Wind flag disasters

mks said:
Rick,
Having watched them at a number of ranges in my area, your flags are indeed stable. In your experience, what is the key to achieving stability in a balanced flag? Is it, as Wilbur observed, having a long enough tail for "leverage?" If one keeps the flag balanced, adding more tail means more counterweight must also be added. The extra weight tends to increase inertia, which decreases stability. Is the effect of the extra leverage greater than that of the extra counterweight? Seems that way with the flag ideas I have played with.

Thanks,
Keith
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I think Wilbur is right that if a flag has design issues balancing them heavy to the tail end can help somewhat, but at the same time may create other issues… like putting the pivot in a bind. ( unless you have some sort of elaborate bearing set up in your pivot) Also unless you have your stands perfectly straight up and down a tail heavy flag will give false readings in low wind conditions… the heavy end will always turn to the low side. (unless your binding pivot won’t allow it :) )

As far as my feelings about it, I agree with Boyd Allen in his post earlier in this thread. He has obviously spent some time thinking about these issues.
 
RJG said:
I think Wilbur is right that if a flag has design issues balancing them heavy to the tail end can help somewhat, but at the same time may create other issues… like putting the pivot in a bind. ( unless you have some sort of elaborate bearing set up in your pivot) Also unless you have your stands perfectly straight up and down a tail heavy flag will give false readings in low wind conditions… the heavy end will always turn to the low side. (unless your binding pivot won’t allow it :) )

As far as my feelings about it, I agree with Boyd Allen in his post earlier in this thread. He has obviously spent some time thinking about these issues.
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Like I said, your, or anyone else's flag that is perfectly balanced by center of gravity, will not be balanced the same in use due to drag. So, yours are binding too!
Trick is, reduce the weight and friction of this bind to a point where it's a non-issue. It can be done. I recently had a flag on a tripod inside my shop when a friend and fellow shooter came in. The flag was turning and the pinwheel was spinning from the air currents inside my shop. He jokingly asked if I had made them battery powered. Must not be binding too much on mine. They move with surveyor tape, and before sail tails, but the tail also offers leverage and more stability...holding the flag back, if you will.--Mike
 
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mwezell said:
Wilbur, this is simply not true. For a flag(or plane) to be stable, the center of pressure must be behind the center of gravity. This is evidenced by how a plane gets loaded with cargo. Again, how you get there is another subject. Google and aeronautical engineers are my friends.:)
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Mike,
I think you and Wilbur are saying the same thing here. More tail area versus nose area moves the CP toward the tail.

Cheers,
Keith
 
mks said:
Mike,
I think you and Wilbur are saying the same thing here. More tail area versus nose area moves the CP toward the tail.

Cheers,
Keith
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Keith, after re reading his post, I think you're right. Wilbur, I apologize.
Fact is, there will be some amount of friction, even in the best case. I don't consider some amount of friction as a deficiency in the flag design..if everything that can reasonably be done to minimize it is addressed. My design excels here. But I stand by my statement that a perfectly balanced flag in a static state is NOT perfectly balanced in a dynamic state. So minimizing THAT friction is where it seems that Rick and I are in some disagreement. It seems that he is saying that his flags don't have this friction in either state, which is false, regardless of how the flag is balanced, at different wind speeds due to varying amounts of drag. Again, Rick, you have a very good flag and this isn't meant to be a pissing contest, just adding to the conversation of flag design, and if we disagree on some aspects that's fine.
 
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It seems to my inexpert mind that the real issue is what happens in really light conditions, where any bind force would be minimal. When the wind is blowing with more force, tracking is not much of an issue.

IMO the best way to resolve any issues of the merits of different designs is to put both out and watch how they respond to the same conditions. This is how I decided which of the many combinations that are possible with my Hood "kit". (regular vanes, big vanes, daisy wheel shaft, no daisy shaft with weight for regular vanes, no daisy shaft with weight for big vanes, weight/retainer to be used with daisy wheels, daisy wheels, heavy ribbon, surveyors' tape, and various amounts of counterweight and daisy shaft extension, with and without the daisy.)

I still have to make some sort of bullseye level adapter for setting my pivots vertical. Truthfully, when conditions are light and switchy, most of my attention is on the surveyors' tape. It is the early responder.
 
