A plug for trad

[Mark]

I spent a couple of days on the Reds last week to get a mate some time in the bush and away from town and hopefully a chance on his first deer.

He shoots a recurve these days but recently had a spill off his dirt bike and cracked a bone in his arm. I loaned him a light recurve to build up again but he decided to take his old compound on this hunt.

While his compound rig had done the job on many a western pig hunt, deer are a differant story and I think he is still cursing it.

One lot of deer we got onto were browsing away from us so I skirted around the top (up wind) side of them hoping that they would break back towards Geof. As luck would have it they did and one hind stoped side on at about 12 yards from him.

All it took was the slight click of the snap-on type nock going onto the string to alert the deer that something was there and then the metalic tap of the arrow falling off the launcher against the "un-padded" sight window and there was nothing but a white bumflash left of his g'me opportunity.

All part of the game I guess. If the deer had stopped at 35 yards it may not have heard the offending noise and stood to have the appropriate pin put behind its sholder and there would have been more venison on the table.

It was a good experience/lesson and ephasizes again the need to set your gear up properly for the hunt.

It was a good camp, good company, good oppertunity and a good lesson, what more could you ask for?

Mark

PS. Is there a spell check option available anywhere here Erron?

[erron]

Great post Mark!

I've often wondered how some of the compound guys quieten their bows, which in some cases sure make a lot of noise

There is a spellchecker option coming in the next release. There is a non-official modification - which is hell to set up - available now. I'd rather spend time on other stuff, unless you feel it's real important. Could you cut'n'paste into Word, intead, while we wait for the NEW IMPROVED, WHITES WHITER THAN WHITE, COLOURS BRIGHTER version of the BB software? It also will include other goodies like graphic posting, so I'd rather wait for the official, easy-to-install release.

good to hear from you!

Erron

[Stickbow Hunter]

Good to hear of your great time spent out bush.

You said "It was a good camp, good company, good opportunity and a good lesson, what more could you ask for?"

You got it mate - That's what it's all about!!!

Jeff

[Mark]

Don't hurry the spell check on my account Erron. I was just wondering as spelling is definately not my strong point.

To hide my ignorance I will cut n' past from word just been to lazy I guess.

Mark

[doninkaliphornistan]

... this may not be related to this particular subject matter as posted by this thread but ...

quote: I've often wondered how some of the compound guys quieten their bows, which in some cases sure make a lot of noise.

i've found that (with c-c-c-compound or trad bows) the better the bow is "tuned" in conjunction with the CORRECT arrow, the less the effort to quieten the bow will be as the bow will not be as noisy.

i know this statement will generate much weeping, wailing and knashing of teeth but, a heavier arrow will generate less noise and vibration to dampen.

i find that with proper gripping of the bow, string thickness, follow through and arrow weight, i normally do not have to use sting dampeners or noise supressing devices.

it may not be the "fastest" arrow i can shoot from the given bow but i'm not a "speed freak". i'm more interested in shooting the heaviest shaft with the sharpest broadhead into the most vital spot.

[russ]

i have felt on the shelf/riser, rubber heatshrink tubing on the rest prongs and a tiny section of eva foam on the shelf to dampen the impact of the dropaway rest..this takes care of any noise and is well worth the effort..russ

[erron]

Interesting feedback russ, as I've wondered about this too. thanks.

a heavier arrow will generate less noise and vibration to dampen.

Don, I've found the same myself, through trial and error. Much less hand shock with the heavier shafts, too.

Erron

[Griffo]

Physics guys...physics.

The law of energy states: Energy is neither created nor destroyed, it merely changes from one form to another. (maybe not EXACTLY that, but near enough).

What does this mean with regards to a noisy bow?

Easy. When you draw you bow and bend the limbs you are storing potential energy. When you let the string go, this energy is transferred from being potential to being kinetic (ie it goes from being stored in the limbs into creating the movement of the arrow).

NOW, a LIGHTER arrow requires LESS energy to get it moving. A HEAVY arrow requires MORE energy to get moving. It's like pushing a fridge or the box it came in. The lighter one takes less effort to move.

BUT, remember, each time we draw our bow, we draw it to the same anchor point therefore storing the same amount of energy in the limbs each time.

SO, when we shoot a lighter arrow that requires LESS energy to get moving, there is MORE energy 'left over' (remember it's neither created nor destroyed) and this 'left over' energy must disapate somehow to somewhere. HOW? It becomes vibration, and what does vibration cause? Noise!

CONVERSLY, when we shoot a heavier arrow that requires MORE energy to get moving, there is LESS energy 'left over' and thus less vibration and less noise.

