Carp
The highest point in the barrels whip occurs at a quarter wavelength and the lowest point occurs at 3/4 wavelength.
The barrel appears to be flat/straight at zero wavelength,half wavelength and full wavelength.
Waterboy
Carp
The highest point in the barrels whip occurs at a quarter wavelength and the lowest point occurs at 3/4 wavelength.
The barrel appears to be flat/straight at zero wavelength,half wavelength and full wavelength.
Waterboy
V
Vibe
Guest
See you CAN change your point of view a bit.
If it's 3" wide and 0.0002" at each end - it's still an X shape. Though if it is located at the muzzle it's more of a > shape. But it is NOT parallel. Were it truely parallel it would be of no benefit, as the shots fired after the water vapor condensed in the bore would have a different muzzle velocity and turn into a flipper. The very fact that you can get this NOT to happen is CLEAR evidence that Varmint Als animations are indeed spot on..
Vibe
If it's 3" wide and 0.0002" at each end - it's still an X shape. Though if it is located at the muzzle it's more of a > shape. But it is NOT parallel.
Was I right about looking at it with the naked eye?'
Also is there an advantage to putting the muzzle exactly at the node according to the graphics? I realise we want it on the rise but is the exact center of the node a plus?
Waterboy
If it's 3" wide and 0.0002" at each end - it's still an X shape. Though if it is located at the muzzle it's more of a > shape. But it is NOT parallel.
Was I right about looking at it with the naked eye?'
Also is there an advantage to putting the muzzle exactly at the node according to the graphics? I realise we want it on the rise but is the exact center of the node a plus?
Waterboy
V
Vibe
Guest
Yep. which still makes it wrong
According to Bill there is a difference in the results and I have no reason to doubt what he has actually SEEN. In addition to that the node will have the absolute minimum of lateral (or vertical) movement - at that point all motion is going to be angular (at least from the 2nd mode vibration) even at the "end of travel points" just before the motion reverses. Anywhere other than at the nodal POINT itself and this "stopped" location is under the maximum lateral (or vertical) acceleration. Harmonic motion is like that fastest motion happens at the points of lowest acceleration and the lowest velocities happen at the points of highest acceleration - except at the exact point of the node where all motion is agular instead of translational.
V
Vibe
Guest
Ask Bill. He's done more testing.
V
Vibe
Guest
Looks like you answered your own question. Apparently it's not.
P
pacecil
Guest
Lynn said.....
The highest point in the barrels whip occurs at a quarter wavelength and the lowest point occurs at 3/4 wavelength.
Would this be true if the wave had the shape of a parabola instead of a sine wave?
The highest point in the barrels whip occurs at a quarter wavelength and the lowest point occurs at 3/4 wavelength.
Would this be true if the wave had the shape of a parabola instead of a sine wave?
P
pacecil
Guest
Lynn said...
Was I right about looking at it with the naked eye?'
Are you talking about what you see with the naked eye when you look at a vibrating barrel?
Was I right about looking at it with the naked eye?'
Are you talking about what you see with the naked eye when you look at a vibrating barrel?
Pete Wass
Well-known member
It's quite difficult
for an old mechanic like myself to understand why most of this discussion means anything in the real world of shooting. Shooting is a results oriented sort of thing. If something works, who cares why? as long as it does. perhaps all this is like trying to quantify what makes a hummer barrel HUM, eh?
for an old mechanic like myself to understand why most of this discussion means anything in the real world of shooting. Shooting is a results oriented sort of thing. If something works, who cares why? as long as it does. perhaps all this is like trying to quantify what makes a hummer barrel HUM, eh?
P
pacecil
Guest
In the real world of mechanics does it ever help you solve a problem by knowing what's going on inside the engine?
C
Carp
Guest
Lynn,
Not picking on or at you, I'm not a mathematician nor a physicist. But I ask this question to all who think they know. Can a tuner be set to a setting that can have the muzzle pointed at the EXACT same spot from January to December in say Indiana? We see temperature differences from some -15F to 105F. Do steels that barrels are constructed of behave the same in this temp. range at the same exact time? Because the bullet of VARIOUS velocity must do that along with the hardware (barrels). I'm un-convinced that the stopped muzzle or sweet spot can be proved in any shape or form. Why, some may ask? Because I know a few great shooters that won't shoot in April and October right here in Indiana. It's not because their fingers are too cold and they can't load the rifle. Rimfire ammo is a much more viscous animal than hand loaded, controlled centerfire ammo and less consistent.
Carp
Originally Posted by Carp
It's the HALF WAVE THEORY of the stopped muzzle. The stopped muzzle is the bullet leaving the muzzle at the HIGHEST point of muzzle travel at the EXACT SAME TIME.
Carp
Carp
The highest point in the barrels whip occurs at a quarter wavelength and the lowest point occurs at 3/4 wavelength.
The barrel appears to be flat/straight at zero wavelength,half wavelength and full wavelength.
