assembling carbon arrows

[Over&Under]

[Rob DiStefano]

Originally posted by Ray Hammond:
... Are you cutting the shaft length down? Bows cut to center? ...

all my arras are 29-1/4" from the depth of the nock throat to the front end of the cut carbon shaft.

all my longbows are a fat 1/8"+ off center.

[Ray Hammond]

OK, so you are buying the lower spine shaft, cutting length off which makes them stiffer, then adding weight to reduce spine again.

Got ya.

I leave mine full length until I get the tip weight where I want it, then if its too low in spine I just reduce tip weight a little at a time to make it right, or cut it 1/4 inch at a time to make it work right.

[Rob DiStefano]

in the past, arrow spine (i.e. woodies) was calculated from the shaft's center (2# hung weight) as supported at 13" on either side of that center (26" spine length).

most modern shafting (alum and carbon) uses either 28" or 29" for a measured spine length.  maybe. i think.  i truly wonder if the carbon makers even know.  

imo, not an issue for alums as the easton charts are pretty darned good, overall.  but carbons?  no way, jose.  we're all on our own.

take from that what you will.  my final assessment is that carbon shaft spine is pure voodoo mojo mumbo jumbo, at best - and doing yer own testing is what's needed to get an arra that'll fly at it's optimum (again, for you and a particular bow's parameters).        

postscript - i want to use a particular arra length, not one dictated by resorting to it being longer just to drop the spine.  if that were the case, i'd be shooting danged spears instead of arras.  a full length .400 flew decent for me, but no way am i gonna shoot such a long missile.    :D

[Ray Hammond]

well, I always try to leave them full length just because it means I was able to get a little extra weight.

Don't misunderstand...there's a hundred ways to skin a cat....and I certainly am not young and dumb enough to think my way, or any other way for that matter, is the only way to get where you want to go, Rob.

I'm just trying to learn how YOU got there is all, buddy.

I'm looking forward to seeing a pig with one of your arrows through it in a month or so.

[Rob DiStefano]

yep, that's exactly where it's at, ray - lotsa ways to make them arras fly well for each of us.  not rocket science!    

since i don't hold much past 55#, and since i like high foc, it was good that i could start with a light carbon shaft (7.3 gpi), then pile on the front end weight to up the total arra weight beyond 10 gpp.  so, it works out fine ...

29.25" beman ics 500 + lo-pro banana 4-fletch + bohning sig nock = 235 grains

100 grain brass insert + 125 grain steel adapter + 125 grain woodsman = 350 grains up front

total arra weight = 585 grains, 29.35% foc.  

life is good,  :D

bring on da pigs!  please!  :cool:

[Rob DiStefano]

Originally posted by Mo. Huntin:
Rob we are going to need a picture or atleast a good explanation on the slip on nut thing it sounds handy.

the nut job, for adding front end weight ...

the id on an 8/32 nut measures .150, the typical stud on a screw-in point measures .200, so i'm gonna use a .218 drill bit to open up the nut's hole a smidge ...
 

weighing the unmodified nut ...
 

drilling out the nut ...
 

weighing the modified nut ...
 

adding the 19 grain nut to various points ...