A friend introduced me to geocaching yesterday. Without much success in finding any caches on my own, I thought I'd hide some instead.

Where better to hide your geocache log, but in a log!

Step 1: What You Need

You'll need some basic tools and consumables:

Small log/large branch - look for something an inch in diameter or preferaby bigger. Should be reasonably dry, but not brittle.
Saw
Drill and drill bit (12 - 20mm is good)
Hammer
Wood glue (I used cyanoacrylate and UHU Hart, but any will do)
PCB pins (not pictured, they're tiny anyhow)
Long nosed pliers or similar to hold PCB pins while hammering
Sharpies (optional)

Step 2: Cut in Two

Choose a nice log and cut it cleanly in two. For a better result try to keep the cut sharp, square and avoid knocking the bark off (difficult!).

Step 3: Drill Out Centre

You now have two pieces of log, with a clean edge on one end. You need to drill this out. It's your choice how large a hole you make, I used 16mm and 12mm drills leaving a good few mm of wall. You need enough wall to put the locating pins in later so don't go too thin.

If you keep the drill straight you can make a rather deep chamber. Drill as far as you dare without going through the sides!

Step 4: Insert Pins

Place three PCB pins in one log. You want to place them roughly equidistant around the log, but don't worry too much about accuracy as the thicker areas will take them better. You may well need to use long nosed pliers to hold the pins while hitting them with a hammer rather than your fingers.

Once in, I found it useful to glue them. This keeps the pins in one piece of wood and stops them getting lost.

I also found it worthwhile to colour code the pins so you can more easily put the stick back together later. Do this before glueing.

Step 5: Alignment

This is the critical bit. You need to line the two piece of wood up and push the pins into the second piece. You only really get one go, although if you're miles off you might get another. Take a good look at the wood (and ideally test fit prior to fitting the pins) and work out exactly where it should join.

Light force is all that's needed to push the wood together, and the same should take it apart. But the fastening should be pretty rigid once done.

If you find the pins holes a bit loose, a dab of glue might help. You'll have to repeatedly fasten and undo the cache while the glue sets to keep the holes open.

(If you've more time on your hands, it might be worth repeating steps 4 and 5 with one pin at a time. YMMV.)