Primitive Archer
Main Discussion Area => Arrows => Topic started by: Sidewinder on April 02, 2008, 08:14:16 pm
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I read this once before but would like some re-clarification. Correct me where I am wrong.
Normal arrow spine will be between 5-10# below bow weight at draw length. So if I shoot a 57# bow I need to order shafts that are 45-50#.
When I shoot the bare shaft from 10-15ft , as a right handed shooter if it hits with the tail to the left the spine is too light?
1" off length of shaft stiffens the shaft approx. 5#
Most arrows are spined at 28" so if I have a 40#@28" shaft and cut it down to 26" it should now be a 50# shaft?
Where I am at now is I have a 40# shaft left over from another batch of POC that I am currently at 26" and it still appears to be hitting tail left and the tail is high.
Feedback and suggestions please....Danny
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most important thing to remember with bareshaft tuning is a clean loose. if you dont have a clean loose bareshafting is useless.
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So what you are saying is no plucking?
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Not all 57# bows are created equal. If you have a high performance 57# bow then you will need stiffer shafts.
Missing information:
What speed does the 57# bow shoot a 570 grain arrow?
Do you have a spine tester? Have you re-spined the arrow you cut down to 26"? Maybe it didn't gain 10# of spine after cutting.
Everything else in your data looks good.
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The shaft won't gain any weight, or spine, by cutting it. The difference is in the dynamic spine, which is how it acts on the bow. Theoretically, you are correct, that by cutting the shaft shorter you are stiffening the dynamic spine, but it won't show up on the spine tester. It's the same stick, after all.
What's your point weight? Where does the arrow impact the target? Where is your nock point? If it's too low, the arrow could be "bumping" the shelf on its way by, screwing up all your careful testing.
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Scattershot hit it all over the place I think. I do not pay attention to the whether or not the nock is this way or that way etc. I only worry about point of impact. Seems I read that somewhere or someone posted that once but I remember them saying that the point of impact is the important part as the fletching will correct minor deviations
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Sticknstring.....I think Sidewinder is shooting bare shafts? There is no fletching to correct minor deviations....(I hope I'm reading you right).
Hmmmm...I'm still pondering the idea that cutting a shaft does not increase spine....(don't know about that one...hmmmm....maybe it's true with non-wooden, parallel shafts? ::)).
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Point weight is 125g. I will have to weigh the arrow to see what it weighs. I am not sure what you mean when you say where is it hitting th target? Do you mean is it hitting high or low and right or left? if so then it is hitting high left. As far as nocking point where should I measure from to give you an answer?
It is a pyramid type bow. Hickory. I shot an arrow at gander mtn and it averaged 158-161fps. I do not remember the arrow weight but I can see how that might make a difference.
Jackcrafty I do not have a spine tester...yet. I can see I need one though. These were spinned by Mike at the nocking point before he sent them to me. It is a 401 grain arrow at 28" and a 125g tip. I can remeasure the arrow weight. I do have a pocket arrow weight gauge.
Danny
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Holy wuh eh yer making my head hurt, get a arrow that shoots good than make some more that match ;) pretty simple eh :D
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Sidewinder, the arrow you shot (at Gander Mtn) was probably 500 grains...that means that your bow is shooting at (or above) average for a 57# bow. Average performance would be 157fps with a 570 grain arrow @28" draw with a 57# bow. Since your draw is 26", and you're still getting 157+fps...your bow is most likely too "good" for that arrow you're shooting.
Get a stiffer arrow. ;D
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Lol Dana. Yeah I know. I'm not trying to make it too complicated it's just that I want to get some sitka spruce shafts and want to make sure before I spend my money that I get the right range of shafts for my bow.
So it seems to me that what jack is saying is that my 57# requires a stiffer arra and so then given the 5-10# spread of spine differencial some bows have from one to the next, I should probabely get 50-55"s and cut em a little long or add head weight if I need to lighten them up.
Come to think of it, I 'll bet cane shafts would be even better if I knew they were spined right. Who knows a good source for some cane shafts and what do they cost?
Danny
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arrows impacting left = too stiff
arrows impacting right = too weak
arrows impacting high = low nocking point
arrows impacting low = high nocking point
nocking point will change porpoising, spine will change fishtailing.
heavier heads weakens spine, shortening arrows stiffens spine. most arrows are spined on 26" centers. arrow spine will also be affected by center shot. true center shot bows (like most recurves) are less fussy about arrow spine. if you're shooting a bow without center shot (like most longbows), go with a slightly weaker spine, so the arrow has a chance to "bend around the handle" in paradox. also, type of string makes a slight difference. FF strings need slightly stiffer shafts.
the bottom line? you have to experiment, until you find what each bow likes.
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Jackcrafty I know he was talking about bare shafts. All I was trying to get across is that nock end relative to point end is really not a good indicator of arrow tuning. I guess i was not clear on that. Even target material can sling the nock end this way or that. Point of impact (like adb says and sidewinder alluded to) is the important thing.
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Hi,
here's a link to a spine calculator from a german website which I find quite useful to determine the approx. spine.
The calculator itself can be set to english.:
http://www.bogenblog.de/index.php?/pages/spine-rechner.html (http://www.bogenblog.de/index.php?/pages/spine-rechner.html)
Radon
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have you seen this one yet? I like it.
http:// www.bowmaker.net/index2. htm
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That is a bad link....perhaps you did not copy it correctly?
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No actually I disabled it no links are allowed to non paying advertisers, sorry about that but doin my job here.
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No apologies needed Dana. Your top notch work as a moderator is one of the reasons I call this site home and continue to come here several times a day. I absolutely love my PA brothers...
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Thats good to hear, the goal is to continue to be the best.
You can always PM him for the link ya know ;)
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have you seen this one yet? I like it.
http:// www.bowmaker.net/index2. htm
It dont work????
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nope like I said I disabled it, but yer a smart guy I'msure you can figure a way around it :)
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YEP
>:D
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I'm not THAT curious.... ;D
Back to my many projects!!!!
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whoops. sorry about that. Didnt mean to break any rules. I have no affiliation with the guy. Just thought his bow/arrow tune was pretty good and understandable.
Will watch what I link in the future.
N2
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A link to a website that isn't selling anything is fine but out of consideration for the paying
advertisers links are not allowed to non-advertisers.