Heron, The Autoflight gearbox is superior to other designs as well as using first class materials, the input shaft design is novel. It was patentable when I first designed this system but didn't because it would add cost and this is a small niche market, hell who would bother copying it. There is no loose joint from the crank to the output shaft to move or fret only gear clearance. The rubber drive takes care of the "normal" engine pulses. There would be over 400 units out " doing the business " over five years ( Autoflight Ltd ). So it would seem it is worth copying, I would have at least thought these people would have contacted me to discuss a license deal. As you will see from another post here ( where the china copiers are copying the Zenon ) they actively hid from Autoflight hoping to get to the market before I noticed. We don't have snakes in NZ but china does. Interesting enough there are rules about selling direct copies in Australia and in NZ, patented or not. I am using Trade and Enterprise to investigate having these copies stopped from sale in these countries. In the future I will now have to look into protecting my intellectual property.