Why is it important when dealing with flex plates?

   http://en.wikipedia.org/wiki/Moment_of_inertia

   "In classical mechanics, moment of inertia, also called mass moment of
   inertia, rotational inertia, polar moment of inertia of mass, or the
  angular
   mass, (SI units kg·m²) is a measure of an object's resistance to
changes
  to
   its rotation. It is the inertia of a rotating body with respect to its
   rotation."

   Also read gyroscopic forces.
   http://www.gyroscopes.org/behaviour.asp

   "When the gyroscope is spinning it can contain large amounts of stored
   energy. Newton's first law of motion states that any body will continue
in
   its state of motion (still or traveling) until outside forces change
it.
   Because of the forces when the gyroscope is spinning, if it is moved
the
   gyroscope will try to 'compensate' for this movement. If we take the
  example
   of a gyroscope's axle being clamped to the structure of the car (often
the
   cars engine behaves as a gyroscope because of its shape, mass and
   rotations)."

   "If the gyroscope/engine is spinning at a fairly high speed in a
clockwise
   direction, as seen from the back of the car and as shown in the diagram
   above. When the car is turned to the right (clockwise from above)
forces A
   and B are applied to the structure of the car forcing the front end of
the
   car down and the back end up. If the car is turned to the left then the
   front end of the car is forced up and the back end forced down. If the
   gyroscope is spinning in the opposite direction then the reverse will
   happen."

   "However if the car was moved directly upwards, downwards, forwards,
   back-wards or side-to-side the gyroscope would not apply any extra
forces.
   The gyroscope only applies extra forces when the car is moved at an
angle
   (turning left/right or when the front/back of the car is moved
up/down).
   This effect is known as gyroscopic precession."

   These forces go through the flex plate out to the ring gear stressing
   the flex plate back and fourth near it's hub thousands of times per
  minute.
   In other words the ring gear attempts to continue to rotate in it's
  original
   plain while the hub is being forced to change direction.

   Paul Lamar

  It is interesting to note that most of us have a gut-feeling for the
  nature of linear-momentum. Its value is calculated as the product
  Mass x Velocity, which is quite logical. As the mass of an object
  increases, so does its momentum (3 times the mass, 3 times the
  momentum). The same is true with velocity (3 times the linear velocity,
  3 times the linear momentum.

  But with angular momentum logic and gut-feelings often fail to account
  for the implications of increased angular velocity [RPMs] on the forces,
  the momentum, and the resulting gyroscopic forces.

  Centripetal (ie centrifugal) Force depends on (Mass x
  VelocitySquared)/radius. Or if one is thinking in terms of RPM ...
  Force = Mass x Radius X Square of (6.28 x Rate of Rotation). The
  relationship is not linear, and most people (like me) are linear
  thinkers. The forces on your flex-plates and such go up with the square
  of the rate of rotation. Three times the rate of rotation=9 times the
  centripetal force.

  With Angular Momentum we also have a non-linear relationship. Angular
  momentum of any rotating solid is calculate by thinking of each solidas
  an infinite collection of rotating points, with each point having its
  own Angular Momentum calculated by Mass x Square of Radius of Motion.
  Adding up all these infinite little Angular Momentums requires using
  calculus or a computer ( or a formula for regular solids derived using
  calculus). Since my calculus is a little rusty, I will just say that
  logic fails most of us here. For any given rate of rotation, Angular
  Moment depends in some way upon the square of the rotating object's
  radius. Add the fact that as Paul mentioned, the gyroscopic forces are
  exerted at 90 degrees to the axis of rotation and 90 degrees to any
  disrupting rotation and my brain goes fuzzy on me.

  So if one wants to minimize gyroscopic stresses on a spinning wheel,
  keep the radius small and the mass low.

  But then there are trade-offs, because we want a large radius and large
  mass if we desire inertia for the "flywheel-effect" in pulse-dampening.
  There is no free-lunch I guess.

  Robin

  It seems to me we don't have an issue with Tracy's damper but with the
  Mazda flex plate. The only function the flex plate serves for us is as a
  mount for the ring gear for starting the engine. If this is the case
perhaps
  the tree to bark up would be investigating further the concept of
  starter/generators and eliminate the starter, ring gear and flex plate
  altogether.

  John
  (OK what did I miss ?)


  Way too ambitious. Given up on by major companies.
  The problem is it takes 3 HP to start an engine.
  There are two ways to get HP. Use a large low RPM motor
  with high torque or use a small high RPM motor with a gear box.
  The second choice is embodied in the current starter.
  The first choice results in a heavy motor with poor
  power to weight ratio. Hybrid cars.

  Paul Lamar

Hi, there are motor/altinators on the belt drives of some cars/trucks,
mild hybrids with idle engine stop. Some hybrids have flywheel
motor/generators. Perm magnets in the flywheel and stationary coils in the
housing, electronically switched. Could be the most reliable system.

Murry I Rozansky

They are very heavy and large. They also have so much torque they can
move the car
in city traffic.

Tracy and other's sell gear box adapter plates that accept standard Mazda
starters.
Installing most of these ideas takes more time to complete the engine
installation.
Not a good idea. Extra time for installing a rotary is one of the largest
drawbacks. We are trying to make it simpler, quicker  and easier unless
there is a major
problem with a stock part. If it is not broke don't fix it.

Paul Lamar

   The simplest fix is a rigid flywheel, a flex plate unsupported by a T Q
and the gearbox's shaft will flex.
   If you reinforce the flex plate so the deflections are under control
you can still call it a flex plate, it is OK with me.

Murry I Rozansky