Vigilant,
One of the reasons that I am working on this design is to update it to a ratio better fitted to available props. The reason for purpose built is so that you can build a unit that has the ability to adjust the gear lash, which helps greatly to prevent the torque reversals that force many of the planetary units to idle so high, and puts all the torsional vibration orders out of the RPM range. That is "why." The question is totally reasonable though. The use of OTC transmission planetary gear sets requires that in addition to idling sky high there is a large end thrust to be dealt with because of the helical gears. Used more for quiet operation than strength. I have seen the end thrust of one of these planetarys turn the thrust bearing blue when high HP was used. There are some with hours under their belt but at much reduced power output. For aircraft we must design our engine gearbox combo like a race car that will face an hours long flat out straight-away! Anything less than a 100% duty cycle is hazardous. BTW you are totally correct that the field is littered with failures, partial successes and backyard efforts, that while well meaning, may get people hurt. I want to see this system remove one of the obstacles home builders face. I also want to have a unit for my own plane, which will run a 3 rotor. As to cost, it is hard to estimate without some kind of idea of what the customer base may be like. There can't be a huge number of people just waiting for this to come along. I have built and sold products for the Motorcycle market, which is small, and this is likely to be even a smaller market that that. That is the reason for my troll like first post. I wanted to see how many people would even respond. That can give me some idea of number of people interested. If modern production techniques can hold the cost down I'm sure more folks might become interested. I am not fooling myself that this will be some kind of big business enterprise. If I could just break even, or only pay for my own parts it would be OK. Many of the parts are out for quote now and I won't be shy about passing the info along. I'm working with one of the originators of the system and he wants me to keep all his work from being lost. He is also most adamant about only offering it for sale if flying in a airplane that is fully sorted and ready to prove to the builders that it is good to go. For Ross's benefit I should mention the gearbox would be easily set up for other engines including a Subaru. Only 2 or 3 parts need be changed.
Bill