"Alan how do know that patents in most non-US countries don't cover manufacturing? And does that matter to most posters on here who do happen to be in the US?"
I looked it up. I don't live in the US, and were I live that is the case, and it would appear other places too.
"And for what seems like the billionth time, there are plenty of legal myog projects. This one started with linking to and praising a guy that is giving you a blue print to infringe an existing patent."
It would be appear that might be technically the case (ie illegal) in the US, although it sounds like it is essentially unenforceable there, but is not necessarily illegal elsewhere. In my view companies get patents as a defence against other companies not a few MYOGers.
"What is a shame is that you are ok with somebody getting ripped off."
I resent that.
MYOG frustums are not a rip-off, whereas selling a replica caldera cone would be, and I would definitely oppose that, irrespective of any patent.
Infringing the Trail Designs patent for MYOG (and I not sure if the script generated frustums do: lawyer(s) etc required for that) might not be technically legal in the US, but otherwise its no different from any other MYOG. MYOG is normally a friendly collaborative activity, and Trail Designs have been friendly to the MYOGers.
I think selling copies of patented items commercially is wrong (as well as illegal), as patents are a deal: in exchange for making their design public, the patent holder is offered a commercial monopoly for a limited period. Even with no patent I think most people would choose Trail Designs over a commercial clone, and so would I, but MYOG is OK, and if legal in your region, it is no different from any other MYOG.
Note I bought a cone first, I like the product, Trail Designs is successful, they are a nice company, if anyone asked about my homemade frustum windshield, I would mention them.
However, I think the US patent laws are wrong to include MYOG as an infringement (even if not enforced) that is not purpose of the patent "deal" described above, but I don't live there.
A frustum windshield is a simple idea, after that the postscript generated stoves deviate from the real caldera, so the "caldera clone" isn't actually a clone, its a snappy title for the original forum thread: perhaps "Caldera Tribute" would cause less grief whilst retaining a good will pointer back to Trail Designs).
"Nobody is acting like a rival company is setup"
A few MYOGers aren't a threat to Trail Designs, a rival company would be.
In my view companies get patents as a defence against other companies not a few MYOGers.