George, Atkins is now using the Powersport internal ring gear psru. You
can check it out on the web at
www.powersportaviation.com .
It's a really nice unit though heavy, around 60 pounds. I do like the
arrangement in some ways. But it is high priced at $6,500.00! If I spend
this much on a PSRU I would buy the Mistral. Lighter and configured for a
hydraulic constant speed from the start. I had been in communication with
the designer of the PowerSport unit for some time. He was supposed to be
building a new unit that would handle more power and be lighter. He was
involved in auto work though and hasn't made much progress in over a year.
The one big advantage of the internal ring gear unit is that it offsets the
e-shaft centerlind about 3 inches lower. That lower e-shaft center line
makes it much easier to wrap the intake over the engine. PowerSport has had
some money problems so I don't know what the current status of the company
is. If I was to order from them I would probably request a escrow account to
prevent getting into trouble.