After seeing merijnvw's instructalbe I decided to make a cryptex of my own. The first version, was much bigger, because I made it without fully understanding how he made his. Then I proceeded to make another on (the one in all of the pictures) using an idea that would allow there to be no spacers. I then realized after making it that is was the exact same way he made his. I guess I should have just read more thoroughly in the first place. The main idea is that there is dials that spin, and when they are all lined up, the key slide through the notches in them and out. to do this you have to have four nesting tubes. One of the tubes I had didn't quite fit, and if i remember right, I built it up with cardboard so that it would fit. In retrospect, I should have coated one side of a sheet of paper with elmer's glue, and then wrapped it around the tube until it was about 1/16" clearance on both sides of it. Then built it the rest of the way up with bondo for a strong smooth finish.