Any idea what is the total number of hours and how much pocket change ?
Well, the transmission has about $65 worth of extra parts in it that a direct drive don't have - namely an extra shaft, two extra bearings, two sprockets and the drive chain. The rest of it is pretty much a wash because you still have to have one set of bearings, stator support and on and on to build a turbine anyway.
Being the case is integral with the yaw tube and tail mount, it's just basically 5 pieces of sheet steel torched out of a sheet of 1/4" and all welded together to make the case. The cover is made out of a piece of 3/16" sheet steel.
The generator has roughly half the wire in it that a direct drive would have, and 24 2 x 1 x .5 N42 bar magnets instead of 32 2 x .5 disc magnets. I figured the savings in magnets alone at about $175, depending on where you get them from. The generator rotors are 10" diameter instead of 16". And the stator is 14" OD instead of 20", and only .450" thick instead of 5/8". You can get away with the very thin stator because the diameter is small enough that it won't warp and come into contact with the rotating assembly when you start applying serious torque to the mount.
It cools better because it has less wire mass to retain heat, is thinner, and because the generator rotors are spinning at such high speed without the magnets being encased in resin, the rotors become centrifugal fans. Those rotors move a LOT of air over that stator at 600 rpm. I had absolutely no overheat problems testing on the stand at 80 amps for an hour because if you tape a piece of paper to the outside perimeter of the stator that paper stands right out on end from the air blowing over the stator.
So there's a number of advantages that I see here.
I never figured any of the costs to the penny, but it was cheaper to build this geared unit than it would have been to build a direct drive, with most of that cost being in the generator. The downside is that it takes more work and some basic machining to build it. At the minimum, unless you get your parts waterjet or plaz cut, you'll need a lathe, vertical mill and drill press to build one. I have all that stuff, but if you had to hire it done, then the cost would go up because machine work does not come cheap.
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Chris