GYRODYNAMICS

Have noted ongoing happenings among all you people which narrow down to about basic 3.
Point is these items were uncovered and cured during our R&D which resulted in the Giro V all of
which was detailed in the 2/2000 RCM
Perhaps that is to far back so will breifly report the 3 once more.

1...Stability> maximum stability was found with winged versions ala the early Kelletts etc.
Similiar results were seen with "forward vertical stabiliers" ala as used on Giro V which had
a wing-like seperator for them. Later the "Wing" was replaced with a metal arrow shaft and
performance remained the same.
With wing less Gyros it is a help to have additional forward lateral area, usually as with the
rotor pylon.

2...Airstream Force> one would seldom consider the magnitiude this force presents and that
easily can collapse rotor control linkages and overcome servos.
The force magnitude increases with increases in rotor disc frontal area and with flight speed. Increases are as of a square of the speed and quadruple area increases
Often the problem is seen in flight as changes in circumstances cause the rotor to move full back and be held there.
Solution was to use very robust control linkages, rotor head and a minimum 120 in oz servo
with metal gears.

3...Gyro tilts on take off at lift off time> this factor is common to all autogyros and is labeled
"retreating blade stall" or techniucally a lift differential.
Fortunately the factor is only present during a small portion of the rotor rpm spectrum starting
just before lift off rpm is attained and ending as flight RPM is achieved.
Full scale solution to this problem is to power up the rotor the flight RPM before commencing
take off. The method is called "Pre Spin"
This factor was added to model Gyros and with it hundreds of flights have taken off with no aborts.
Method is to adapt engine starting routine to the rotor. Rotor is equipped witth a propeller spinner and rotor is pre spun ala an engine with a 700 RPM B&D portable hand drill motor.
Note that flight RPM commences at about 350 RPM>
Further note that determining Gyrodynamics at first envolved crashs and rebuilds. A better solution was found using a "car tunnel": The Gyro is attached to the hood of the car and action can be observed at various speeds.
Again, hopefully info will be helpful to many. we need all the Gyro people we can get?
And please don;t forget> Autogyros over Spring Hill February 22-23, 2005
Good luck!

Hal [email protected] .