Post by: NDTerminator on January 30, 2010, 09:59:00 AM
Enter your bow & the arrow it's tuned for's data into Stu's Calculator. Now start changing the centershot data both in & out 1/16" at a time. Viva la differences!!!
To get the correct base centershot data on my CM's, I contacted Cujo and got the word straight from the bowyer's mouth, -1/8". I then measured their centershot as I have the H2s set up using a T-300 rest with the spline point removed & replaced with a small piece of rug rest, between +1/16 & +1/8".
Absolutely astonishing have much difference in dymanic poundage there is between -2/16 and +2/16 centershot!
Post by: SlowBowinMO on January 30, 2010, 11:40:00 AM
Post by: lt-m-grow on January 30, 2010, 11:47:00 AM
Quote
Originally posted by SlowBowinMO:Put me into that category. I have been learning this "simple" traditional stuff for 5 years now and I didn't realize this until playing with Stu's calculator a month ago.
Absolutely! Shelf depth is very crucial in determining spine and is unfortunately overlooked by a lot of newer archers. In my experience the center shot is second only to actual draw weight when trying to determine the correct spine.
Post by: Tyke on January 30, 2010, 12:02:00 PM
Post by: David McLendon on January 30, 2010, 12:09:00 PM
Post by: Tyke on January 30, 2010, 12:23:00 PM
Post by: moebow on January 30, 2010, 12:30:00 PM
This can be agravating but extra hands help hold things still.
Bottom line is: half the width of the bow at the fades is the center line and a square line to the paper at the strike plate will give you the measurement. The more carefull you are the more accurate the measurement. There's probably an easier way but I don't know what it is and the above works for me and gives good results with Stu's great calculator
Post by: Bill Carlsen on January 30, 2010, 12:32:00 PM
Post by: pcappy08 on January 30, 2010, 12:37:00 PM
Post by: Tyke on January 30, 2010, 12:45:00 PM
Post by: George D. Stout on January 30, 2010, 12:54:00 PM
If there is a big fat guy, sitting in the aisle seat...and he will not move, you must be very flexible to get around him to go to the bathroom 8^). If he is a little, pencil thin fellow, you can buzz right by with little adieu. Spine!
Post by: MSwickard on January 30, 2010, 01:52:00 PM
Mike
Post by: daveycrockett on January 30, 2010, 02:55:00 PM
Quote
Originally posted by MSwickard:The +/- factor is also why so many don't get good results using the calculator IMHO.
the +/- of center shot is the main reason most cannot get good arrow flight. Stu's Calc. sure help in this dept.
Mike
Post by: wingnut on January 30, 2010, 02:59:00 PM
Make sure to adjust for thickness of strike plate.
Mike
Post by: Bruce Martin on January 30, 2010, 03:29:00 PM
Post by: Jerry Wald on January 30, 2010, 03:38:00 PM
This is my first go at these - Safari's and I just ordered so AD's to try with the new bow I am getting.
I know the ACS will be cut 3/16" past center.
Jer Bear
Post by: moebow on January 30, 2010, 05:00:00 PM
Post by: legends1 on January 30, 2010, 07:38:00 PM
I do craft my bows to center because it does give arrow choice advantages,but i would not discourage someone away from a bowyer who cuts to center.Some very good riser designs out there are best cut to center for strength.If i got long winded sorry.
Mike
Post by: Kenneth on January 30, 2010, 07:44:00 PM
Post by: swampdrummer on January 30, 2010, 09:36:00 PM
If my thinking is correct then the center shot will change with every change in arrow diameter?
I guess I'm still not real clear as to what the arrow is trying to paradox around. Wether its the point that the arrow is touching as it sits on the rest/sideplate or the riser as a whole. I relieze it has to clear the whole riser. Is the arrow trying to clear the actual spot on the side plate that it rests against? Hmmmmmmmmm
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Post by: Mudd on January 31, 2010, 12:50:00 AM
God bless,Mudd
Post by: Blackstick on January 31, 2010, 06:16:00 AM
http://www.heilakka.com/stumiller/Dynamic%20Spine%20Calculator%20Instructions%2011-22-09.pdf
Stu Miller explains how to do the measuring and has a picture example.
Post by: Bruce Martin on January 31, 2010, 07:24:00 AM
Post by: Rob DiStefano on January 31, 2010, 08:33:00 AM
key words, 'added advantage'.
makes for arrow tuning lots easier.
still, higher or lower spined arrows for a given stick bow holding weight can still be made to fly well from bow shelfs not cut to center or even cut lots before center, albeit with some understanding and some efforts. and in this case, aiming the arra and front end loading are you and yer arra's best friends.
Post by: Blackstick on January 31, 2010, 09:16:00 AM
(http://i548.photobucket.com/albums/ii322/Blackstick-photos/00small55408897.jpg)
Post by: robtattoo on January 31, 2010, 10:47:00 AM
Anyway, what I was trying to say was;
Y'all are talking about centre CUT & not centre SHOT
It may sound like petty semantics to you, but the two things are totally different. Centre SHOT would require a bow to be cut PAST centre.
