Am heading to The Footed Shaft tomorrow to pick up some Cedar Shafts and have a question about spine loss when tapering the shaft.
Am planning on making a set of breasted shafts with 10 tapers on each end. Going to start with 23/64" shafts, taper the nock end with a 10" taper down to 5/16" and the point end 10" down to 11/32". End result wanted to be a 63# spined shaft 29" BOP.
Question is how much spine weight should I expect to loose when tapering the 10" tapers?
I lose about 2 lb with a 10 inch nock end taper and I guess you would lose maybe a pound more with the front taper. Most of the spine is in the middle of the shaft.
1-2 pounds. Essentially you are tillering the arrow a little-lightening the ends and maybe speading the bend a little more evenly-A a matter of physics the middle gets the highest load when bent and you aren't changing anything there so th echange instatic spine is small. On the other hand as you lighten the ends you are dimishing the inertia there and aiding the recovery rate --- effectively increasing the DYNAMIC spine. it is pretty much a wash as far as effective spine goes.
All the bending ocurrs in the middle. Tapering the ends won't matter more than a #, maybe 2.
Bucksnort:
If you are going to taper 10" of each end you will have a Barrel taper not a breast taper, and if the tapers are straight you will loose quit a bit of spine. Keep in mind a 28" arrow will have only only about 6 1/2" of parallel shaft after nock and point tapers.
Breast tapers have different lengths of taper, i.e. a shorter taper on the nock end and the longer taper on the point end, And usually dissimmilar diameters i.e. smaller dia at the nock larger at the point.
Bob