Waterboy
Not picking on or at you, I'm not a mathematician nor a physicist. But I ask this question to all who think they know. Can a tuner be set to a setting that can have the muzzle pointed at the EXACT same spot from January to December in say Indiana? We see temperature differences from some -15F to 105F. Do steels that barrels are constructed of behave the same in this temp. range at the same exact time? Because the bullet of VARIOUS velocity must do that along with the hardware (barrels). I'm un-convinced that the stopped muzzle or sweet spot can be proved in any shape or form. Why, some may ask? Because I know a few great shooters that won't shoot in April and October right here in Indiana. It's not because their fingers are too cold and they can't load the rifle. Rimfire ammo is a much more viscous animal than hand loaded, controlled centerfire ammo and less consistent.
Carp
Originally Posted by Carp
It's the HALF WAVE THEORY of the stopped muzzle. The stopped muzzle is the bullet leaving the muzzle at the HIGHEST point of muzzle travel at the EXACT SAME TIME.
Carp
Carp
The highest point in the barrels whip occurs at a quarter wavelength and the lowest point occurs at 3/4 wavelength.
The barrel appears to be flat/straight at zero wavelength,half wavelength and full wavelength.
Waterboy
Pacecil
We don't want our barrel looking like a parabola we want it looking like a extremely shallow sine wave and I stand by my statement.
On the naked eye statement I was referring Vibe to a post I did a while back.If you took 500 people and put them in a old picxk-up truck and drove them down a bumpy country road and asked them to look at the trucks antenna what would they see? They would see a standing wave.Now ask those same 500 people how they would describe the node?
My guess is alot of them would say the node is a short section that doesn't bend or it forms a parallel node.
Vibe was saying just because we see it doesn't make it so.
Waterboy
We don't want our barrel looking like a parabola we want it looking like a extremely shallow sine wave and I stand by my statement.
On the naked eye statement I was referring Vibe to a post I did a while back.If you took 500 people and put them in a old picxk-up truck and drove them down a bumpy country road and asked them to look at the trucks antenna what would they see? They would see a standing wave.Now ask those same 500 people how they would describe the node?
My guess is alot of them would say the node is a short section that doesn't bend or it forms a parallel node.
Vibe was saying just because we see it doesn't make it so.
Waterboy
S
steve b.
Guest
Excellent work Al..!
I have worked with many National Lab folks, and you have all been top notch! Well done.
I have worked with many National Lab folks, and you have all been top notch! Well done.
P
pacecil
Guest
Lynn...
When you bend a barrel by applying a moment to it, as Varmint Al does in his work it bends in the shape of a parabola.
When you bend a cantilevered barrel by adding a uniform weight along it, as happens when a barrel droops down from it's weight, it bends in the shape of a parabola.
When you bend a barrel down by adding a tuner weight to it, it bends down in the shape of a parabola.
When you hang a barrel up without the receiver and hit it with a hammer it will start vibrating in a form that depends on the shape of the hammer, where you hit it, and how hard you hit it. After a short time the hanging barrel will start to vibrate (bend) in the shape of a sine wave.
If you vibrate a antenna by wind forces and car vibration it will vibrate in the form of several parabolas.
If you vibrate a cantilevered barrel with cantilevered section at the node the curve would be made up of parabolas joined to a section through the nodes that are not bent, that is, straight. (this is the Calfee shape)
When you bend a barrel by applying a moment to it, as Varmint Al does in his work it bends in the shape of a parabola.
When you bend a cantilevered barrel by adding a uniform weight along it, as happens when a barrel droops down from it's weight, it bends in the shape of a parabola.
When you bend a barrel down by adding a tuner weight to it, it bends down in the shape of a parabola.
When you hang a barrel up without the receiver and hit it with a hammer it will start vibrating in a form that depends on the shape of the hammer, where you hit it, and how hard you hit it. After a short time the hanging barrel will start to vibrate (bend) in the shape of a sine wave.
If you vibrate a antenna by wind forces and car vibration it will vibrate in the form of several parabolas.
If you vibrate a cantilevered barrel with cantilevered section at the node the curve would be made up of parabolas joined to a section through the nodes that are not bent, that is, straight. (this is the Calfee shape)
B
B. Harvey
Guest
Sorry Carp
I must politely disagree with you. A rifle barrel is one wavelength, either 1/4, 3/4, 5/4 or 7/4. A cantilever beam is a 1/4 wave machine which means it is GOING to be one of the fore mentioned. The node in the barrel tells us the mode of vibration.
Go here an look at the second mode for a fixed-free beam.
http://paws.kettering.edu/~drussell/Demos/Flexural/bending.html
I must politely disagree with you. A rifle barrel is one wavelength, either 1/4, 3/4, 5/4 or 7/4. A cantilever beam is a 1/4 wave machine which means it is GOING to be one of the fore mentioned. The node in the barrel tells us the mode of vibration.
Go here an look at the second mode for a fixed-free beam.
http://paws.kettering.edu/~drussell/Demos/Flexural/bending.html
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B
B. Harvey
Guest
Question for Al.
On your graph, it shows a plateau on the upswing where the graph line is flat.
How is that happening?
On your graph, it shows a plateau on the upswing where the graph line is flat.
How is that happening?
P
pacecil
Guest
To a whole bunch of posters in this thread....
All of you had better learn to tell the difference between pictures that show barrel shape and pictures that show position of the muzzle verses time!
All of you had better learn to tell the difference between pictures that show barrel shape and pictures that show position of the muzzle verses time!