Propellers and Daisy Wheels display wind movement as do streamers, but not necessary at the same time. We have all seen them spinning and streamers hanging motionless or the opposite. For some it is comforting to see this movement of the flag and without some movement it is impossible to determine if the wind is activity. But a motionless flag is probably pointing at it’s last activity direction. This may or not be the best time or place to shoot. The larger and heavier they are, just like a flywheel are slow to start spinning and their inertia or torque affects how quickly they can slow or stop.
Propellers and Daisy Wheels have no ability to display actual wind intensity only the changes and not with a calibrated indicator. The larger and heavier object on the front of the flag is competing with the tail for control. The tail should be the primary wind direction indicator and it responds more accurately to clean air. Spinning objects located on the front of the flag act as “GRYO’s or Flywheels” attempting to resist and stabilize any movement from their current position and shielding the tail from undisturbed or direct wind flow.
An unbalanced propeller or Daisy wheel contributes to the jerking and twitching. I have seen statements about propellers or Daisy Wheel taking a hit or a blade being broken off and still working. Have you ever flown in an airplane with an unbalanced propeller and survived? Jerking and twitching caused by something turning while being unbalanced is not EXTREME SENSITIVITY. I cannot overstate the importance of a balanced propeller and Daisy Wheel or pinwheel. It is the only way to achieve accurate, calm and positive performance.
Some wind flags utilize spinning devices on the front, large direction indicator balls, streamers on the back of the tail. How many indicators of wind movement do we need? Each is fighting and competing for control. If you need to see something spinning on a wind flag there are many used by others. When a wind flag is displaying wind coming directly toward you the large Daisy Wheel or pinwheel hides much of the tail from view. There will have to be some movement to see where the tail is pointing. This could be only 10-15 degrees in either direction. Is that important to you? Placing the tail above the main shaft will help this situation.
Personally I find when four (4) or more flags are spinning, fluttering and streamers jerking, pointing at different directions all at the same time is distracting. It becomes a lot to comprehend and it must be accomplished quickly. This becomes even more difficult when the flag is overreacting. Just like your rifle and ammunition, your wind flag should be tuned for the best understandable performance. It needs to tell you only the one truth.
Is it mass confusion or are they all correct? Perhaps they are all both. It’s what the wind does. Only experience will provide the answer.
Several years ago MTC evolved away from spinning devices on the front of our wind flags in favor of more positive tail control and less needless activity.