This is my second version of a dead drop spike. It is based off of several designs I saw in a book on spy gadgets. They would have been used for passing stolen documents and film between an agent and their handler, storing money and documents as well as other tasks. More practically it would work quite well as a geocache.
The advantages of this design are:
1) The lid locks in place. The previous version is only a friction fit which means that you have to have a pair of pliers if you want to remove the body.
2) There is an o-ring to seal the lid.
3) The lid and spindle are detached allowing it to be removed if you want to place a USB drive or some other object inside.
I have also lengthened the side wall by 1/2" and shortened the shank of the point by 1/8".
Cost for materials: ~$20 Canadian. (I had some of the materials and scrounged the rest. It might cost more if you have to buy a longer section of pipe.)
• Pipe cutter (optional)
• Lathe with cross slide
• 1/8" dremel bit
• 1/16" dremel bit
• 17/64" drill bit
• 1/8" drill bit
• 1/4" bit (I used 3/16")
• 1/4" milling bit (optional)
• Small file
• 1/8" diameter rod
• Glue applicator
• Mixing dish if using 2 part epoxy
• 1" long section of 3/4" aluminum rod.
• 1 1/2" long section of 3/4" aluminum or plastic rod.
• 3/4" external diameter, 4" long section of aluminum pipe
• Two 1/4" long sections of 1/8" diameter stainless steel, steel or aluminum rod
• O-ring that is as close to 3/8" internal and 5/8" external diameter as you can find. You will likely have to get a mixed bag with a couple of spares
• 1/2" long section of 1/4" stainless steel, steel or aluminum rod
• 9" long section of 1/16" diameter wire
• glue intended for use with metal
• About a foot of strong string.
Step 1: The Side Wall
Cut the 3/4 inch diameter pipe to length (4 inches). Round off any burr that is formed. At one end of the pipe cut two pairs of 1/4 inch long guide lines on opposite sides with the hacksaw and then open them up with the 1/8 inch dremel bit.
You can either mark and cut the grooves for the locking lugs now or wait until the top has been made, but not assembled, and use it as a guide for the 1/8 inch dremel bit.
This is the side wall.