RE: How does a Gyro work on Rudder Application?
Now that I am on my soap box.
Here are more of my old stories on gyros.
Hope you enjoy.
Twinman
Gyros on Twins...The saga continues!!!!
Recently I attended the giant scale fly in at our field with my usual
complement of twin engine planes. (OK, so I had to repair all of them after
the fly in....another story)
Due to a slight power excess, I was able to climb straight up with the best
of them. Maybe even do some of the maneuvers that the 3-D ships did. ( OK so
they are a "Little" better at smoothness, control, Gee whiz, etc.)
The one feat that they could do well, that I have not mastered, with a twin,
is the hover.
There is an inherent problem with conventional twins, in the hover, in that
the rudder is not in the direct prop blast of the engines. This drastically
reduces the rudder effectiveness. Yes, I have doubled the rudder in size to
better control engine out situations, but the hover is a real problem if the
plane yaws to the side. The rudder is not effective enough to recover. As
detailed in earlier sections of this series, the engines are already
electrically mixed into the rudder to aid the inverted flat spin and hammer
head, but the effect is a little bit too late and not effective enough for
this maneuver to control.
It is said, in the good book, that jealousy is a sin......Off to the
preacher with me!!
It is also noted that necessity is the mother of invention. ( The definition
of jealousy and necessity are so close, in the dictionary, as to be the same
as "Obsession") I hate to admit I can't do something.
I have done some small experimenting with gyros in the past . This gives me
an excess of these electronic wonders.
The plan was to risk my favorite plane, the converted Ultra Sport 1000 (
1002), to
once again go where fools know better. (Of course my son was all for it as
he likes a good crash)
As the engines were already mixed into the rudder on separate channels,
there are two separate leads from the separate channels going to the
throttle servos. Just what I need for the Hobbico Areo Gyro.
I installed the Hobbico Areo Gyro in series with the servo leads and
positioned the gyro to react to yaw. It takes a lot of gain in the gyro to
sense subtle movements on a large plane. It was positioned at approximately
the CG.
The idea is to have the engine on the down side of the yaw increase rpm and
the upper engine slow down to bring the plane back up to the vertical
position. This dampens out the yaw enough to react with the coupled rudder
and hold the vertical hover. Engines are coupled to the rudder.
I put the gain control on an off on switch, The gain was set at 90%, while
on, for maximum sensitivity. The gain setting was arrived (guessed) at by
wiggling a 86" plane in my workshop while my son watches the engine reaction
and tries to avoid getting hit by the gyrating mass of plane in a small
confined room. It is necessary to turn the system off for other maneuvers
such as flap spin, snap roll, hammer heads, and incase the whole idea "got
out of hand."
I also was not so sure about take off and landing. In the above maneuvers,
you can imagine the gyro would fight the necessary yaw dramatically.
To make a long story short, the idea WORKED !!!!
The plane is much easier to hover, and control yaw, using the gyro, to
assist the hover via differential engine thrust.
Note, the plane is capable of hovering at one half throttle. This is
important, as the gyro needs to be able to add more thrust with additional
servo movement on one engine and reduce the throttle on the other. Once
again, reliability on a twin cannot be over emphasized. Torque rolls are not
a problem, as the ailerons are more in the prop blast than are normal single
engine planes.
It was not a good idea to try a hammer head with the system on, as the plane
went nuts !! I won't try that again!!!
Loops were easier and more symmetrical, as were square loops. I, on the
second flight, I performed a landing with the gyro on, and it seemed to
track smoother. Take off with the gyro engaged is now much safer, as the
engines tend to come up together.
Don't do twins.....They make you crazy.!!!!