fletching help

[Dogbyte]

Hey guys. Ive bought a bundle of pretty good quality 5/16 birch dowels for arrows... I figured i'd better practice on these before i fooled myself into buying higher end material, i might find out i dont need to.

But now that i got these 100 36" dowels... the only plan i got so far is to go through, pick the straightest ones, and from them, check that the grain is straight through and doesnt run out somewhere in the middle...

but wont i also need to check for spine, or something else along those lines?  i once heard about taking a good store bought arrow, hang it on the wall with a weight in the middle and mark the sag, then use that as a judge against the dowels...does this seem right?

[Ray_G]

You definitely want to check for grain run out and can straighten shafts.  There is a recent post asking about how guys straighten shafts.

You want to spine check your shafts into groups and then into groups by weight.  With nails 26" apart and using a 2# weight, you could check the relative spine of your dowels.  This will not allow you to know the spine if it doesn't make your mark on the wall.  Why not build a spine tester?  They are easy to construct and there are posts that can be searched for on here that show what folks are using.  I modified a design to accommodate what I had on hand.  It uses a dial indicator and can easily see 1# spine differences.  I used the James Hill spine tester design but modified the setup a little.  Search the web for James Hill spine tester.

 

[Dogbyte]

is the spine poundage always 26" divided by the amount deflected by a 2lbs weight? Is this just the James Hill convention? I guess the use of the 2# weight isnt arbitrary, but meaningful, so the end result of the math means that arrow can withstand that particular bow poundage?  

so 26 divided by .375 is 70.27#'s of spine?

[Ray_G]

For wood shafts that is how it is.  It is an AMO (Archery Manufacturers Organization) standard.

26/spine = deflection in inches.  

In your example .375 is actually closer to 69# spine.

[Dogbyte]

Ok, thank you. Ive got 100 shafts to start testing...

I shoot a 50# Bear Montana, so what poundage is and is not acceptable in yalls experience? Whats best, but also what can you get away with?

I guess i will group the arrows in 5# increments, then by weight. Ill just have to look for the ones that shoot the best...