question on footing carbons ....

[Mr.Magoo]

I am going to try footing a handful of carbons to see how they hold-up.

2117's seem to be the size that fits best over the GT33/55's.

Trouble is, the 2117's I have laying about are the "Fall Stalkers", not the xx75/78's.  Since I'm only using a couple of inches for footing, do I need the better alloy shafts or will what I have work just as well?

Thx.

[BobW]

Unless you are like me (ape arms), and actually adding length, all you are doing is re-inforcing the carbon against mushrooming, and just about any wall thickness will do what you are attempting.  Keep in mind, you only really need about as much as the depth of the insert.

[O.L. Adcock]

Keep in mind also you are doing nothing but moving the weak spot behind the insert to another spot depending on how long it is. "Footings" need to be designed like a fishing rod, going from very strong to weak gradually over a distance. Look at a 2 point wood arrow footing, that's the right idea. Sleeves over the outside may reduce mushrooming but it doesn't get rid of the hinge point on a glancing blow....O.L.

[JRY309]

Footing I believe will help strengthen the end of the shaft.I've only footed carbons like Axis/MFX to make a 5/16 point fit alittle more flush and for the strength.With alot of guys shooting heavier points and with the length of them they can put alot of leverage on the end of the shaft on a glancing blow.Most shafts that get cracked ae right on the ends,so footing them has to strengthen that part.The hinge point is moved back but is stronger then it was without the footing,in my opinion.I tried an Axis and put it in a vise and bent it over until it cracked the end of the shaft and the footed one did not crack the end of the shaft when I bent it over the same distance.It did not crack behind the footing either.Carbon Express makes aluminum footing for the nock ends of there shafts for their Maxium line to keep the nock end from cracking.I have seen other carbons crack on the nock end from a hard hit on the front end.

[JDice]

O.L.,

Given your point - is there a method by which a carbon shaft can be footed that is like a 2 point wood arrow footing?

[O.L. Adcock]

JDice, Several ways a fellow could do it and the best way,  I don't know if I should mention yet for taking some of Doc Ashby's thunder. I've used K&S tubing either aluminum or brass depending on how much weight I want up front. Use like a 4" or 5" piece that fits the ID, then a 3" piece telescoped inside that, then a 2", then a 1"...All butted up against the insert. That works just like the fade-outs in a bow, transitioning from strong to weak over several inches. I've also turned down the back half of a brass insert so the internal foot slips over that and is the best option if so inclined.

An outsert type is the same as putting a piece of pipe over a fishing rod and setting the hook. Guess where it's going to break. In structures if you make one section stronger, in effect you've made all other parts weaker.

Carbon shafts mushroom because the insert moves. 2 or 3 or 4" of something glued behind it and it won't move. Shouldn't move even without that if it's preped well before gluing. If it does move it's damaged more then just the 1st 1/4"....O.L.

[JDice]

Interesting. I believe I will try that approach.

Thanks,

[JDice]

Here is  first effort on internal footing for my carbons. Since I can't go hunting today - doing this beats the stuffing out of mowing the lawn.

 

I was going for 125 grains - ended up at 120.

 

Before today, I don't think the staff at HobbyTown had ever had a customer come in with an arrow shaft and ask for tubing to nest inside it.

 

That stub fits the hole in the bottom of the insert.

 

The first one. Now for a little testing - to failure. If all goes well, it is my intent to finalize the lengths of each tube and then produce 12 more  - all weighing 125 grains.

[TomMcDonald]

TTT

[Naphtali]

Many months ago Ed Ashby mentioned that a commercial shaft/arrow manufacturer received his data on creating internally footed carbon shafts, that the manufacturer would/might be making them. . . . Anything?

[Ted Fry]

In a nutshell that is what we did with the Arrow Dynamics arrow when we produced the Hammer Head arrow shaft, beefed up the front 11" with a thicker wall and tapering it gradually to spread the weak point over a longer area. We also achieved the heavy front of center and mass weight I was trying to get , with a standard insert ( aluminum) and a 125 grain point with a 29" arrow we are getting 550 and 600 with a 32" arrow.
With the back being tapered and mass weight at 20% this arrow like all the other ADs are very spine tolerant as well.

[TomMcDonald]

Originally posted by Ted Fry:
In a nutshell that is what we did with the Arrow Dynamics arrow when we produced the Hammer Head arrow shaft, beefed up the front 11" with a thicker wall and tapering it gradually to spread the weak point over a longer area. We also achieved the heavy front of center and mass weight I was trying to get , with a standard insert ( aluminum) and a 125 grain point with a 29" arrow we are getting 550 and 600 with a 32" arrow.
With the back being tapered and mass weight at 20% this arrow like all the other ADs are very spine tolerant as well.

So you used carbon as the 'footing' material?

[Ted Fry]

Correct Tom, also at present working on a new carbon arrow with a little surprise up front , stay tuned, shot a nice whitetail last week with a new proto type carbon with a solid front end.

[TomMcDonald]

Those Hammerheads look very nice.
So are these new ones gonna be even heavier at the front or is the goal toughness? Or both?
Sorry to pry, I know it's a prototype.

[TomMcDonald]

TTT