Vibe

Boyd
I think that the real problem that has arisen about Calfee's work is entirely about his choice of words. If he had simply said, when I configure this way, I get this effect, there would have been nothing to argue about.
Well said Boyd.

I don't think you could see what's occurring on a video. But call it what you want there is an area that appears to be completely stopped with vibration on both sides. You can even clamp it with you thumb and forefinger and it will not affect the right and left vibrations. Whatever nomenclature you use, it's easy to see why Bill refers to it as the "parallel node".

Here is a post by someone looking at what Bill is trying to convey.Vibe is correct in his description but I think most highschool graduates knew what Bill was trying to convey 7 years ago.Its a shame with the internet and all the brain power here today it couldn't be explained in simple enough terms so that a simple country boy could understand it.Teaching a student to understand the math is always better than just getting the answer right in my humble opinion.

As you know my tuner posted above can be rotated many times.The problem with it's design is that I might have the weight the right distance in front of the crown but the antenna arms may be XX degrees out of phase.
My rifle needs 11-13 ounces on it for best results but that tuner body being made out of stainless takes away half of my available tuning range on the extended arms.The next hurdle is the big washers used to add the weight make your scope blurr up.
I am now going with an aluminum body fitted with a snug fitting aluminum shaft collar that has the extendable arms muonting hardware welded in place.I will then add weight until the vertical error is gone then loosen up a single setscrew and rotate the arm without advancing or retracting the weight.The shaft collar will butt up against a shoulder.Right now turning the arms 90 degrees throws the rifle out of tune.If I remove the arms turning the tuner 90 degrees also throws the rifle out of tune.
I have some very short and very long arms as well and will try a single arm with all of the required weight on it as well.
Lynn
 
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Question for Varmit Al

Is the vertical dotted line the point at which the bullet leaves the barrel?

Thanks

Bill
 
Question for Varmit Al

Is the vertical dotted line the point at which the bullet leaves the barrel?

Thanks

Bill

Yes. I forgot to add the Muzzle Exit Time to the legend. Sorry. I added it to the legend and uploaded a the new graph, but it doesn't show yet.
vibe-muzzle-mass-comparison.png

Good Hunting... from Varmint Al
coyotel.gif
 
Yes. I forgot to add the Muzzle Exit Time to the legend. Sorry. I added it to the legend and uploaded a the new graph, but it doesn't show yet.
vibe-muzzle-mass-comparison.png

Good Hunting... from Varmint Al
coyotel.gif

Howdy Varmint Al,
Would I be correct in understanding that the barrel with nothing on it would tune a broader velocity range of ammo at a longer distance, say 100 yards for the sake of argument, than the other two options, using compensation theory?

Thanks!

Greg
 
Howdy Varmint Al,
Would I be correct in understanding that the barrel with nothing on it would tune a broader velocity range of ammo at a longer distance, say 100 yards for the sake of argument, than the other two options, using compensation theory?

Thanks!

Greg

Greg,
No. Compare the time interval from the valley to the peak of the curve. For the plain barrel, the interval is about 0.0028 - 0.0024 = 0.0004 sec. For the blue curve, 0.0031 - 0.0023 = 0.0008 sec. The window is twice as long, but since the slope of the curve is less steep, the amount of compensation is less. The perfect amount of compensation depends on several factors.

To help visualize how close the different barrels are to achieving perfect compensation, an alternative way to plot this information that is useful is elevation (of the bullet strike on the target) versus muzzle velocity. Such a plot depends on external ballistics and an assumed relationship between muzzle velocity and bullet exit time, but shows perfect compensation as a horizontal line.

Cheers,
Keith
 
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