Mike, sorry about that, but I think you may have misunderstood what I wrote. (that never happens on the internet does it? :D) I was speaking in generalities, not addressing your flags at all which I would not consider my place to do. My only purpose for speaking up was to let guys know that the “balance them tail heavy” idea doesn’t apply to Graham flags.
 
Boyd, you hit on something else that will dictate friction on the sides of the pivot, and that's that unless the pole is very plumb, you have side friction. I agree with comparing flags side by side,too, and I've compared to most if not all of the widely used and reputable designs. Testing with smoke is interesting too. When testing side by side, one should remember that a 10 mph wind is moving at about 15 fps, so set the flags close and keep in mind that one SHOULD move before the other in this respect. It's something I've come to enjoy, testing flags side by side. You can really learn a lot by spending this kind of time with your flags, aside from match situations.---Mike
 
RJG said:
Mike, sorry about that, but I think you may have misunderstood what I wrote. (that never happens on the internet does it? :D) I was speaking in generalities, not addressing your flags at all which I would not consider my place to do. My only purpose for speaking up was to let guys know that the “balance them tail heavy” idea doesn’t apply to Graham flags.
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Rick it applies to any flag or plane or whatever. The center of pressure must be behind the center of gravity to be stable...meaning it will stay in, or quickly correct itself in the wind without getting "confused", for lack of a better term. More sail moves the cp back but does so at a price, that being more weight, causing reduced sensitivity or slower response time. What happens if you move the pivot way rearward making it nose heavy?
 
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mwezell said:
Total weight of my flag, with sail tail attached is about 126 grams.
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Since you gave the weight of your flags, I had to weigh mine to see how they compared. I have made some changes since you saw them last. The cylinders are now concentric with the pivot, and the counterweights have been eliminated. We'll see how they work tomorrow.:confused: The 8" diameter are 76 grams, the 10" are 96 grams and the new 12" are 142 grams. The styrofoam is still fairly thick. I think I could go maybe 30% lighter. I am with you on the value of light weight. And Boyd makes a good point about keeping the weight as close to the pivot as possible.
 
Ladies and Gentlemen. As always Thank you for sharing......
Very interesting.......Pls use Austrian accent.

Now this thought. Opinions only........
Does the human being/shooter compensate for all the frailties/issues to the wind flag designs.....?????
Ie. Maybe some shooters read them better than others......

I have an issue/problem. A friend(he is married to my sister's friend. Which we didn't know for 4 yrs. and was over 30 yrs ago. It is a small world.) has won 4 score matches in a row. Came down to the last shot. Which was not his.
The first match was his first time at that range.....Good thing. He joined the club.
This shooter does not use any flags.
Do you think there is a thing in your brain that says when and where to shoot......?????
 
zippy06 said:
Ladies and Gentlemen. As always Thank you for sharing......
Very interesting.......Pls use Austrian accent.

Now this thought. Opinions only........
Does the human being/shooter compensate for all the frailties/issues to the wind flag designs.....?????
Ie. Maybe some shooters read them better than others......

I have an issue/problem. A friend(he is married to my sister's friend. Which we didn't know for 4 yrs. and was over 30 yrs ago. It is a small world.) has won 4 score matches in a row. Came down to the last shot. Which was not his.
The first match was his first time at that range.....Good thing. He joined the club.
This shooter does not use any flags.
Do you think there is a thing in your brain that says when and where to shoot......?????
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I don't know, zippy. I do know that we go to great lengths and spend lots of time and money to make our equipment the best we can. After all of that we find that our equipment is at least as good as anyone elses. It wouldn't make much sense to go to those lengths only to put out flags that we knew were not of the best quality we could justify. Wouldn't that be like shooting a bullet that we knew wasn't the best in our gun?
 
mwezell said:
Charles, thanks for yet another post of such great value.
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Think it through, Ezell. Even if you can't use them during a match -- & I don't see why not, save fire laws -- I think smoke is valuable for testing.

You're flags are twitching -- "see how sensitive they are?" you think? But the smoke doesn't show it. Either (1) smoke's no good as an indicator, which runs counter to my experience, or (2) it's back to the drawing board, because the smoke is showing you've left something out of your physics.

In short, it's silly to test a device against a similar design to discover what's better unless you've confirmed the you're onto something.

