Picking arrow woods for spine.

[Nephew]

How would one discern the likely spine of arrow shafts cut from a plank (or whatever the correct term is) before you begin?
Like, is there a way to tell before you start ripping your billets, or do you just have to take pot luck on what comes out once down to 11/32nds"(thanks Jeff!) and spine them on one of Forros meters then? That doesn't seem right as you may end up with something spined for 20# when you were after 50#, but what would I know? There must be a way to have an ballpark idea of spine before you start, surely? Is it the type of wood, or density of grain...what?

[rodlonq]

Gidday Moreton,

Have a look at Dave's (Yoeman) post determining the modulus of elesticity (MOE) of a sample.

http://www.ozbow.net/phpBB3/viewtopic.p ... elasticity (sorry, don't know how to quote a url, just cut and paste it from another window)

You could apply this principle to a large plank of timber (say 6" x 2") providing it is long enough to deflect in a manner you can measure, this will give an "average" MOE for the plank.

There is a bit of math involved, but if you know what MOE you need to get your spine right for a given diameter, then you "might be lucky to get some on target spine if the plank is fairly uniform and similar MOE.

Cheers, Rod

[Nephew]

Sorry fellas,I saw how that post wasn't very clear and edited it so's it refers to arrows.
Thanks Rod, do I just apply the same principle for arrows?

[Stickbow Hunter]

Craig, I think you won't know with any accuracy until you cut a blank and make an arra shaft from it and check the spine. Every different block of wood you intend to cut arra blanks from will most likely give you arra shafts of a different spine. I think you meant 11/32" in your post as well.

Jeff

[Nephew]

Your right, Jeff, kinda combined 5/16ths and 11/32nds there, didn't I?

So, basically you just have to try and see? Hmmm, think I may stick to ready made shafts for a while.

[Gringa Bows]

What kind of timber were you thinking of trying Craig

[rodlonq]

Craig, there is some work here (again from Dave) that may help with the arrow part of it.

http://www.ozbow.net/phpBB3/viewtopic.php?f=34&t=9837

Unfortunately Jeff has probably understated the fact that testing a large board may be misleading. Once you cut it up there could be a large variation in MOE of the arrow blanks compared to the average for the average for the whole board. This is the joy of natural products such as timber .....Rod

[little arrows]

Hey Moreton,

Knowing the MOE of any given species will not give you the spine of an arrow, until as, Jeff said, you billet it, then plane it down, then spine it. Then you have the grain variences in different parts of the plank which will give you a wide variety of spines over just one plank of timber.

cheer

sue

[Nephew]

What kind of timber were you thinking of trying Craig

Thing is, Rod, I was going to chat to you about that. Might be off in the future a bit though, mate.
Thanks everyone. It's becoming clear to me I have a fair way to go in gaining experience/expertise in woodworking before I should attempt this.

[kimall]

I think you are over thinking things mate cut some sticks up and see how they go.I just cut some hoop pine boards into squares about the right size and then made them round and then sanded them until the right spine was reached to suit my 55 pound longbow.If they are a bit thick taper the front and back a bit to fit your tips and nicks if the shaft is not an exact factory size who cares if they are all the same they will fly ok.Also I have found the arrow mass does not affect arrow flight as much as spine so if across 12 arrows there is 50 grains difference you can live with that in most cases.As you get better at it they will be more consistent.Hoop pine seems SOOOO easy to work with and spines about right at the right size for 50-55 pound and you can often get it for free when they do house renos as it is in the toung and groove walls.
Cheers KIM
PS Mate if you do get your self up here one day we can rip some up on the bandsaw and show you how easy it is.

[Nephew]

Ok, so it can be easier than it looks? I'll have a chat to Davo and see if he has room on his lounge for me in the next couple of weeks, then take you up on that offer, Kim. Onya.
I only started thinking about doing this after I acquired one of these- http://www.power8workshop.com/index.php as a gift from a partner caring enough to want to help find new interests for me, and she might even end up with a beginner level spice rack out of it or something . Nice of her, huh?
Should be good for the kind of projects I'd be doing... arrows, maybe a case for my "Shoyk" TD LB and arrows, that kind of thing.