Please, some thoughts about counter-rotating props using
  twin Mazda power
  (one on each wing).

  In fantasy land, we turn the rotors around and run the
  Mazda backwards. I
  don't think even Paul could figure that one out.

  By the way, very nice article in June 2009 KITPLANES,  Paul.

  I've been unable to find a suitable reversing gearbox. So
  far, I've thought
  of putting a "sandwich" gearbox between the engine and the
  PSRU. I know
  this is easier said than done. You could probably use gears
  from an auto
  transmission. As each engine with the accessories has to be
  the twin of each other
  (except for the rotation part), both need the gearbox.
  With a straight-through arrangement you would need 3 gears
  (input, idler,
  output) for original rotation, and input, two idlers,
  output, for reversed
  rotation. For an offset arrangement, one idler can be
  subtracted from each
  gearboxe. Oil squirting barbs at all gear meshing points.

  Initial problems are the input adapters from the engine,
  and the output
  adapter to the PSRU.

  This is as far as I have gotten with my brainstorming, and
  I am sure that
  there is tons of stuff that I am missing, so please feel
  free to critique -
  something I have learned to value in reading your daily
  posts that I get in
  my daily email.

  By the way, the object of all this is a 60% P-38 in which
  rotary engines
  are the only ones that make sense for physical room and
  power. Also, it only
  works if the inside of the cockpit is laid out like a
  sailplane (recumbent).
  Thank you all, I have learned to enjoy your fearless,
  open-minded ways.
            Bernie.


  Why not just connecting the PSRU to the shaft on a modified
  endplate
  on the other side of the engine ?

  Philippe-Pierre DEJEAN


 Bernie,

 Nice part about the planetary gearing is reverse rotation is easily done.

 Ring gear, cluster gears, and sun gear.  Change the input and output for
 different gear rotation and ratios.  You want to match rpms on both
 sides, so it would be a different gear cluster.

 The 2.85 is sun to ring ratio. (same rotation).  So you need to
 find a Sun to Planetary gear that is the same ratio, which
 give counter rotation.

 Mind is slipping.... Was it the Ford Transmission that went
 with the six planetary gears (three being most common),
 but for a Diesel truck it went to six.

 Tom

    Bernie,

 Nice part about the planetary gearing is reverse rotation is easily done.

 Ring gear, cluster gears, and sun gear.  Change the input and output for
 different gear rotation and ratios.  You want to match rpms on both
 sides, so it would be a different gear cluster.

 The 2.85 is sun to ring ratio. (same rotation).  So you need to
 find a Sun to Planetary gear that is the same ratio, which give
 counter rotation.

 Mind is slipping.... Was it the Ford Transmission that went with the six
 planetary gears (three being most common), but for a Diesel truck it
 went to six.

 Tom Walter

 "So you need to
 find a Sun to Planetary gear that is the same
 ratio, which give counter rotation"

 That is the hard part :)

 Paul Lamar

Not talking about the availability, just strictly on the technical
aspect, it is like this:

For example:
Same direction of rotation:
ring gear      120 teeth   fixed
Idler gears     30 teeth  output +1
sun gear        60 teeth  input +3

ratio = 120 / 60 + 1 = 3:1


Opposite direction of rotation:
ring gear      120 teeth   output -1
Idler gears     40 teeth  fixed
sun gear        40 teeth  input +3

ratio = 120 / 40 = 3:-1 (in opposite direction)

Regards
Rolf Pfeiffer