Mike,
I think this needs some explanation, because it is at odds with the conventional terminology of vibration analysis. First, amplitude means the peak-to-peak displacement or angle change of the vibration wave. For a given frequency, greater amplitude means that speed must increase. (Like moving point B farther from point A, to get from A to B in the same time, we have to go faster.)
Second, there is no dwell time for a muzzle. It is in constant motion. In fact, we want it to move. If we could get it to "stop," then it would not be tuned because there would be no positive compensation. What we want to happen is that the muzzle angle is rising at the perfect speed (not too fast and not too slow) such that slow bullets, which leave the muzzle later, are launched at a higher trajectory such that they hit the target at the same point as the fast ones.
Lastly, a node is normally defined as a point along a vibration waveform that doesn't oscillate in position. For a steady wave, the locations of the nodes don't change. Halfway between the nodes are the antinodes, where maximum displacement occurs.
Seems like you may be using these terms differently.
Cheers,
Keith
Hi Keith! I look forward to seeing you at a match soon.
First, technically you're correct, as usual. I was trying to keep things as simple as possible. The majority of us get confused when we start talking about amplitude and frequency. When all is said and done, how tuners work is far less important to most of us than how we can make them work for us.
For what I consider the purposes of this conversation, I think thie following definition of amplitude will suffice.
...
the maximum extent of a vibration or oscillation, measured from the position of equilibrium.
This implies a couple of things. First of all, while the muzzle technically never stops moving, it does have a maximum amount of displacement, both vertically and horizontally. The mass(tuner) at the end of the barrel, along with gravity make it's movement vertically biased. A heavier tuner does this moreso than a lighter one...again, gravity here. In layman's terms, amplitude can be considered how far the muzzle moves, in this context, vertically. But due to the fact that it oscillates, I think somewhat skinny eggshaped would be a decent description of the muzzle displacement as it oscillates, vertically biased.
When I used the term dwell time, I do so because we have a point at top and bottom where the muzzle slows and changes direction. This is where I hope bullet exit occurs, not while the barrel is at full song going in either the up or downward(biased) part of its swing. IOW, we have a point at top and bottom of LESS movement for a period. This is what I referred to as dwell time, be it technically correct or not. The area just before maximum vertical displacement is the area that I try to tune to...for positive compensation and because of it being near the top of it's oscillation, where movement is slowed before it changes direction, and starts back down.
Adjusting the tuner changes the frequency of the vibration. Again, I think this definition of frequency applies here.
...the number of cycles or completed alternations per unit time of a wave or oscillation. Symbol: F;
IOW, how far between nodes.
FWIW, I have had someone you may know at the University of Cincinnati do some viration analysis testing with my tuners. His name is Sam Glover. I hope we can conclude the testing soon. I don't think anyone fully understands everything that's going on with tuners yet, but Sam is very qualified and his son is working with him on this. He's a mechanical engineer, specializing in vibration analysis. Sam is a shooter, so he has a good understanding of what we're looking for. He's also a nuclear physicist and former adviser at Los Alamos National Laboratory.
One thing that has been proven is a 35% lowering of the frequency of the test barrel with my tuner vs, no tuner. What this tells us is that we have greater amplitude, as mentioned earlier, and a lower frequency of vibration. So, we have slowed the muzzle displacement by lowering the frequency and lengthened the period where the barrel is moving slowest in its oscillation with more amplitude. We have yet to discuss how the dampening agent in my tuners affects this, too.
Here's a good read of my basis for using particle dampening, in a research done at Texas A&M. I very highly recommend everyone read it. It's quite interesting and is why I feel like my tuners are the next step in tuner design.
http://repository.tamu.edu/bitstream/handle/1969.1/1459/etd-tamu-2003C-AERO-Marhadi-1.pdf?sequence=1
You are also correct in pointing out my misuse of the term "node". Keep in mind, I was trying to relay what I'm saying in terms that "most" of us understand...myself included.
I certainly understand you pointing out what you have, Keith. But part of the trouble with tuners is the confusion and speaking over most of our heads when it comes to describing what they do. I read your posts with interest, as I have everything I could find on the subject since 2006 or 2007, when I started playing with tuners. I'm 100% convinced that I won't be shooting without a tuner until something better comes along.--Mike