Aluminum footing question

David lozzano · July 20, 2012, 03:21:00 PM

Does aluminum footing on a carbon arrow affect spine?
I'm planning on using a 2 inch piece of aluminum shaft for footing on my GT trads is this going to affect shaft spine? also can I use JB weld to glue these?

Thanks,
David

KOOK68 · July 20, 2012, 03:23:00 PM

I would think JB weld would weigh much more than the aluminum

huntin_sparty · July 20, 2012, 03:26:00 PM

I am not expert but I understand the footing to increase the spine like it would if you cut the arrow shorter. Ive just used goat tuff glue for the footing and had no issues.

Killdeer · July 20, 2012, 03:29:00 PM

I use Gorilla Glue, and don't shoot we'll enough to tell the difference. I foot them and tune by cutting the nock end until a bare shaft puts bullet holes or is a hair weak in paper at 3 yards.

Killdeer

ron w · July 20, 2012, 04:15:00 PM

I use JB Weld with no problem. A friend uses Loc-Tite. I have used Super Glue and 5 minute epoxy but it did not work as well. As far as spine....I could see no difference.

JimB · July 20, 2012, 04:19:00 PM

The first ones I did,were after tuning.1" on the front and 1/4" on the nock end.They just about cancel each other out.Now I cut to length,foot and tune strictly by point weight.

JB Weld works fine and won't add 2 grs.Lightly sand carbon and footing interior with 220 grit sand paper,clean and glue.Let them sit overnight before shooting.

Reaper TN · July 20, 2012, 04:58:00 PM

I foot my GT Trad 1535 and 3555's with a 1 inch piece of 2117. That 1 inch piece weighs 12 grains. I also sand slightly with some 200 grit sandpaper the first inch of the shaft and use Loctite epoxy to glue mine on. I can't tell any difference in a footed and non footed shaft when I'm shooting.

Blue Tick · July 20, 2012, 05:38:00 PM

Good info here.

Earl Jeff · July 20, 2012, 06:54:00 PM

the footing will not effect the spine in anyway.

adamgti · July 20, 2012, 07:12:00 PM

Think about how long an insert is, if you put 1" footings on your arrow it shouldn't really have a noticeable effect on the spine. I personally use two part epoxy and also add a 1/8" collar on the nock end of the arrow.

don't hesitate to foot some arrows, you really wont regret it at all.

Sand the arrow as well as the inside of the aluminum, it will help the glue stick.

huntin_sparty · July 20, 2012, 10:16:00 PM

Heres a thread discussing the same thing and where I saw it can increase the spine. Also on Stu millers calculator it increases the spine if the footing is longer than the insert you are using.

http://tradgang.com/cgi-bin/ultimatebb.cgi?ubb=print_topic;f=1;t=105726

So 1 inch probably would not but 1.5 or more may.

sledge · July 20, 2012, 10:20:00 PM

is the footing to strengthen the shaft?

i have found carbon shafts amazingly stout!

not arguing, looking to learn.

thanks.

joe

July 21, 2012, 09:32:00 AM

the footing keeps the carbon from mushrooming out away from the insert..
(when you hit something hard it pushes the insert into the arrow)..
and i think the footing only needs to be as long as the insert, anything longer and it will affect spine.

JamesV · July 21, 2012, 04:23:00 PM

I installed the insert into the carbon shaft, cut my footing 3" long and installed an insert in the aluminum footing. I needed the extra weight up front and the double inserts made them bullet proof.

Earl Jeff · July 21, 2012, 06:26:00 PM

Here is a pic of a carbon shaft I was experimenting with footing lengths, The spine of the shaft didn't change from the footing until I got close to a 12" of footing, most of the flex in a shaft is near the center. These arrows continued to shoot to the same point of inpact and flew well right out to 12" of footing. Don't know where stew gets his info from. Just letting you know how the footing worked for me.

David lozzano · July 21, 2012, 11:09:00 PM

Great info, thanks guys!

Blue Tick · July 22, 2012, 01:45:00 AM

I'm planning to foot some arrows myself. Good info here. Thanks.

huntin_sparty · July 22, 2012, 09:37:00 AM

Earl Jeff cant argue with the results from a spine tester, really interesting that you almost need a FOOT to see any change in spine! What I do know first hand is the 1.5 inch aluminum footing I added to a Beman MFX 500 has made the thing almost indistructable, was really happy with the results stumping!

maineac · July 22, 2012, 09:40:00 AM

I tend to shoot with about an inch of aluminum. My arrows have been bullet proof and I figure the shorter length will have less effect on the spine. Though it appears my worry about spine was unneeded. but they stay closer to the same point weight.

hkmp5 · July 23, 2012, 12:09:00 AM

Hello Earl Jeff,
I totally agree that footing a shaft in any reasonable length does not change the static spine, I have never said otherwise. I also agree that the majority of the bending happens in the middle of the shaft when loaded statically and have done similar experiments with my spine tester.
My statements, and the equations developed for the DSC, only relate to dynamic spine. Adding an external footing effectively reduces the usable arrow length and we all know how that stiffens a dynamic spine without any change to the static spine of the shaft. What most people do not account for well in the DSC is the additional weight added up front from the footing material itself. (Basically the footed area becomes a really long point) When this weight, plus the weight of the original shaft underneath, is taken into consideration then there is very little dynamic spine change at reasonable footing lengths. Most of the time the amount of change is well withing the bows tolerance range and no significant change to arrow flight is observed. What does change is total weight and FOC% both go up.
-Stu