Primitive Archer

Main Discussion Area => Bows => Topic started by: Selfbowman on October 01, 2024, 08:31:44 am

Title: Spineing a flight arrow
Post by: Selfbowman on October 01, 2024, 08:31:44 am
Can an arrow be spined in such a way to give you more clearance at the fletchings? Also where do you hang a 2# weight on a barrel tapered arrow? At balance point?
Title: Re: Spinning a flight arrow
Post by: Jim Davis on October 01, 2024, 11:40:59 am
Hey Arvin, I've never been into flight shooting, but I can see there are a lot of things that could slightly change the outcome.

It seems to me that stiffness can have opposite effects at the extremes. The sooner the arrow quits flexing the less drag, but the stiffer the shaft, the more friction there will be at the arrow pass. There is probably a sweet spot somewhere in the spine range.

The same kind of balance is at work in the feather size/shape question.

Have fun testing. 8-)
Title: Re: Spineing a flight arrow
Post by: willie on October 02, 2024, 12:51:30 am
Can an arrow be spined in such a way to give you more clearance at the fletchings? Also where do you hang a 2# weight on a barrel tapered arrow? At balance point?


I taper atlatl darts only on the rear 1/3 and see the aft end wiggle in flight while the dart as a whole flexes less. dunno if there is something worth experimenting with there for arrows.
if I had a barrel taperd arrow that flew well, I would mesuure the spine/deflection at multiple places for future reference.
Title: Re: Spineing a flight arrow
Post by: Eric Krewson on October 05, 2024, 11:03:48 am
My Adams spine tester has 26" centers, the weight goes in the center. I don't take the deflection my tester shows as being exact but as a baseline starting point for arrow tuning.

I don't know squat about flight arrows but it seems like an arrow that comes out of paradox quickly would be the most efficient rather than one that bends this way or that for a purpose.

I paper tune my arrows to get a bullet hole with 3 feather cuts at 6ft. If I had a chronograph and checked I would suspect this would be the fastest arrow out of my bow but don't have the data to back up this theory.   
Title: Re: Spineing a flight arrow
Post by: Selfbowman on October 05, 2024, 02:26:26 pm
Eric I have the same Adams tester. I also have one that hangs on the wall. My question is where to hang the weight when the arrow is tapered so the balance point is toward the nock not the point. I’m thinking that the balance point might be the spot to hang the weight.
Title: Re: Spineing a flight arrow
Post by: Del the cat on October 05, 2024, 03:17:48 pm
Eric I have the same Adams tester. I also have one that hangs on the wall. My question is where to hang the weight when the arrow is tapered so the balance point is toward the nock not the point. I’m thinking that the balance point might be the spot to hang the weight.
I'd think the weight should be as close as possible top the point where the deflection is being measured (or sensed).
Have you tried it at different positions for comparison?
Del
Title: Re: Spineing a flight arrow
Post by: Selfbowman on October 05, 2024, 03:49:02 pm
Here ya go Del.
Title: Re: Spineing a flight arrow
Post by: Selfbowman on October 05, 2024, 03:54:50 pm
This is the balance point at the bottom of the spine scale.
Title: Re: Spineing a flight arrow
Post by: Selfbowman on October 05, 2024, 04:00:26 pm
At balance point it spined 36- .720
Title: Re: Spineing a flight arrow
Post by: Selfbowman on October 05, 2024, 04:06:46 pm
That particular arrow was balanced at center of arrow.
Title: Re: Spineing a flight arrow
Post by: Selfbowman on October 05, 2024, 04:19:55 pm
On the ace spine tester it seams to spine best when the balance point is over the resting point in the middle. So does that mean put balance point at center resting point for correct spine?
Title: Re: Spineing a flight arrow
Post by: Del the cat on October 05, 2024, 06:47:53 pm
On the ace spine tester it seams to spine best when the balance point is over the resting point in the middle. So does that mean put balance point at center resting point for correct spine?
Ah, just looked at a picture of the ace spine tester and the weight is automatically at the measurement point.
I'd say put he thickest point of the shaft at that point.... but I s'pose the important thing is to always do it the same...
But then, is that right? 'Cos if you have two arrows, one with the thickest point 1/3 from the front and the other 1/3 from the back. They would read the same spine but perform differently!
I tend to put my arrow on my rig with one support about 1" in from the nock, because I believe the stiffness is needed at the aft end of the arrow (I may be wrong tho'  ::))
Del
Title: Re: Spineing a flight arrow
Post by: Eric Krewson on October 06, 2024, 10:11:47 am
I once made a number of barrel tapered shafts, I started to 80#-100# poplar dowels from Lowe's, barrel tapered them and matched the spine by sanding the thick part, I made them all matched 55-60#. I spine tested them on my tester and found the barrel tapered shafts shot the best at the same spine as my best shooting parallel shafts. I put the weight at the same point as I always did om my tester, right next to the swing arm under the arrow.

