Arrow spine

Message

Jackrat · #1 Post by **Jackrat** » Thu Aug 28, 2003 5:28 pm

I am off to buy some arrow shafts in a few days.
Now, I intend to taper both ends to create barreled shafts, but I am not sure how this will effect the spine.I am planning to taper the front six inchs and the rear ten inchs.I am not sure if I should buy shafts that are spined for my bow weight or buy them over spined and then reduce the barrel section to the correct spine after I have tapered each end.
Any ideas.. Thanks guys,,Jack.

#2 Post by **Stickbow Hunter** » Thu Aug 28, 2003 8:24 pm

Jack,

I don't think you will lose much in spine weight by tapering them in the manner you say. I would think you will only drop a couple of pounds at most. Glenn might chime in here as I think he plays with tapered arrows a fair bit. Jeff

MIK · #3 Post by **MIK** » Thu Aug 28, 2003 10:30 pm

howdy doody Jack

i have only just started shooting a longbow however i purchased 2 dozen copperhead arrow shafts which are a barreled shaft. they are also spine tested and each shaft is marked with the grain weight.

they come in packs of 12 and the grain variation for each of my packs was only 7 grains. which i thought was rather good

i have been shooting what i consider to be pretty good with them and recomend them highly.. they are also made here in Victoria - yes thats right south of the border

good shooting
MIK

Glenn Newell · #4 Post by **Glenn Newell** » Thu Aug 28, 2003 11:00 pm

Jack, barreling your shafts will weaken the spine, (that's static spine as read on a spine meter) of your shafts a couple of pounds, but the dynamic spine ( how much the arrow bends when being shot through the bow) will be stiffer because there is less mass weight in the arrow, so that should counter act the effects of barreling. I would just I always start of with the normal weight shaft....Glenn...

Jackrat · #5 Post by **Jackrat** » Fri Aug 29, 2003 7:26 am

Ok all good info guys,I will be placing all your replies in my folder of arrow
making skills.I knew there was a relationship between static and dianamic
spine,But Errrrr well,I can lift heavy things,Ya know.

Thanks again,,Jack.

erron · #6 Post by **erron** » Fri Aug 29, 2003 9:14 am

I'm hoping Glenn will expand on this issues of dynamic spine soon

Erron

Dennis La Varenne · #7 Post by **Dennis La Varenne** » Wed Oct 01, 2003 3:01 am

Erron,

I have posted a bit on dynamic spine on the thread about Tusker Concordes which Glenn Newell may like to review.

He is correct in his explanation of the two terms.

Static spine is what is registered on a spine jig and dynamic spine is its actual behaviour in the bow up until it straightens out its side to side flexing motions (paradoxing) after it has left the bow.

The two are not the same and static spine is only a guide to how an arrow will perform in flight when launched from a bow of 'x' draw-weight, but is not definitive.

Dynamic spine (how quickly an arrow recovers from paradox motion) depends among other things upon static spine, arrowhead weight, shaft taper, the elastic mechanical properties of the wood, shaft diameter, limb speed of the bow and bow draw-weight.

Dennis La Varenne

erron · #8 Post by **erron** » Wed Oct 01, 2003 8:31 am

Thanks Dennis, I've just read the other thread and replied there too.

This subject would make an article for the Lore & Legend pages, if one of you can find the time and energy to enlarge a little on what you've said here. Maybe a photo or 2, though I don't know how you'd incorporate them in a discussion of static spine?

Thanks again, you blokes are a goldmine of info.

Erron