koert42 wrote:So, one would think that the US patent on the Axis has already expired.Koert
Perhaps the earliest patents have expired. There may be others that were taken out later, and cover small but invaluable innovations that made the basic invention work in critical ways. The Axis-49 units have some nice and some subtle design features.
In any case, don't sweat the patents. They are intended (originally anyway) to keep a small but newly successful company from having their key invention (and other hard, expensive work, like marketing) swiped by another company.
If you can build a hand made unit for less than $500 and piles of time, please tell us how!
If you want to build them commercially, work with C-Thru - their knowledge and advice will be worth the licencing cost.
Note that you will be competing in a market that they have staked out and created.
Ken