Main Discussion Area > Flight Bows
High gear/low gear
Tuomo:
--- Quote from: avcase on April 11, 2019, 01:47:29 pm ---Virtual mass is also not so constant either. If you do a lot of testing over a wide range of arrow weights, some designs will show a pretty consistent virtual mass regardless of arrow weight, others show decreasing virtual mass with progressively lighter arrows, and some designs will show the increasing virtual mass with lighter arrows.
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Could you please elaborate this? Surely there is some kind on trend? For example, it seems that high gear bows is the design, which shows decreasing virtual mass with progressively lighter arrows? What are the design features, as general?
--- Quote from: Del the cat on April 11, 2019, 12:25:30 pm ---Nope, if it is too light the drag will overpower it's momentum/kinetic energy.
I't the old ping pong ball vs golf ball thing.
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That is true but what is the real effect with real arrows? For example, what would be theoretically difference in distance with two dimensional identical arrows - 150 grain and 200 grain - if the speed is for both 200 fps? Or other way around, how much faster 150 grain arrow should be that it would fly as far as 200 grain arrow?
I think that difference is insignificant and thus the fastest arrow arrow has the most potential in flight shooting.
Selfbowman:
Toumo i agree with Alan . That's what I have seen at the flats. Light is not always faster. The first five feet and where the arrow lands is two different critters. I've shot enough to witness this. And I have only been doing this a couple years. Maybe I did not understand your post either. It don't take much for you math guys to get over my head. O:). Arvin
Del the cat:
--- Quote from: Tuomo on April 11, 2019, 10:49:03 pm ---
--- Quote from: avcase on April 11, 2019, 01:47:29 pm ---Virtual mass is also not so constant either. If you do a lot of testing over a wide range of arrow weights, some designs will show a pretty consistent virtual mass regardless of arrow weight, others show decreasing virtual mass with progressively lighter arrows, and some designs will show the increasing virtual mass with lighter arrows.
--- End quote ---
Could you please elaborate this? Surely there is some kind on trend? For example, it seems that high gear bows is the design, which shows decreasing virtual mass with progressively lighter arrows? What are the design features, as general?
--- Quote from: Del the cat on April 11, 2019, 12:25:30 pm ---Nope, if it is too light the drag will overpower it's momentum/kinetic energy.
I't the old ping pong ball vs golf ball thing.
--- End quote ---
That is true but what is the real effect with real arrows? For example, what would be theoretically difference in distance with two dimensional identical arrows - 150 grain and 200 grain - if the speed is for both 200 fps? Or other way around, how much faster 150 grain arrow should be that it would fly as far as 200 grain arrow?
I think that difference is insignificant and thus the fastest arrow arrow has the most potential in flight shooting.
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If the speed for both (dimensionally identical arrows) is the same, the heavier will fly further.... (but their speed won't be the same from the same bow).
Second question is possibly unanswerable! Prob' depends on the dimensions and properties of your "dimensionally identical arrows).
I don't think you can really separate the bow from the arrow except in thought experiments...
Del
avcase:
--- Quote from: DC on April 11, 2019, 04:00:46 pm ---Alan, with all your shooting and testing do you ever think that you're getting a handle on this stuff or is the carrot still out of reach?
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Ha! Yes-Still out of reach, but if it was easy then it wouldn’t be nearly as fun. I feel the bows are fairly straightforward. Not necessarily easy, but the physics are straightforward using the same kinds of basic physics like those used to launch a car in space. Haha!
I don’t feel very confident that I have flight arrows figured out. I just don’t have enough data points. The only good news is that I have made a lot of progress with distances this last two years, after years of almost no improvement. But I can’t say for certain why the changes I have made seem to work. I just have a lot of semi-educated guesses.
Alan
avcase:
--- Quote from: Tuomo on April 10, 2019, 09:56:41 pm ---
--- Quote from: avcase on April 10, 2019, 04:07:05 pm ---There is one major drawback as far a small flight shooting is concerned, the efficiency is relatively low and it starts to run into a wall below 8-9ggp. This is one design where the faster bow with heavy arrows is not the fastest with lighter arrows. Alan
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Why? What are the physical reasons of that?
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I can send you a link to a video, and it will pretty clearly show a tremendous amount of energy left in the limbs when the arrow leaves the string. The physical reasons have to do with the distribution of mass and stiffness in the limb. It uses a long flexible limb with many high energy vibration modes, and this allows the limb to flex and buckle rather than force its own kinetic energy through the string and into the arrow. At slower speeds, this isn’t a problem. When I say slower speeds, I mean slow by flight shooting standards, but it is an incredible performer at typical hunting arrow speeds.
Alan
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