Compound shooters use 'vibration absorption devices' such as rubber limbsavers and string whiskers and stabilizers etc to absorb this extra energy in the 'vibration' stage thus preventing it from getting to the 'noise' stage. This means a quieter bow allowing you to shoot lighter arrows (let's not get into that argument) and avoid animals jumping the string.

For example (and some of you won't believe me but others of you have seen it for yourselves), I have a york timber compound set at 50pounds. I shoot 2117 allows with 4 inch fletching and 130grn points. It only a 'bees dick' louder than any recurve. Why? Not limbsavers, not a stabilizer but 'lighter' poundage with heavier arrows. Simple.

Hope this helps some.

Griffo

[erron]

Thanks Griffo, interesting. So, if we had no energy left over it would be because we were using an arrow so heavy it wouldn't move, right?



thanks,

Erron

[Griffo]

mmmm...dunno about that mate...

If there's no energy left over, it just means that the potential energy in the limbs has all been used up just to get the arrow moving. This would require a very heavy arrow...indeed a ridiculously heavy arrow.

To have an arrow so heavy that your bow couldn't move it? I doubt it would A: stay on the string and B: stay on the rest. So I don't think you have to worry about that Erron.

Griffo

[snakeeater]

Griffo has most of the answer, but not all of it. The missing part is what Erron asked about. When you pull your bow back, regardless of the arrow weight (mass) you are storing energy (the first point that Griffo made). When you release the string the energy transfers from the limbs to the string to the arrow which then flies towards the target. The arrow absorbs as much energy as its mass will allow in the form of kinetic energy and momentum, some of the energy is used to defeat inertia and get the arrow moving (the second point that Griffo made), and anything that is left over stays in the string and limbs and turns into vibration which we experience as handshock and noise.

So, the third part of the answer is that the heavier arrows, the ones with more mass, can absorb more of the energy that comes from the bow than the lighter arrows (with less mass). It is a basic principle of physics that an object with more mass lcan store more energy and also ooses its stored energy at a slower rate than an object with less mass. That is why a heavier arrow has more momentum (hitting power) left at the same distance down range than an arrow with less mass. It is also why a heavier arrow will make for a quieter bow since it will absorb more energy and leave less to turn into handshock and noise.

If you want a practical demonstration, take a light arrow and a heavy arrow and shoot them both at a sheet of plywood set up at 20 or 30 yards and listen to the difference in the sound they make when they hit. The heavier arrow will hit with more authority than the lighter one will.

P.S. - it helps when your next door neighbor has a Doctorate in Physics and doesn't mind explaining stuff to his seemingly brain dead neighbor.

Snakeeater

[snakeeater]

Erron, to answer you specific question, if you had no energy left over it would be because the total energy stored in the bow was equal to (what it took to move the limbs and string) + (how much energy the arrow could absorb) + (how much it took to defeat the inertia of the arrow).

Snakeeater

[erron]

More great info, thanks Snakeeater! Not sure I understand your last post, but will chew on it...

To have an arrow so heavy that your bow couldn't move it? I doubt it would A: stay on the string and B: stay on the rest. So I don't think you have to worry about that Erron

- yeah, dumb question, really, but interesting answers, just the same!

cheers,

Erron

[Griffo]

Well, admittedly I have no PhD but I did gain distinctions in my physics subjects at Uni .

Knowing what little I apparently do in the shadow of one aforementioned next door neighbour, I will still say that I don't know if I agree with the following point:

It is a basic principle of physics that an object with more mass can store more energy and also ooses its stored energy at a slower rate than an object with less mass.

A heavy arrow absorbs more energy because it takes more of the potential energy in the limbs to get it moving. It is heavier and therefore it's inertia at rest is higher. Thus, it takes a larger force to over come it, and so, it uses up more of the potential energy to get it moving. I thought I clearly said this...
Griffo Wrote

we shoot a heavier arrow that requires MORE energy to get moving, there is LESS energy 'left over' and thus less vibration and less noise.

and in saying this I explained the following...

it is also why a heavier arrow will make for a quieter bow since it will absorb more energy and leave less to turn into handshock and noise.

This notion of "oozing" energy has me baffled...a heavy arrow has more energy when it gets to the target because it has more mass and therefore higher momentum so it slows down proportionately less than a lighter arrow. It doesn't mysteriously 'ooze' energy at a slower rate.

If you want a practical demonstration, take a light arrow and a heavy arrow and shoot them both at a sheet of plywood set up at 20 or 30 yards and listen to the difference in the sound they make when they hit. The heavier arrow will hit with more authority than the lighter one will.

