NikoTheBowHunter
Well-Known Member
Have you tired FOBs? https://fobarchery.com/ Ive been using them for the past 3 years and love em.
I havent shot them but I want to like them. In theory they are awesome. I can't get past replacing them all the time tho. I know ease of replacement is a selling point but not something want to mess with.Have you tired FOBs? https://fobarchery.com/ Ive been using them for the past 3 years and love em.
This is showing benefits to point weight for flight stability.....pushing into the wall is showing benefits to point weight at impact and negatives to nock end weight at impact and also shows how increasing general overall arrow weight isn't really doing anything....weight the pointy endFor all you straw shooters. No sand in said straws though
Sent from up in a tree
Agreed. And it was a cool video with straws!This is showing benefits to point weight for flight stability.....pushing into the wall is showing benefits to point weight at impact and negatives to nock end weight at impact and also shows how increasing general overall arrow weight isn't really doing anything....weight the pointy end
Good video to demonstrate the importance of FOC. Going somewhat back in the thread, the OP is shooting a 29" 340 shaft out of a 68# bow. We have unknowns of bow make, draw length and current total front weight and total arrow weight unless I missed those in the thread. Unless his draw length is greater than 29" he could reduce the shaft length by up to a couple of inches depending on rest. Cut below 28" and you are now changing the actual spine of the shaft, deflection is now going to be less than .340. This opens the door to increasing the front weight without as much fear of being underspined because the label on the shaft says 340. So switching to small feathers rather than vanes may be an option without messing up arrow flight. If on the other hand the arrow needs to remain at 29" the amount weight that can be added to the front of the shaft without tuning issues is limited. If the current arrow has vanes the additional weight limit at the front could be further limited by switching to feathers or it could be slightly increased by adding a small amount of additional weight at the rear from say a wrap or a lighted nock, which would increase the dynamic spine of the arrow. The primary point is Dr. Ashby's work is centered around optimal penetration without regard to system tuning. Building out the system requires considering all the factors affecting arrow flight as well as penetration objectives and a primary driver will always be the arrow shaft selected to build around. While the things Kurt and I were pointing out may not be optimal for penetration, they are the proven methods for potentially keeping an arrow in tune when the arrow spine or deflection was not quite stiff enough to support the desired changes to FOC.Here's a link to Ashby at the P&Y meeting. He demonstrates several of the things being discussed in this thread. It's less than 17 minutes long and well worth watching.
Wait, what? You can change static spine (deflection) by cutting an arrow shorter?Cut below 28" and you are now changing the actual spine of the shaft, deflection is now going to be less than .340.
I disagree. His top 3 of the 12 points to increasing lethality. The primary point is Dr. Ashby's work is centered around optimal penetration without regard to system tuning.
I don't know the difference between static and dynamic spine, but yes, shorter arrow = stiffer arrow. And as little as a quarter inch can make the difference between perfectly tuned and too stiff or too week. My 300sp and 340sp arrows are cut at different lengths (with different tip weights) to achieve the same goal of perfect flight.Wait, what? You can change static spine (deflection) by cutting an arrow shorter?
Not throwing stones. Literally just trying to understand this.
If you cut a shaft shorter than 28" you effective change the actual spine of the shaft. A 340 shaft has a deflection of .340 on 28" center. If you cut that shaft shorter that 28" it will have less deflection at center.Wait, what? You can change static spine (deflection) by cutting an arrow shorter?
Not throwing stones. Literally just trying to understand this.
Was referring to the video and my recollection of the emphasis of his writings that I read a bunch of years ago. I agree with that top 3 in that order.I disagree. His top 3 of the 12 points to increasing lethality
#1 structural integrity
#2 perfect arrow flight
#3 foc
Very interesting! I was always under the impression that the static spine was constant no matter the length of the shaft.If you cut a shaft shorter than 28" you effective change the actual spine of the shaft. A 340 shaft has a deflection of .340 on 28" center. If you cut that shaft shorter that 28" it will have less deflection at center.
No what I am saying is if you put those 2 shafts both labeled 350's on a spine tester, they should both deflect .350 or real dang close even though they are different lengths. What matters is they are both longer than 28". Cut them shorter than 28" and the deflection will decrease. For example if you cut that 350 shaft to say 27" the deflection may be more in the neighborhood of .300.Very interesting! I was always under the impression that the static spine was constant no matter the length of the shaft.
