Checking Spine w/ Spine-O-Meter...?????

[snag]

Question...when checking spine with my new favorite toy, the Spine-O-Meter, I noticed something.  If I would turn the shaft so the grain is running horizontal the spine was up to 8 lbs. less than if I put the grain running vertical. Say from 68# to 72#.  Being as the arrow flexes against the grain (grain is horizontal on the bow shelf so nock is perpendicular to the grain) going around the riser I am assuming you take the spine reading with the grain in the vertical position...? Is this clear...as mud?

[Bjorn]

Thanks Snag I knew what I was doing till reading this!! LOL!

Grain in vertical orientation is correct.

[snag]

LOL, so did I until this came up!  Thanks for the clarification.

[aromakr]

Snag:
You are correct that the edge grain should be verticle when taking a spine reading, however your reason for doing it that way is wrong. The position of the grain is part of the spine standard and is the way shaft manufactures should spine their shafts. That way the consumers will know what the spine of that shaft is when the nock is placed correctly on the shaft and they are purchasing spined shafting. Back in the early days when a bowhunter purchased shafts by the dozen or 100 the archery shop would have spined all the shafts before sale and grouped them by deflection or bow weight. You did not have to worry about the spine being different if you oriented the nock to the spine standard.

It is true that some shafts will spine differently as the grain orientation is changed on the tester, however those instances are usually not common. In my exprience its extremely rare for the spine to increase when the orientation is changed from verticle to horizontal, it usally goes down in spine.
Bob

[Bjorn]

Darn, I thought this was gonna not give me a headache.............Cupcake, it is time for you to add to this soup!

[snag]

I concur! Got to let my limited number of brain cells rest now..... :0)

[DesertDude]

I'll give Kevin (Cupcake) a call and let him know.

[Cupcake]

I have not much to add here.  The wood is stiffer when the force is applied parallel with the grain.  Woods are measured with this orientation so that the  batch of shafts are the same, as aromakr said.  When installing the knocks make sure that they are all oriented the same way to the grain.

This is also an opportunity to adjust the spine a bit; if you would prefer a weaker spine to better match your bow I see no reason why you could not orient the knocks for weaker.

DesertDude tests all his carbons for the same deflection and installs the knocks in the required orientation to get the same spine.

[snag]

Interesting Kevin. I have never heard this before. So if I have a few that are 72# and the others are 68# I can just rotate the nock a little and get them to come down to 68#. Brilliant! I would imagine I should rotate and check the spine on the Spine-O-Meter to see how far to rotate...?  I have a batch of arrows in the making. I will do exactly this! Thanks.

[aromakr]

snag:
What Kevin said is true to a point, however not all shafts will vary in spine at various spots on the shafts and some will vary a great deal.
Bob

[dino]

Thus the nature of wood.

[R. Combs]

The problem with rotating the shaft is more of a safety concern than anything. Wood arrows should be built so that the rift on top of the arrow points toward the point end of the shaft so that if the shaft breaks, it breaks up and away from the hand. That being said, A arrow that is built for a right hand shooter should not be shot by a left hand shooter as you are turning the shaft over to have the cock feather pointing out and the rift on top of the arrow would now be pointing to the nock end of the arrow and if it broke it would break down and toward the hand.
Rick

[Jim now in Kentucky]

Rift, shrift. I make my shafts and there IS no rift. A growth  ring  runs the full length of the arrow without runout.

I would probably never buy a shaft that didn't follow a growth ring like that.

Guys who make  shafts  from  tree  shoots don't have  rift to worry about either--no  grain orientation either.

[Bjorn]

Thanks Snag-before you started this thread I had it all figured out-maybe aluminum would be OK after all-this wood stuff is getting so complicated! LOL!

[R. Combs]

Rift is the feathering of the wood on top and on the bottom of the shaft and runs in opposite  directions, It doesn't mean that the edge grain doesn't run the full length of the shaft.

Rick

[aromakr]

Bjorn:
Nothing complicated about wood, just some try to make it more complicated than it really is. I wonder how those that came before us ever got an arrow to shoot (before spine testers) You know Ford and Duff just flexed the shaft in the hands and had no trouble with that working. Even bows cut less than center DO NOT HAVE TO HAVE EACH SHAFT SPINING EXACTLY THE SAME. I hate to shout but it seems people don't listen. I've been at this game over fifty years, believe me. And with the modern bows cut too center and past you have alot of spines that will work in the same bow, and hit in exactly the same spot!!!!
Bob

[wtpops]

Man i dont even use wood and i got a headache

[Jim now in Kentucky]

Eggzactly what I said. There is no "feathering" on my shafts because I follow the growth rings in cutting the squares from which I make the arrows. There is seldom a growth ring that runs out in the length of my arrows. Even less often more than one.

[snag]

I didn't mean to start this kind of a conversation...just thought it would be fun to get some input on how to proper spine a shaft..vertical or horizonal grain. This had not come to mind until recently. Now that I can spine or check arrow shafts that have been spined it brought up this question. Yes Aromkr I can shoot many different spined shafts through my Blacktail recurve. I was just trying to see if I had arrows that were close in spine and weight how much difference it would make in my hitting the intended target...or if it really didn't make all that much difference. Part of this is that I have been shooting carbons too. Now I am trying to get the woodies to be as accurate as possible. I enjoy it. It is my way of experimenting on a small scale I guess.

[R. Combs]

Sorry guys I wasn't trying to cause any trouble. The only reason that I even brought it up was that I had a arrow that broke while being shot and nicked the top of my hand. I did a little research and found a couple articles on rift and it made sense. If anyone has a copy of T.J. Conrads " The Traditional Bowhunter's Handbook " he has a short piece on it on page 147. Sorry snag, I wasn't trying to highjack your post. There are people on here that have been doing this a lot longer than me and I do value there opinion.

Thanks,Rick