cutting to stiffen carbon shafts

[dick sable]

Thanks very much for the offer Todd. I do have half a dozen new 55/75 shafts. I'll give that combo a try.

[dick sable]

Steve,
I've heard that before re the weight tubes. I guess I'd rather keep the weight up front anyway. I have a variety of potentially "experimental" shafts already cut but they have aluminum inserts glued in with non heat reversible powerbond. I hate that stuff. I'd rather use 100 gr. brass inserts. I now have Bohning's "Insert Iron" which is supposedly heat reversible.

[Dean Lintz]

I have to agree with starting with long shaft and the point weight you want to shoot. Then bare shaft tune cutting small amount at a time. This can be a lengthy process but worth the time. The over all finished length is not as important as flight to me.

[metsastaja]

I use Stu's Dynamic Spine Calculator when messing with arrows weights and bows. The center cut of your bow will effect spine greatly. Changing from 0 center cut to +1/8 lowers spine to 56.2

Gold tip specs are.


Spine is ASTM. AMO spine for 3555 is 63 for the 5575 it is 78.8


Here is what your set up came out as.  Best of luck

 

[Traditional-Archer]

One thing we all have to remember is, while we want a reasonable FOC or even a good EFOC one of the key factors in finding this, is a light weight high spine arrow. This will require more weight upfront to weaken the spine and fly true of you rest.
I have messed around with weight tubes, it's just my opinion but they only add more problems to the equation of trying to find the right spine arrow weight. Anything we do to an arrow or our bows will affect the arrows spine (any changes we make).
To find the perfect arrow for your bow takes some work, start from the beginning and don't take shortcuts. Go through the numbers one by one taking baby steps. If you try more than one thing at a time you end up getting lost and will not know what worked and what did not. If you have time and money you will get there, but I like to think you would like to find a solution in half the time and spend a fraction of the money.

Bruce  

[Quinn]

Go with what George said. Let the arrow tell you the right length. In the long run you'll be real happy you did it that way. I did it the other way 1st time around and ended up with a dozen useless arrows.

[LKH]

I just finished bareshafting and fletching some GT 35/55's.  I'm shooting them out of Jack Harrison's new composite handle takedowns.

Bow 52# at my 26" draw.  Put 100 grains brass and used 125 tip.  Ended up w/28.2" from nock bottom to end of the brass.  

They fly like darts.  

I follow what George says.  I put the insert in, screw in a tip, and start cutting until I get a slighty weak bareshaft.

These will be about 470 grains which is great for my spot and stalk style hunting for deer, antelope, and caribou.

[LKH]

I got an FOC of about 21.4.  I think they will blow right through a deer and be sticking out the far side of a caribou.

[MarkE2006]

I am not sure why so many think because their draw length is "X" that the arrow has got to be "X+1".  My draw is 28" and I'm shooting 30 1/2" arrows and even some at full length of 32".  Both of the lengths of arrows have a dynamic spine about the same.

If your recurve is cut to center it will be very forgiving of a wide spine range.  If it is cut past center your arrows will need to be stiffer.

Good arrow flight is the goal, not meeting an imposed length requirement.

Stu Miller's dynamic spine calculator is a great resource.

[LKH]

MarkE, I've got some CX that are 29.5" Stick out a long way.  It's all about getting the right spine. Plus, I don't want an ounce of weight up front.

[dick sable]

Thanks guys for all your help and time.  Steve, it has been a tortuous process. Reminds me of when my '67 Ford Falcon sputtered along, terribly out of tune!  More information later -  when my head clears.  Mark, gotcha! Again, thanks gents!
Dick

[Dan White]

Hey Dick Sable,
   
Quote;
"shafts already cut but they have aluminum inserts glued in with non heat reversible powerbond."

Is the non heat reversible powerbond the same stuff used in carpet installation. Does it come free of the carbon arrow very easily

Thanks, Dan

[dick sable]

Dan,
I mailed you.  I'm sure you'll get alot of info here on glue for inserts and removing them. Not really sure what most folks use for their carbons.
Dick

[NDTerminator]

Originally posted by George D. Stout:
Them babies at 27" are going to be about 60#'ish spine, as I believe they are spined at 28" from the factory.  That would normally indicate a 55# @ 28" on the 35/55.  Carbon stiffens quickly when cut shorter as well so I would suspect they would be very stiff for your bow....unless it's cut past center.

You really need to take a shaft and experiment with the front weight you plan to use.  Don't guess; start at full length and work backwards, cutting only about 1/4 to 1/2 inch at at time.

Concur...

I highly recommend you download Stu's Trad Spine Calculator to assist you.  This is the best thing to happen to Trad since the Big Shot Glove.

Using it, I was able to achieve perfect flight with 29.5" CXTH 4560, from my recurves that average #53 at my 28.5" draw.  to get under 2# difference across the board, I had to go with 145 grain points with standard inserts, or 125s with 50 grain brass inserts.  If I cut the next batch to 30" though, they will be virtually on the money.  Could have gotten there by trial & error, but it would have taken longer and probably cost me a shaft or two cut too short/stiff, along the way...

Also was able to get virtually identical dynamic difference using a 30" 2213, 125 grain, and standard alum insert.  I had long since dismissed the 2213 as too whippy for my setups, until I got my mitts on Stu's Calculator to assist me. In short order I got perfect flight with those 2213s, it was just a matter of weight distribution & length increments...