My point is it doesn't matter where the weight is, bare shaft test your arows after you test them and found out what spine out of the tester you use shoots true.  As long as you use the same tester and weigh position your arrows will all be fine. You may spine the arows on a different tester and get different reading, that is why I use my testers reading as a baseline for all my arrows.   
Title: Re: Spineing a flight arrow
Post by: willie on October 06, 2024, 04:17:24 pm
But then, is that right? 'Cos if you have two arrows, one with the thickest point 1/3 from the front and the other 1/3 from the back. They would read the same spine but perform differently!

Del, Have you tried building arrows both ways? Moving the thickest part foreward was what worked for me with the atlatl darts I make. the idea being moving the stiffest point foreward helped settle the paradox, which, as  Eric mentioned, helps retain initial velocity.

I cant remember where I saw it years a go but some turkish flight arrows actually had a small piece of lead added to affect the balance point of the finished arrow, which presumably helped the aerodynamic attitude of the arrow downrange when velocities are low.
Title: Re: Spineing a flight arrow
Post by: bjrogg on October 06, 2024, 05:13:39 pm
I know pretty much nothing about flight arrows Arvin. I sure would like to learn about them though.

I asked questions about them in the arrow section but didn’t get much response.

If I’m looking at your spine tester it seems different than any I’ve used. If I’m seeing it right the arrow under  pin 1 and over pin 2 and then the weight is applied on top of the shaft beyond pin 2.

I can see how a barreled or tapered shaft would be effected by the placement of shaft.

My tester is different. My shaft sits on top of pin 1 and pin 2 and weight is applied in between.

I noticed when I use it for tapered shaft arrows the flex is back further but it still measures the deflection in the center

I like tapered arrows for hunting. You get more weight front of center and the flex point being back further seems to make them straighten out faster.

I know you want the straightening out faster part but probably not the high foc weight.

I can see a real dilemma with flight arrows. Its tough enough with being able to use a high forward of center weight.

I’m sure getting clean straight flight is very, very important and everything we normally do to get it make drag or uses weight forward of center

Hopefully we can all learn something here. I’ll be watching  (-P

Bjrogg
Title: Re: Spineing a flight arrow
Post by: Selfbowman on October 06, 2024, 07:02:03 pm
BJ I bought some 50-60 arrows at the flight shoot a couple years ago. These where made by different flight shooters from the 50’s. Godsey  and Pearson Names are on them. These guys new what they were doing. Beautiful craftsman. The wood in these arrows are hard to get this day in time. That’s why I bought them. Also I could learn from some of the best by examining these arrows. Most where missing fledgling or points and such. I have both spine testers mentioned. Some flight arrows are to short for the Don Adams tester. It’s resting points are 26” inches apart. I have move them closer together to test 23-24” arrows but unsure if this is ok. So where I put the weight seams to me to be important. This is all new to me . Broadhead I have got a grip on but the flight arrows is a different game. It’s amazing how stiff these thin arrows are. I’ve spined and weighed. These arrows as best I can. I’ve got a large range of spine and weights . I can test these arrows through bows but do not want to shoot the flight bows so I can keep them fresh. 
Title: Re: Spineing a flight arrow
Post by: Selfbowman on October 06, 2024, 07:03:47 pm
Pic