Mark sent me a private mail on this subject. I thought that rather than responding privately, I would cover the salient points here for everybody.
It was very thoughtful of you to consider whether or not you
were infringing on our intellectual property and contact us to make sure. Yes, we applied for the patent for our Caldera Cone over 2 years ago and expect it to be approved soon-ish. Patent Pending comments are sprinkled around the website and are now being stamped into the cone itself. Let me know where on the website you were looking and I can add it to that area as well. We have devoted a lot of time, money, tooling, and design expense to develop the Caldera system. While we would prefer people respect our efforts and not publish plans to copy our system, we also come from the same community as you and expect a certain amount of curiosity. So long as DIY efforts are directed toward personal curiosity....and not general or commercial gain....I doubt we will have many issues.
Now, to the beer can Caldera. So you know, we have been developing this for a while and prototypes are currently in the field being tested. I am including pictures of an early version below....our current model has evolved from this a bit. As you can see, on this prototype we chose a slightly different design parameter over Mark.....that is for more of the Fosters can to be inside the cone while cooking, at the expense of the cone sticking up a little taller in the packed state. Also, the dovetail closure has a larger "handle cutout" than normal because of the geometry issues dictated by needing to feed one dovetail into the other. As I mentioned, these variables have been tweeked somewhat and our latest design packs more into the can and the dovetail cutout is less severe.
Our ultimate plan is to have a kit not dissimilar to what you see here that includes the Fosters can, Caldera Cone, lid, stove, and fuel bottle. Still playing around with the cozy and packaging options....and how best to source large quantities of Fosters cans. In the mean time, we would be happy to make our latest version of the cone and stove available to BPL readers in support of your DIY projects....you work up how best to build the can, lid, wicking, packaging etc.....and we can work a deal on the cone and stove.
Let me know if there is any interest in that, and I'll work up some sort of deal with my partners and let you know!