The reason I'm drilling down on this is because I just purchased the remaining Mossy Oak .350 arrows from my local Wallyworld (couldn't resist as they were $2ea). I bought some at 29in and some at 31in. They all had the exact same labelling except for the length (29" and 31" respectively). Are we saying that a given manufacturer has a different building process when constructing the same arrow at different lengths?
Am running an Easton axis 340 as well with a 75 grain brass insert and 100 grain g5 strickers, with the 2.5 inch heat vanes. They seem to shoot like practice points up to 40yrds haven't shot a whole lot past that as far FOC there like 16.5%. You may have a hard time destroying them there a pretty tuff arrow in my opinion.Looking for something to do in the off season so time to refletch some arrows. Thought about switching to heavy arrows but I have 2 dozen Axis 340s that I need to destroy first. I've used slick trick mag 125s for a few years and they've been phenomenal on critters. Right now I'm steering them with blazers but want to try something new. I do notice s little deviation from field point accuracy at longer ranges (40-60 years) even with a paper tuned setup. It hasn't been enough to be concerned with, but enough that I'd like to tighten it up. Gonna try some bare shaft tuning when it warms up for S&Gs.
Since I couldn't find much for recent comparison testing on vanes, I was wondering what others are using to steer fixed blade heads. Toying with trying heat vanes, probably in a 4 fletch. Any others try this combo with good results?
Hilarious... I've been wanting to test with a .300 for awhile now to see if I can eek out any more precision from my system but I can't bring myself to purchase more arrows. Well, last night I just cut four of those 31in .350s down to 27.5in. Praise God, He delivered!No what I am saying is if you put those 2 shafts both labeled 350's on a spine tester, they should both deflect .350 or real dang close even though they are different lengths. What matters is they are both longer than 28". Cut them shorter than 28" and the deflection will decrease. For example if you cut that 350 shaft to say 27" the deflection may be more in the neighborhood of .300.
To measure spine you would place an arrow on pegs or supports 28" apart. Either force is applied to the shaft or a weight is hung from the shaft at the center of the 28" span. The weight is just a frog hair under 2#. Then the amount of deflection is measured and that is your spine rating for that shaft. Cutting the shaft to a length less than 28 is going to make that shaft stiffer than its measured deflection. Not saying your 350 cut to 27.5 will turn out to be 300 but it will be less deflection than 350. Thats why understanding spine and dynamic spine is important when building out a system.Hilarious... I've been wanting to test with a .300 for awhile now to see if I can eek out any more precision from my system (very well tuned with the 29in shafts out to 30yds) but I can't bring myself to purchase more arrows. Well, last night I just cut four of those 31in .350s down to 27.5in. Praise God, He delivered!
For my edification, spine is measured by using a spine tester with a 28" shaft? Sorry. I'm not trying to be dense, just trying to understand what my actions (in this case, cutting an arrow below 28") are actually doing to the spine.
Boom. Schooled! Thank you!To measure spine you would place an arrow on pegs or supports 28" apart. Either force is applied to the shaft or a weight is hung from the shaft at the center of the 28" span. The weight is just a frog hair under 2#. Then the amount of deflection is measured and that is your spine rating for that shaft. Cutting the shaft to a length less than 28 is going to make that shaft stiffer than its measured deflection. Not saying your 350 cut to 27.5 will turn out to be 300 but it will be less deflection than 350. Thats why understanding spine and dynamic spine is important when building out a system.
Yes you can. Static spine is taken from the deflection of a shaft supported on both ends at 28". Cut that shaft shorter than 28" and that shaft will be stiffer.As you move the supports closer together the same weight will bend the shaft less. The lower the deflection number the stiffer the static spine.Wait, what? You can change static spine (deflection) by cutting an arrow shorter?
Not throwing stones. Literally just trying to understand this.
DUDE! Had another cup of coffee and thought about this again. This is why I was having so much trouble tuning my bow!To measure spine you would place an arrow on pegs or supports 28" apart. Either force is applied to the shaft or a weight is hung from the shaft at the center of the 28" span. The weight is just a frog hair under 2#. Then the amount of deflection is measured and that is your spine rating for that shaft. Cutting the shaft to a length less than 28 is going to make that shaft stiffer than its measured deflection. Not saying your 350 cut to 27.5 will turn out to be 300 but it will be less deflection than 350. Thats why understanding spine and dynamic spine is important when building out a system.