Gyroscopic Stability

Apollo

Apollo

Jason Stanley
We started our class project (testing different wind flags) today. One individual (who belongs to this forum) suggested we study gyroscopic stability concerning the daisy wheel. Some of the flags do have daisy wheels, others do not.

What the students came up with for their hypothesis on this section was: The faster the daisy wheel spins the more stable the windflag becomes. Translation to our topic; harder the wind blows = the faster the daisy wheel spins = less likely to pick up changes in wind.

We are designing our equipment to test different items concerning wind flags - so won't actually test them for another couple weeks. I was wondering what some of you engineers, and others with experience designing windflags, thought of this hypothesis and if we are even close to heading in the right direction?

Thanks

Stanley
 
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Interesting

Will be interesting to see the results and if there is proof to these questions, thanks for your efforts
 
Apollo said:
We started our class project (testing different wind flags) today. One individual (on this forum) suggested we study gyroscopic stability concerning the daisy wheel. Some of the flags do have daisy wheels, others do not.

What the students came up with for their hypothesis on this section was: The faster the daisy wheel spins the more stable the windflag becomes. Translation to our topic; harder the wind blows = the faster the daisy wheel spins = less likely to pick up changes in wind.

We are designing our equipment to test different items concerning wind flags - so won't actually test them for another couple weeks. I was wondering what some of you engineers, and others with experience designing windflags, thought of this hypothesis and if we are even close to heading in the right direction?

Thanks

Stanley
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Tell your students that they're RIGHT :)

GOOD on 'em ;)

Everything in this ol' world is a tradeoff and this is the downside of the daisy wheel.

I hope you do get the attention of some of the great flag builders on this site because the ensuing conversation will be enlightening. I'm only a user, not a designer. I currently set out only one daisy and that only because it's hooked to a potentiometer which gauges relative wind speed changes. EVEN THEN it's of limited utility due to the fact that the wheel is so heavy that it reacts slowly due to its own inertia..... a Beggs Wind Probe will bounce twice in the time it takes for the daisy to register a letoff and my balanced non-daisy flags will often switch end-for-end before the sluggish daisy gets its bearings.

A spinning daisy with one off-color vane is sure nice though for fairly steady winds. I find daisy wheels to be "easy" to get a feel for...... I like 'em.


There, maybe now some real flag guys will step in and comment :)

LOL


al
 
Apollo

Will you be testing the different types of pivoting ideas used in relation to stability?or twitchyness:D thanks Jim
 
Apollo said:
We started our class project (testing different wind flags) today. One individual (on this forum) suggested we study gyroscopic stability concerning the daisy wheel. Some of the flags do have daisy wheels, others do not.

What the students came up with for their hypothesis on this section was: The faster the daisy wheel spins the more stable the windflag becomes. Translation to our topic; harder the wind blows = the faster the daisy wheel spins = less likely to pick up changes in wind.

We are designing our equipment to test different items concerning wind flags - so won't actually test them for another couple weeks. I was wondering what some of you engineers, and others with experience designing windflags, thought of this hypothesis and if we are even close to heading in the right direction?

Thanks

Stanley
Click to expand...

Yes a guy in Australia figured that out years ago and makes wind flags with no daisy wheel and special joints that indicate the slightest wind from darn near any direction. Even near verticle winds . You are definately heading in the right direction .
 
Hi Jim. The stand that I am using has a 1/4" OD male end. The flag will sit on top of that. One of the flags has a male end on it and Steve G machined a female end that fits over the 1/4". I'm using the same stand for all flags. So...whatever rotational device the flags has in it will be tested - if not (such as one of my flags - it just rotates on top of this 1/4 male end) then I guess I can't really change that. I'm hesitant to name names of the flags.

The students are loving this project. I gave the class 3 choices.
1 = wind flags
2 = wind tunnel
3 = grain launcher for pheasants in the winter. 3 boys wanted to launch something.

The students that volunteered for the wind flags are 7 females and 1 male. Only 1 of the students has ever shot a rifle. We are going out after school to shoot one of these days. Start out with a 22 then move to a 22-250 - then I'm going to let them shoot my 260 AI. I have to fireform some brass - might as well let them pull the trigger.

