Shannon, A quick, simple way to get in the Ballpark on the spine is to ,Take a 20 oz Coke bottle and fill it with water. Wrap wire around the top and bend a hook in it. Take an arrow you know what the spine is and suspend it on two nails about 28" or whatever,depending on the length you shoot apart. Mark where it bends to, and mark the spot. Then just test the rest. If you don't have a cane arrow splined like you want, make a cane arrow that shoots good and use that for your control arrow.