Has anybody used the internal point weight and footing jig????

[RRock]

Okay, So I'm a wood arrow junkie, what can I say.

I hope this dosen't fall into the Popular mechanics category.

I'm building a set of arrows that I want to increase my weight up front. I know that by rilling the shaft and adding weight I'll impact the spine of the shaft.

Maybe an exapmle is the way to go.  Now, this is for discussion purposes only.

If I have a shaft that spines 70#'s and is good with my BH weight, I drill the shaft 3" and add weight internally. I know that by adding the weight I will weaken the shaft.  Now, by drilling back 3" and adding 3" of steel wire, will I be effectively decreasing the length of the shaft and increasing the spine because I have stiffened that portion of the shaft?
make any sense? Has anyone run into that and what did you do?

With the price of good cedar today, I don't want to be making a pile of fire starters.
I really don't want to go to hard wood shafts to get the extra weight.

[Benny Nganabbarru]

I've used it, but I don't know the answer to your question. Mine flew well, though.

[DEATHMASTER]

A shaft is over a 28" lenght the three inch you are working will have minimal effect on the arrow.
The weight will act just like a heavy point added.

JMHO
Tim

[Rob DiStefano]

try one arrow and see - it's the only way yer gonna know for sure, for you.  anything else by you or anyone else is speculation.

fwiw. i have no problem adding 60-80grains with hex pine or fir woodies.  ymmv!

[Fletcher]

Rock, I've been weighting some of my wood arrows, too.  I drill the front end with a jig in my drill press.  Two inches is pretty easy and three is about the practical max.  I'm using 1/8" solid lead wire for my weight at 35 gr/in.  Paper tuning tells me that I need to add one pound spine for each 10 grains of added weight.  The added stiffness at the front of the shaft will have a negligible effect on static spine.

So far, 70 grains is about all I've wanted to add to an arrow.  If I want more weight up front or total arrow weight, I'll get it with the broadhead.

I shot a 125 lb dressed pig last month in TX.  My 28" arrow was a sitka spruce shaft, 70 lb spine, with 50 gr lead insert and a 190 gr VPA Terminator.  Total arrow weight was 620 gr. and FOC computed to 20.6%  The bow was a Pronghorn T/D longbow, 58" and 54 lb at 26".  I hit him at the last rib with the arrow stopping at the opposite front shoulder and centerpunching the heart on its way thru.  A similar pig (125 lb dressed) was taken with a very similar arrow with a 70 gr insert and  135 gr Zwickey Delta.  The Delta completely cut ribs on both sides on its way thru.

So far, I'm liking my Heavy Heads.  

[martin guy]

Sent you a PM.

 http://gmsarcherytools.blogspot.com/search?updated-min=2010-01-01T00%3A00%3A00-08%3A00&updated-max=2011-01-01T00%3A00%3A00-08%3A00&max-results=2

Andy

[Renaissance Man]

A question for you fellows doing the internal footing thing, if you are only marginally interested in weight but most interested in strength of your shaft what would you use besides wire or lead?
I figure some kind of hardwood dowel, but am wondering is there something 1/8" that would be much better?

[Zradix]

If you only really want to add strength, try a carbon fiber tube like dragon plate sells or maybe a thin walled steel, aluminum, or titanium tube.

[Jack Skinner]

I drilled and added 2 inch of 3/16 brass about 100grs. I had to up my spine 5lbs to get the shafts to shoot out of my selfbow(from 60 to 65lbs spine) . Selbow is more finicky of spine. I will not do the 3/16 size again. There was not enough shaft left around the brass and mine have almost all broke behind the point at the brass/wood junction. When I try again I will only drill the diameter of the supplied bit with the jig 1/8. Will not get as much weight but should be stronger/more durable.

[Arrow4Christ]

I've found that the weight added actually weakens the dynamic spine a bit, but since you're effectively taking that length off of the shaft, it kind of counteracts the effect and therefore does not weaken the arrow as much as more point weight would. I've found that using the footing option in Stu's Dynamic Calculator for the length and weight of footing I'm inserting into the shaft gets me into the correct spine range consistently.
I agree that going past 3" is a bad idea, as you will lose some shafts doing that by drilling through the walls of the shaft. I personally don't like to go past 2.5" just to be safe. I've got holes drilled into the shaft up to 5" long (which is past the point where these footings stop weakening the shaft and start to make it stiffer), but it's dangerous trying to go that far. These footings are well worth the time and effort putting them in though, as they greatly increase the frontal impact strength of the arrow.


Craig

[Jim now in Kentucky]

Deathmaster is dead on about the stiffness. there is almost no flexing of any arrow in the front few inches. This touches the idea behind barreled and chested shafts. The front can be very much smaller than the middle of the shaft without changing the spine at all.

On the question of adding strength to the pile end of the arrow, the center of an arrow does almost nothing for the stiffness or strength. In bending, something like 90 percent of the resistance to bending is accomplished in the outer 10 percent of the diameter.

If you just want to add strength, I don't think you can do it better than by using a walnut or cherry Reparrow. If I knew of a better way, I's stop making them.

 http://www.angelfire.com/biz/Ironwood/woodbows.html

Jim

[Arrow4Christ]

The reason that it disproportionally stiffens the arrow is the same reason that a shorter arrow acts stiffer than a longer one. The portion with the rod inserted is effectively taken off the arrows length...however, the weight added causes a greater dynamic reaction when we're talking about 2-3" internal footings, therefore slightly weakening the dynamic spine of the shaft, but to a lesser degree than simply loading up point weight.

Craig

[Rob DiStefano]

i've used 3" pf 1/8" oak dowel, or bamboo skewer, or carbon fiber rod - they all do a fine job of stiffening the front end up to help busting off the point.

[RRock]

Thanks for the help guy's, gives me an idea of what I need to do.

Matt

[Fletcher]

If you want to try the lead wire, I have plenty to share.  It isn't as heavy or stiff like the tungsten, but at $1 a foot, at least you don't have to hock the house to buy it.