Spine indexing.

[enewman]

I've been looking at this. People say floating a arrow will show you the stiff side. I can not make that work. But what I can say if if the arrow rotates at all it has nothing to,do with stiff. It's just heavy on that side.

I will test some of this hopefully tomorrow. But. If you spine index. And find the stiffest point. It will be the same 180 degree. Not weak at 180. The weak point will be 90 degree.

Meaning if you find the stiff side and set at 12 then it's the same at 6. So weak point would be at 3 and 9.

If this is correct. Then if you set center shot. Set stiff at 12 or 6. And you shoot the arrow and it has a left tear. That does not have to mean it's weak. It means that the arrow is not coming of the bow in a straight line.
I have a lot more thoughts on this. Need to do a little more research on this.

[enewman]

Well got my bearings in. Just spine tested a couple of my blackeagles. Not sure if spine indexing needs to be done on them arrows. I only had about a 1000 variance on the two I tested. Now on my velocitys. I had over 10000 variance. Going to try flo testing ( I just learned about)to compare to spine indexing. Then shoot and see what happens

[muddyfuzzy]

Well got my bearings in. Just spine tested a couple of my blackeagles. Not sure if spine indexing needs to be done on them arrows. I only had about a 1000 variance on the two I tested. Now on my velocitys. I had over 10000 variance. Going to try flo testing ( I just learned about)to compare to spine indexing. Then shoot and see what happens

I wouldn't tell you wrong That's the whole "spine/weight matched" thing they do............ awesome isn't it.

[let it fly]

Me too!

I just order mine from South Shore

[enewman]

I wouldn't tell you wrong That's the whole "spine/weight matched" thing they do............ awesome isn't it.

Yes it is. I blame you for not telling me about them years ago.

[muddyfuzzy]

Yes it is. I blame you for not telling me about them years ago.

Xena?

[enewman]

Xena?

Yep. She's my hero. Plus the statement on the pic is main reason I used the pic

[muddyfuzzy]

I always thought she was kinda hot myself.....

[BTGuard]

I wouldn't tell you wrong That's the whole "spine/weight matched" thing they do............ awesome isn't it.

Do they do this for all of their shafts?

[muddyfuzzy]

Do they do this for all of their shafts?

only the higher end shafts. they do however measure straightness across a 32" shaft which is much more conservative than the rest of the industry which is why after they are cut far exceed the posted rating of each arrow, this is done on all of them.

[Pushbutton2]

So whats the better spine to have?

One side ie Gold Tip
Or
Spine/weight matched?

The context of my question is in how they each recover after being shot and how they react upon impact.

Along those same idea?
Is there a way to determine where that spine the spine is when it impacts the target.
Is it better to be up, down, or on the side the aid in penetration.
I have no idea if Dr Ashby covered this is his study.

[hoyt21]

Stiff up

[bowhuntntxn]

So whats the better spine to have?

One side ie Gold Tip
Or
Spine/weight matched?

The context of my question is in how they each recover after being shot and how they react upon impact.

Along those same idea?
Is there a way to determine where that spine the spine is when it impacts the target.
Is it better to be up, down, or on the side the aid in penetration.
I have no idea if Dr Ashby covered this is his study.

With a rotating shaft, and varying distances it is impossible to predict the stiff side location upon impact, or how it affects anything downrange.

It more than likely was not addressed because it has no measurable impact, and does not change the total mass or velocity, and thusly not change the KE or momentum. Spine is not a part of the equation to which you so desperately seek a divine solution!

[Pushbutton2]

With a rotating shaft, and varying distances it is impossible to predict the stiff side location upon impact, or how it affects anything downrange.



It more than likely was not addressed because it has no measurable impact, and does not change the total mass or velocity, and thusly not change the KE or momentum. Spine is not a part of the equation to which you so desperately seek a divine solution!

:thumbup:

[enewman]

Sorry guys. I just put a monkey wrench into spine indexing

spine indexting flo testing what are we really doing. i have found a problem. its not what or how, but what we think we are doing.

lets look at a ram tester. it was design to test the spine of an arrow. some where we came up as using the spine tester to locate the stiff aand weak point of an arrow. this is where the problem starts. the static spine of an arrow is what the manufature has design that arrow to be. there is no stiff or weak point in that arrow. if you check what the spine of that arrow is, with a tester it will be the same 360 degrees.

all arrows are built with a straight tolerance. this is generaly .001,.003.or .006.

lets start with a .006 this means the arrow has a bow or a arc in it. when you put the arrow in a spine tester and index it. what we see and call a stiff spine is really just the high point in the arc. this has nothing to do with how stiff or weak it is.
this is why when you check a .001 arrow you will see a wider portion of the arrow at the same reading. the arrow is straighter.
all of this is very easy to prove.

the flo tester. some say this is better then a spine tester. this is incorrect statement. and again can be tested and shown.
what you are doing when flo testing is looking for the laser to draw a straight line. now here comes the good part. all the flo testers have came on here and stated that it will not be the same as the stiff point of the tested arrow with a spine tester. this is correct it will not. now this is why. first i have shown that there is no stiff or weak point in an arrow just a high low point. this is the arc of the arrow. if you line this arc up and flow test it will have a hard time flexing againt the arc. so what they are doing is rotating to what they call the neutral point. this is not a weak point or stiff point this is just not in the arc of the arrow. so the movement at flex now will be easy.

all of what im saying is not theroy. i have tested it. and its very repetable.

all of my spine testing to find the high point is done with a .0005 indecator.



i have done a lot of testing. i can show you and prove to you what i have done