Post by: George D. Stout on January 31, 2010, 01:19:00 PM
I much prefer a bow that is cut close to center, but not past. Less fiddlin' and mostly less finicky.
Post by: Jason R. Wesbrock on January 31, 2010, 03:53:00 PM
Post by: Jerry Wald on January 31, 2010, 06:17:00 PM
My bow is 3/16 past center and I will put a hair plate on it making it 1/4" past center
Then I will be trying safari's and AD which are tapered.
jer Bear
Post by: Rob DiStefano on January 31, 2010, 06:28:00 PM
Quote
Originally posted by robtattoo:GLAD you made this post, rob, as there are newbies out there who do need to understand those differences you've outlined. :thumbsup:
Hmmmmm. Won't let me edit a post. Wierd.
Anyway, what I was trying to say was;
Y'all are talking about centre CUT & not centre SHOT
It may sound like petty semantics to you, but the two things are totally different. Centre SHOT would require a bow to be cut PAST centre.
Post by: raideranch on January 31, 2010, 06:39:00 PM
If you can tune your arrows for perfect flight without understanding center shot you will be alright but if you learn the concept you could tune them more easily.
Post by: Rob DiStefano on January 31, 2010, 07:32:00 PM
assuming the limbs are well tillered and not crooked, the center of the bowstring will be directly over the centerline of the bow, as that line is drawn down the entire belly of the bow.
for a true 5/16" diameter arrow to be used and shot as TRUE centershot, the bow's riser arrow shelf plate would need to be cut 5/32" (half the diameter of the arrow) past the bow's centerline, plus at least another 1/16" to account for the arrow plate protective material (leather, velcro, teflon, etc). imo, that's plain silly and not needed. in fact, i believe most archers would have a tough time shooting such a bow.
there will always be arrow flight issues with any stick bow - if not due to how the shelf is cut, then the arrow spine and the fact that finger shooters torque the string and add arrow pressure to the arrow plate.
a stick bow's shelf that's cut and protected to allow a resting arrow's *side* to measure 1/8+" off center is just fine for all archers. and that's how the vast majority of bows are crafted today.
ymmv.
Post by: Jerry Wald on January 31, 2010, 07:40:00 PM
Is this the reason they shoot well too.
Just asking...I used to just take and arrow and tune it to the bow...took a bit of playing bu tmostly doable if you weren't concerned with tip weight and FOC.
But now that I have leraned about the FOC and EFOC I am trying to get the tip weight up to help with penetration.
I have read all the Ashby reports and followed along on most of the posts here on the subject, but when I read that Terry shoots his AD's with all different combos of tip weights I am curious to why.
Is it the make up of the tapered shaft. then I read where some ppl were having trouble getting the Alaskans and the safari's to tune in their bows.
Anyway I will be interested in your response.
thanks Jer Bear
Post by: Rob DiStefano on January 31, 2010, 08:13:00 PM
for a better insight into ad trads and tradlites, just look at the ad spine charts (http://www.badgerarrow.com/store/index.php?main_page=page&id=1&chapter=0&zenid=c38e4c065c581c8b30b8b54da243eb20) ... just look at the enormous latitude of arrow lengths and bow weights for ONE arrow spine!!! you'd never see that with an alum or woodie spine chart!!! that's enuf to have ya scratchin' yer head for a good while. :D
it's been said lotsa times before, and it's sure worth saying again - aside from using the highest holding stick bow weight you can *master*, your arrows must fly well, your broadheads must be razor sharp and you must be able to put that arra in the right spot consistently.
with the above in mind, gpp, foc and efoc are things, tools of a sort, that can possibly add to the highlighted text above. imo, terry is an excellent trad bowhunter who has hunted and killed LOTS of very worthy critters. he has an intimate understanding of what tools get the job done for him, not for me or you.
so, all the gpp, foc, efoc, lmnop, skinny strings, etc stuff needs to be put in context with what are the the main priorities of a trad bowhunter.
we are all experiments of one, and each of us needs to use the tools that work best for us.
me? i'll take the gpp and efoc and skinny string advantages any day - i need all the help i can get! :D
Post by: Jason R. Wesbrock on January 31, 2010, 08:16:00 PM
Quote
Originally posted by Jerry Wald:For finger shooting, you don't want the arrow perfectly in line with the string. Ideally, when you nock an arrow and visually line up the string with the center of the bow's limbs, the tip of the arrow should be pointing just a little to the left of the string (right-handed shooter).
So Jason - is past center more forgiving or is close to center more forgiving?
My bow is 3/16 past center and I will put a hair plate on it making it 1/4" past center
Then I will be trying safari's and AD which are tapered.
jer Bear
The further to the left your arrow points, the further from centershot the bow, and generally speaking, the less forgiving it will be.