All this proves is that a heavy arrow (usually thicker) will vibrate/resonate upon impact at a different frequency than a lighter arrow (usually thinner) thus you hear a different noise when it hits the target. To clearly see the difference you must look at penetration. This is where we see momentum and intertia most clearly at work.

I also am in a quandry when I read the following equation:

if you had no energy left over it would be because the total energy stored in the bow was equal to (what it took to move the limbs and string) + (how much energy the arrow could absorb) + (how much it took to defeat the inertia of the arrow).

The only energy that a moving arrow possess is kinetic that has come from potential energy stored in the limbs of the bow. I am struggling to understand the concept of this 'energy that the arrow can absorb'. ]Maybe: "how much it took to defeat the inertia of the arrow at rest + the relevant change in the arrows' momentum + the energy it took to move the limbs and string", explains it more correctly.

I don't mean to be narky Snakeeater but I thought I covered all of the points you 'recovered' and that my explanations and my demonstration of my understandings of the princicpals of physics surrounding the concept in question were rather sound.

Griffo

[Guest]

Managed to put the last chapter to the story that started this thread and thought I should relate it.

I have taken Geof out for a couple more hunts since that first one. Both with deer sightings but not much stalking opportunity Then I took him out again about 2 – 3 weeks ago and all the planets aligned for him.

I should mention that Geof is 62 and also a diabetic whose job, (owner/operator of a back-hoe) does not do much to keep him physically fit.

We split up this morning just on daylight and I pointed Geof through an area that would be comparatively easy going compared to where I was headed. And give a reasonable chance or a sighting.

When I drove up to the prearranged pickup point on my way out , Goef was there wearing a grin you would be battling to drive around! His compound gear was right for the job that day (with a few modifications brought on by lessons learned).

He had put what he reckoned was a good arrow through a spiker and noted it struggling when he last saw it.. He didn’t follow far as he thought he’d give it time and meat up with me and get my help on the trail.

To shorten a long story I found his stag only about 45 paces from the hit and packed it back to the 4X4 for him.

Getting the job right on deer is still a thrill for me as I already had another one in the 4X4 from my morning but it is a greater thrill to be able to help someone else get there first .

Two bow shot deer hanging in the farmers walk in cold room, aging for the table (one a first).
It doesn’t come much better than that!

Mark K.

[erron]

Well done Mark, and well done Geoff! I can almost taste that venison as it ages!



Erron

[snakeeater]

Griffo,

You are not being snarky, and you are right in saying that I recovered what you had said, I just wanted to show the whole scenario instead of trying to interject my piece. Basically, all I was adding was that some of the energy in the system gets absorbed by the arrow, or I guess more correctly stated it gets stored in the arrow as the energy of its momemtum.

That energy doesn't just get used to defeat inertia and make noise. Like you said, hitting with authority downrange is due to the momentum in the arrow, which I believe is a way of describing how much energy is in the arrow at any given point in its flight.

My point to Erron was that when you pull back the limbs on the bow you store X amount of energy and we call that potential energy. When you release the string that potential energy turns into kinetic energy, like you said. The total energy in the system, X, gets "used up" in the form of the energy used to defeat the arrows inertia (A) + the energy to move the limbs (B) + the energy absorbed by the arrow (C) + the energy left over which turns into noise (D). You just left out the energy stored by the arrow.

We kind of said the same thing, but from a different perspective. Also, I didn't mean to type that the arrow ooses energy, I meant to type that it looses energy as it goes down range.

The basic points I was trying to make were that denser things absorb more energy then less dense things, that the arrow absorbs some of the energy from the system, and that the greater energy required to defeat inertia was not the only thing that helpded to reduce the amount of energy left in the system to become noise.

Snakeeater

[Buford]

hey cletus,
these here educated folk and usin' their legal mamby ja-hamby to try n' make us lookin' like a couple o' slack jawed yokels!

i got n' idea..... how bout ya'll explain it like this:-

big, heavy arra = penetratin' that hide and "Brandine! grab that jug o' shine and bring the young-uns, cause we eatin' tonite!"

small, light arra = "Hey Clem, ya'll be ready wif that scatter gun, cause i thin' this nittin' needle is just gonna **** em' off"



Cheers
Buford

[erron]

Buford,

I think I understand the other posts better!

Thanks Snakeeater, I see your point.

Erron

[Griffo]

No probs Snakeeater,

I must say, "looses" casts a whole different picture to "oozes".

Thanks for the clarifications.

Griffo