spining arrows

[ozzy]

just wondering if i spine an arrow at 27" for argument sake but i use arrows say 28" long obviously the spine would be different would that make that much difference or not and is there a way i can work out how to calculate the difference
because i work out all my arrows for 28"
bit hard to explain what i mean hope youse can make sense of the question im asking

cheers mick

[Stickbow Hunter]

Firstly are you using a spine jig? If you are the reading you get relates to an arrow 28" long to the back of the head. When you buy shafts the stated spine is also for a 28" arrow.

When spining an arrow the shaft is placed between two uprights 26" apart and a 2lb weight is hung from the shaft and the amount of deflection in thousands of an inch gives you the spine reading for a 28" arrow.

As a general rule if your arrow is an inch longer than 28" (29") you need an extra 5# of spine and if it is an inch less you need a spine range 5# lighter.

I hope that helps but if you need further info please holler.

Jeff

[ozzy]

thanks jeff you have answered my question...... i bought one of forro's spine jigs and a good piece of kit it is too
i have measured it and it comes up as 26.75"
so from what you have said that equates to a 28" arrow spine or there abouts
my draw is 26" but i use 28" arrows and base everything of that
its just that i have spined some 1916 allums and they come up as .510 on the jig when most charts say they are .620 not that i pay that much attension to some of the spine charts and these 1916 shoot pretty good out of the bow but most spine jigs base everything of a 125gr head i think where im using 160gr tuskers

cheers mick

[Stickbow Hunter]

its just that i have spined some 1916 allums and they come up as .510 on the jig when most charts say they are .620

The reason for this is maybe the following. Some years ago Easton and other arra shaft manufacturers changed there method of spining their arras to suit the compond brigade. I believe they went from using the 26" between the uprights of the spine jig to 28". I think that is a standard for synthetic arra shafts now days. I only use woods so not 100% on this.

Jeff

[longbowinfected]

As usual Jeff you are spot on.

Ozzy,
If you make timbers that match the same spining after playing with length and points you can be pretty sure they if the same overall mass will fly basically the same with the same gaps or instinctive technique with minimum adjustment.

Spining jigs and scales are really important when making serious arrows that do what you want them to.

Kev

[ozzy]

. I only use woods so not 100% on this.

Jeff[/quote]


thats what im aiming for to use woods but having trouble finding the right ones

kev thats my aim find an arrow which shoots good then find the equal in wood arrows i have found the allum i need the wood now

[longbowinfected]

Try a lot of different lengths and head weights without feathers first.
Good plan and should work well. I found for bows under 50# that at near centre shot for me without overhang at 27.5 inches that I needed 5 pound under recommended spining for alloys and that 1916, 1913, 1914 worked best with 145-175 grain points. If i got them to near 10 grain per pound draw they worked well even out to 60 metres and it made it easier to match the overall timber mass.

When i went to timbers I used 5/16 for less drag with the heavy shaft and used 100 grain points screw on stainless to get as close to the alloy overall mass. Tune from there. Use screw point adapters on your first few timbers so you can try different point mass.

Kev

[ozzy]

Try a lot of different lengths and head weights without feathers first.
Good plan and should work well. I found for bows under 50# that at near centre shot for me without overhang at 27.5 inches that I needed 5 pound under recommended spining for alloys and that 1916, 1913, 1914 worked best with 145-175 grain points. If i got them to near 10 grain per pound draw they worked well even out to 60 metres and it made it easier to match the overall timber mass.

When i went to timbers I used 5/16 for less drag with the heavy shaft and used 100 grain points screw on stainless to get as close to the alloy overall mass. Tune from there. Use screw point adapters on your first few timbers so you can try different point mass.

Kev

kev at the moment im using 1916 allums @28" with 160gr b/h and im happy with the way they shoot they come up as 479gr total arrow weight out of a 45# recurve bow 10.6gpi would like to find the equal in woods

which i hope is enough weight for pigs

cheers mick