Primitive Archer

Main Discussion Area => Arrows => Topic started by: logan6742 on March 02, 2014, 11:43:49 pm

Title: What is arrow spining?
Post by: logan6742 on March 02, 2014, 11:43:49 pm

I'm planning on getting into making my own archery equipment. I have plans for what I will do for arrows, but I have one big question, how do you spine arrows? I understand that the spine of it is how much draw weight it can take from a bow, but how do you know it's spine weight, and how do you get it to your desired weight? Also, is spining arrows even worth it? If someone could give me a brief summary on what it's all about I'd really appreciate it. Also, if you could post a link of a how-to for arrow spining that would be great.

Title: Re: What is arrow spining?
Post by: Mohawk13 on March 03, 2014, 01:49:27 am

Youtube has some great videos. Spine can be determine with a spine scale or purchase shafts already spined...

Title: Re: What is arrow spining?
Post by: Pat B on March 03, 2014, 10:19:12 am

For an arrow to shoot properly it should be matched to the bow and your shooting style. Spine is a measurement of the arrows deflection when shot. To measure this by AMO standards the shaft is placed on two uprights, 26" apart with a 2# weight hung from the center of the shaft. The deflection(bend) of the shaft is measured against a spine chart to determine the arrows spine. For this AMO measurement you start with a 28" arrow with a 125 grain point. For each inch over 28" subtract 5# of spine weight or add 5# for each inch under 28". For every 25 grains of tip weight over the 125 grain you add to the 125 grain point subtract 5#  of spine weight and the reverse for 25 grains under the 125 grain.
  There are quite a few homemade type spine testers on the web. I built mine from JamesHillSpineTester I found on Google.

Title: Re: What is arrow spining?
Post by: Grasshopper Mouse on March 03, 2014, 01:22:55 pm

Spining the arrow is essential to good arrow flight. You can't see it very easily with the naked eye but the arrow flexes wildly when it is loosed. Take a look at this slow motion video and you'll see it:
http://www.youtube.com/watch?v=96KGWC0PB6s&list=TLZUlDXn_25A8

The arrow's spine measurement is basically a measurement of its flexibility. As Pat said, that flexibility needs to be matched to the bow's power and a number of other factors. If you don't use a properly spined arrow you will likely be doomed to poor arrow flight and quickly frustrated in your archery goals.

Guy

Title: Re: What is arrow spining?
Post by: bow101 on March 03, 2014, 04:07:22 pm

I know a lot of guys wing it.  Made some arrows that were to heavy and were shooting to the right. They were 3/8"  lol......... finally made some 11/32" that cured the problem, as I pull about 45#.
Here is a spine jig scale, you will probably have to re-size it.