IMN23D

Help me with my thinking about matching arrow spine. I have an Arizona arrow straightener and I made a 32" channel for it. After I find the " weak spine" side by a previously mentioned " bearing test" method, I can measure the deflection of the arrow (at full length of 29" ) with 2 lb weight. My arrows presently have different deflections with about a .030 difference (i.e. .385-.415) high to low between the dozen. The arrows (CXL 250 29" 80 gr tip) match perfectly on the AA program. I can move the support on my arrow straightner in to make all the arrows match the same deflection. With some of them I have to move the support about 1/4" (telling me my arrow needs to be 1/4" shorter). So, after matching deflection, my arrows will not all be exactly the same length, but will have the same deflection (same spine). I can add some weight to the tip to make the arrows weigh the same. I know they will not be the same as " factory specs" , but they will be the same among themselves. Is my thinking correct, or am I missing something? I just like to play after I' m done shooting.

Start with the stiffest of the group. Then slide support to get the same reading. If the support moved 1/8" then cut arrow 1/8" shorter.
Then add weight to the tip accordingly. Can' t be much. probably around 1 grain.

Rangeball

I' ve learned here that of the arrow specs, Spine followed by weight followed by straightness is the order to consider. Inconsistent spine tolerance seems to be the big issue with cheap to mid-range carbons. Assuming you have a way to add weight to match the arrows and get close on FOC, I don' t think length has much to do with it.

What you' re proposing sounds logical to me. Perhaps you hit on a way to make cheaper carbon arrows work

IMN23D

Anyone else want to reply? Anymore opinions?

Raymond van Halm

Ok.
Let me come back to this.
I have to look up something....

Raymond van Halm

I tried to find back a reply on a topic i placed some time ago.
I cant find it anymore.
Anyway....
In my frinds shop we have a spine tester.
Basicly its just made from the specs Easton gives us.
A 28" span and a weight in the middle, bla bla bla.
After we started using it (its a very precise device) we found some very strange things.
Out of a set of 12 ACC we could match only 6!
Than we found out my favorite Arrow Dynimics scored 10 out of 12.
Same as the Carbon Express did.
Easton aluminum scored 9 out of 12.

Than we decided to take some deeper tests.
We measured a new alu shaft and shot it into a soft target for 10 times.
It was showing lost of strenght allready.
The ACC was going down even faster.
The matrix carbons like Beman, Carbon Express and Arrow Dynamics holded out longer.
After some 50 shots however my AD arrow lost about 40% !

Now.....We wanted to see the difference between a complete new shaft and a shaft that was shot for 50 times.....NOTHING!
Well, maybe there was, but i dont know anyone in this world that could notice.
Same we did with the arrows, new from the box that didnt match the others...
No difference at all..

So dont worry to much about this.

I allways check my new shaft for straitness.......
There is to much diffence in that and this i can see in the results.

Oh, and changing your arrows in leght to match them......DONT !

I hope this can help you.