this to life:

• 5× M4 nuts (or any size you want to standardize on)
• 1× M4 bolt (to retrieve the correct nail)
• 4× 3" nails
• 8× 6×2mm magnets
• Superglue
• Optional: Drill or reamer to loosen the nail channel for smoother removal

Build Tips:

• Saw the heads off 3 of the nails and glue them in as decoys.
• The fourth nail should have the sharp end removed and be attached to the working nut.
• Mount the working nut behind the door’s perch to camouflage the puzzle element.

🌦 Outdoor Use

We recommend printing this in PETG or ASA for durability. This prototype was printed in PETG as a weather-resistant first attempt.

📦 Like This Cache?

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