This Instructable is going to guide you through the critical steps to create a CAD file for 3D Printing a Cryptex. It will use Autodesk Inventor 2012, and will detail the critical steps needed to create it. Basic experience with your CAD software of choice is recommended. This should include creating parts, assemblies, extruding, cut extruding, revolving, embossing, and basic parametric modeling skills. If you are interested in making an exact copy of my Cryptex, please skip to Step 17, which details modifying my files to edit the combination.
IF YOU ARE CURRENTLY SEARCHING FOR, OR PLANNING ON SEARCHING FOR, THE GEOCACHE CRYPTECH (GC3K7QE); YOU SHOULD BE FOREWARNED THAT THERE ARE SPOILERS INCLUDED IN THIS INSTRUCTABLE.
Step 1: Dimensions
> Number of Letters in your combination (I used 6)
>Outside radius of the rings (This dimension is not critical, I just used it as a reference point. This dimension gives a target point for all of the other ones.) This will give you an approximation of how large your cryptex will be.
For my cryptex, I wanted a fairly large cryptex, with easy to grip dials, easy to read letters, and an easy to access compartment. I wanted it large enough to fit into your palm, but not small enough to fit easily into a pocket.