Thanks for all your help

Stanley

Thanks for all the input
 
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I have a question and potential variation on the hypothesis:

I believe that velocity of the flag spinning is one significant factor in responsiveness to a variation in wind direction, but that the weight of the spining wheel may be even more significant to its responsiveness, meaning if two wheels are of the same size and are both spining at the identical velocity, but one spinning flag weighs more then the other, the lighter wheel wll be more responsive to the slight variations in wind direction.

Does that make sense?

JeffVN
 
Yes it does make sense. Inertia and momentum go hand in hand. If two daisys have the same velocity but one is heavier - it should take longer for the heavier one to "want to" switch.

That would be a pretty easy thing to test - I'll add that to our list.

I'm guessing the same thing is true with the actual vanes themselves. However, not sure how much of a difference it will make. The shooter still has to be able to read the flags.

I'm already starting to see that there will be certain trends for what you want in your flags. If you want a super sensitive one then their will be certain characteristics in your flag vs one that is not so sensitive. (I think there was a thread about that topic earlier)

Thanks again for all the advice.

Stanley
 
J. Valentine said:
Yes a guy in Australia figured that out years ago and makes wind flags with no daisy wheel and special joints that indicate the slightest wind from darn near any direction. Even near verticle winds . You are definately heading in the right direction .
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Would electronic wind instruments be allowed in benchrest competition? Perhaps a couple of ultrasonic anemometers with a PC to calculate bullet defelection directly in real time. Or a scintillation anemometer which doesn't requires any dowrange equipment to give two dimenstion wind information over the entire trajectory. It wouldl be a scaled down version of the instrument used on Abrams tanks. It's just an optical device to mesure air movment simiar to a human watching "mirage" but with high precision amd speed.
 
JeffVN said:
I have a question and potential variation on the hypothesis:

I believe that velocity of the flag spinning is one significant factor in responsiveness to a variation in wind direction, but that the weight of the spinning wheel may be even more significant to its responsiveness, meaning if two wheels are of the same size and are both spining at the identical velocity, but one spinning flag weighs more then the other, the lighter wheel wll be more responsive to the slight variations in wind direction.

Does that make sense?
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Unless the hypothesis was misstated, I take yours to be the correct interpretation. The inertial resistance to changes in the wheel's rotational velocity would be due to angular momentum, not gyroscopic effect.
.
 
What I want is the wind flags that wireless transmit the wind data directly to the scope and servo motors make the correct allowance for a presett range.
Dream on baby ?
While I am in la la land , also an intergrated laser ranging system that automatically allows for elevation at any range you put the cross hair on and push a range enter button.
Would have to sell my house to buy one.
 
the stability has nothing to do with gyroscopic stability. your simply looking at mass VS surface area of the wind flags.
 
what about the number of vanes, diameter of the "daisy wheel" compared to the size of the vane? Also the pitch of the vanes on the daisy wheel?
 
Jason, if you're interested in having the class test an extremely light weight daisy wheel, let me know and I'll bring you one next weekend at the first annual 'Beresford Benchrest-BBQ-Movie One Liner event.

Nice going getting the kids involved. :) -Al
 
gday jason

have you thought along the lines of a wedge type vane the one i made seemed very responsive and self dampening just another thought good luck with your findings and thanks for the info jim:)
 
It is kinda cool how this thread "popped up" again. We actually did this lab(s) last school year. The students and I learned a lot. Without typing all the results - here are some main points that we learned - relearned.

1. Setting the flag pole has a big influence on how the flag works.
2. Proper balance of the flag is of major importance. Goes with #1
3. Heavier flags - regardless of daisy wheel or not, will go past the correct angle then have to "come back". (on the ones we tested)
4. A lot of flag design will come to personal choice in what you want that flag to do.

We (the class and I) learned a lot about experimental procedures and the difference between theory (in the classroom) and reality (actually doing it). It was an overall great project.

We are in the process of figuring out a new benchrest project for this year.

Stanley
 
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We are in the process of figuring out a new benchrest project for this year. Stanley[/QUOTE said:
How about a vane or flap or something other than tails to give a more accurate measurement of wind velocity.

Donald
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I have thought of doing something similiar to what you wrote about. I was just going to "turn them loose" and design something to measure wind speed. Individually at first - then similiar designs can partner up. Then compare their designs against Gene Begg's wind probe. That is def. an option this year. I like to get the drafting/construction students involved - we design - they make - we test - they fix, etc. Cross teaching and gets more students involved. Thanks for the interest.

Stanley
 
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