"RogerN" wrote in message
m...

"Stu Fields" wrote in message
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"Roger Haar" wrote in

Roger: You are dead right. On the Helicopter, the first move is to
track the blades. aerodynamically. Out of track blades on the helo will
cause a 1/rev vertical vibration that can confuse a balancing operation
if the operator isn't paying attention.
On our ship we put two different color grease pencil marks on each blade.
When the rotor is spun to full speed, my wife takes a pole with the
center cardboard tube from a paper towel roll attached to the top of the
pole and carefully brings the paper towel roll in until it just ticks the
blade ends. We get two different color tick marks of one blade is higher
than the other. We adjust until we get just one color combined from the
two. This doesn't guarantee good aerodynamic tracking at cruise speed on
the helo since aerodyanic differences of the two blades can cause a
"climbing" blade. Helps to have a fearless wife...


I do something sort of similar on my R/C helicopters. I use 2 different
color tape strips near the tip of each blade, hover the helicopter and
look at it from the side, you can see if one color of tape is flying
higher than the other. When the blades are out of track it causes a lot
of vibration.

RogerN

With our bigger ships, a tracking tip light was invented where you install a
red LED on one blade tip and a white LED on the other. The LEDs are pointed
at the pilot. The first time I tried these, I was nervous about them coming
off in flight and creating a hellatious vibration. While running up I
noticed a red streak and a white streak and thought "This is Great". Then
at flight rpm the lights disappeared. No vibration so they must have both
left at the same time. Slowed back down and there the lights were again.
Great design. Centrifugal force pulled the little battery away from the
LED. Tremendous idea though. It eliminated the need for a passenger
operating a strobe light to check track during cruising flite. One design
used centrifugal force to turn the LEDs on...