Peakoverload
Member
I've recently bought myself an American Flatbow, a Buck Trail Black Hawk and when I bought it the guy in the shop measured me for some arrows which are okay but I'd like to have a go at making my own and getting a more accurate match to my bow.
I've just come across the Stu Miller Dynamic Spine calculator and this is raising a few questions.
My bow is rated at 35lb (I presume at 28" although it doesn't say). The arrows it was suggested I buy, after my draw was measured, measure 30" from the throat of the nock to the end of the shaft/base of the point, the point adds almost another inch to the arrow. Using a draw length measuring arrow, when I'm at full draw it's at 28.5" at the back of the shelf (which is also the deepest part of the grip) and measuring to the very front of the bow it's exactly 30".
If I add these into the calculator (Bow weight 35lb, rated draw length 28", my draw length 28.5 and center cut 1/8th) it suggests that the dynamic spine I need is 34.7lb.
However, when I use a bow scale to measure the actual draw weight of my bow at my draw length, it's measuring 44lb. If I set that as the bow weight it says that the dynamic spine I need is 44.1lb. That's one hell of a difference!
What is then more confusing is that on all the charts I've seen for wooden arrows, it says that for a Flatbow with a 28" draw with a draw weight of 35lb I would need arrows of 40/45lb but if the draw weight is 44lb then I need arrows of 45/50lb. If you said my draw was 29" then it's 45/50 or 50/55lb respectively.
Coming from a recurve background, a difference in spine calculations of 9.5-20lb is making alarm bells ring. Anyone know which figures I should trust?
I've just come across the Stu Miller Dynamic Spine calculator and this is raising a few questions.
My bow is rated at 35lb (I presume at 28" although it doesn't say). The arrows it was suggested I buy, after my draw was measured, measure 30" from the throat of the nock to the end of the shaft/base of the point, the point adds almost another inch to the arrow. Using a draw length measuring arrow, when I'm at full draw it's at 28.5" at the back of the shelf (which is also the deepest part of the grip) and measuring to the very front of the bow it's exactly 30".
If I add these into the calculator (Bow weight 35lb, rated draw length 28", my draw length 28.5 and center cut 1/8th) it suggests that the dynamic spine I need is 34.7lb.
However, when I use a bow scale to measure the actual draw weight of my bow at my draw length, it's measuring 44lb. If I set that as the bow weight it says that the dynamic spine I need is 44.1lb. That's one hell of a difference!
What is then more confusing is that on all the charts I've seen for wooden arrows, it says that for a Flatbow with a 28" draw with a draw weight of 35lb I would need arrows of 40/45lb but if the draw weight is 44lb then I need arrows of 45/50lb. If you said my draw was 29" then it's 45/50 or 50/55lb respectively.
Coming from a recurve background, a difference in spine calculations of 9.5-20lb is making alarm bells ring. Anyone know which figures I should trust?