But maybe not, as you say, I'm wrong a lot.
 
Charles E said:
Think it through, Ezell. Even if you can't use them during a match -- & I don't see why not, save fire laws -- I think smoke is valuable for testing.

You're flags are twitching -- "see how sensitive they are?" you think? But the smoke doesn't show it. Either (1) smoke's no good as an indicator, which runs counter to my experience, or (2) it's back to the drawing board, because the smoke is showing you've left something out of your physics.

In short, it's silly to test a device against a similar design to discover what's better unless you've confirmed the you're onto something.

But maybe not, as you say, I'm wrong a lot.
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Charles, I didn't link witchcraft and smoke when I read your post. Plumbing supply stores carry industrial smoke bombs that are rated in minutes. They work great and were more available where I'm from than smudge pots and witchcraft items. You can also use an old coffee can to make something similar to a bunson burnerto produce smoke for several hours. My flags aren't twitching and respond wonderfully. As a matter of fact, better than any flag I've tested or shot over. And according to a friend,no two friends, that are in the aeronutical industry, and are engineers in this field, the physics that applies here, and that I've been trying to convey, is correct. If you go back and read my posts,
You'll see where I mention using smoke to test with as well as my point of physics, where I clearly state my position, that the cp must be behind the cg for the flag to be stable dynamically. I stand by that as being true, and that this can also be achieved with a lager vane, that simply moves the cp backward but at the expense of added weight.
 
Smoke has been used by aerodynamicists to study airflow since the very beginning of the field. Anyone that doesn't think it is a useful tool is simply misinformed.
 
SGJennings said:
Smoke has been used by aerodynamicists to study airflow since the very beginning of the field. Anyone that doesn't think it is a useful tool is simply misinformed.
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Yes Greg, I agree. Smoke comes about as close to real time as we can get and certainly is a good indicator to compare against. It's interesting to watch how the flags respond compared to the smoke. No doubt, it'll let you know if something is wrong with your flags. I have tested different tail materials as well. Mylar or strips of plastic shopping bags are very light and sensitive, but they tend to overreact in anything more than a very light breeze. Surveyor tape is a tad heavier but still suffers from the same issue.
Honestly, if surveyor tape doesn't move, I'm shooting unless the sighters say otherwise, but I would prefer to have a steady and "honest" push all the way down and across the range most any time. The pinwheels on my flags, as you know, begin to churn at about the same time as surveyor tape begins to move. This is in part why I like the sail tails. I can rely on the pinwheel to move for the very light winds, and when the wind is blowing like it does 95% of the time, the sail tails are moving to some degree and don't max out nearly as soon. I also much prefer the linear feedback they give me opposed to the fluttering surveyor tape and other light materials. I completely understand people that don't use garden daisies. The damn things won't move in light wind and won't stop in a switch until it may be too late. That's why the very light design of my pinwheels and the teflon pivots they spin on are superior by far to any daisy I've seen. And the two colors show angle changes almost instantly. That's just something you have to see for yourself to appreciate if you're use to standard daisies or balls.
 
"The one issue that I have left to resolve is a way to have my pivot shafts perfectly vertical."

A couple years ago - I had the students in my HS physics class do a project on wind flags (response time, repeatability, accuracy, stability, etc) We video taped everything from above the flag. To make a long story short, having the pole plumb made a difference on all the data recorded. The data was plainly visible from the video tape - but I don't know if it would be visible by the shooter looking at the 60 yard flag, etc. Regardless, I now use a 2" long piece of 3/4" delrin with a bubble level glued on top that fits over the flag pole head to let me know when it is plumb when setting flags. Might help - doesn't hurt.

Stanley

Added: One thing that always interests me is the fact that we are only "seeing" a small fraction of the wind - yet many shoot extremely good. Assuming the windflag is 1/8" thick and we use 4 flags at 100 yds - that means we "see" a half inch of the wind over 3,600 inches = .014%. We are assuming the other 99.986% is doing the same thing. Maybe that explains why shooting in the "calm" is so dangerous and usually results in a flyer somewhere. Having some wind seems to "level" that other 99.986% out.
 
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Jason,
What a neat project. I would be interested in the results if you have them.

Thanks,
Keith
 
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