I originally made this to use as a Geocache but you could also use it to hide anything small enough to fit inside I suppose. Hung low on a fence or on a bike rack, it looks normal and most people ignore it.
Step 1: Obtain Warded Lock(s)
Depending on the size of lock you want to make, you may want to pick up a couple of locks. I got a package of 3 at a local hardware store for 5 bucks. To make this easier get WARDED LOCKS. They are simple and cheap. They are one of the most insecure type locks so this makes them cheap. It will also make it easier to tear apart and reassemble and the hasp might even still "lock" and work as mine ended up doing. Also be sure to get the type of padlock that is put together in layers and not solid.
Step 2: Dissassemble the Lock
I cut off the small heads of the pins with a dremel cut off wheel and then pressed out the pins holding the lock together one at a time. Be sure to hold the lock together and observe how it is put together so you can put it back together later. Some locks have 6 pins holding them together, mine was real cheap and had only 4, one in each corner.
Step 3: Continue to Disassemble
Remove the pins one at a time and continue to disassemble the lock. Note how and where the hasp latch is and how it works. Mine had 2 small springs, one for the hasp latch and another spring for the hasp to pop up when unlocked.
Step 4: Remove Wards
Remove the ward sections. These are the sections that match up to the cut outs on the key, they prevent just any old key from opening the lock.
Step 5: Reassemble Without Wards...
Now reassemble lock. Be sure to leave out the ward sections and any other section that will block your container you plan to fit inside. I ended up using 3 locks and making one out of all 3. This allowed me to build up the lock in height while at the same time keeping the lock looking like a lock. I used nails in place of the corner pins and my container to test fit everything together to make sure it was the right height and everything worked like I wanted.
Step 6: Final Assembly
I found some 3 inch, 40/40 threaded rods at my local hardware store. They fit in the corner pin holes perfectly on my locks. I used two nuts on each one, one on top and one on bottom and screwed everything together using locktite. Then I used the dremel tool and rounded the nuts and cut off the extra length of the rods flush with the nuts. You may find a different size bolt or rod that may fit better in your lock depending on the size of the holes the pins where in.
Step 7: Finish
If you reassembled the latching mechanism right, you should be able to reach inside with a small screwdriver and press it back and it will unlock like a normal lock. This will allow you to "lock" it onto a gate or fence or what ever so it blends into the enviroment