carbon footing question

[Alexander Traditional]

The first number is measured in 64's making 2216's 22/64 in diameter. and they are .016 in wall thickness. The 2117 and 2114 are the same diameter but the 2114 is thinner making it go on easier.

[xtrema312]

Once you pick your outside diameter you then change the wall thickness to change the inside diameter.  Given the same outside diameter, a thicker wall will make for a smaller inside.  So a 2216 will fit looser than a 2217.  A thicker wall should be the more durable footing I would think given it is trying to resist splitting.  

If you figure out the ID of these different shafts you can see where you are and then calculate ID of other shaft options to find a likely candidate.

[xtrema312]

If you are going to use the 2117 and it will not quite fit then I would work the inside a little.  I use a rat tail file on all my footings to take off the bur plus thin it down if needed to fit.  Chain saw file is the same kind of thing, but the rat tail I have is a little larger so works more of the inside, and I think keeps it a little more uniform.  

If you have to expand the footing to fit, I would lightly sand and clean off the outside of the shaft in the footing area and then just use hot melt glue on it.

[xtrema312]

Are you sure you shouldn't be trying at 2217 instead of a 2117?

It has been a long day so not sure these are right, but here is a shot at it.

2117 is 21/64 =  0.328125 OD  – (2 x 0.017) =.294125 ID

2213 is 22/64 =  0.34375 OD  – (2 x 0.013) =.31775 ID

2215 is 22/64 =  0.34375 OD  – (2 x 0.015) =.31375 ID

2216 is 22/64 =  0.34375 OD  – (2 x 0.016) = 0.31175 ID

2217 is 22/64 =  0.34375 OD  – (2 x 0.017) = 0.30975 ID

[58WINTERS]

I've used some old 2115's over GT 35/55 expedition hunters perfect fit.

[Keefer]

All I know is I got my 2117's glued on my 15/35's with No problem what so ever...It's good to know there are several other sizes that work just as good so a 15/35 and a 35/55 G.T can take about 4 different aluminum footings so the choice is with whatever you may have or can get..I was fortunate to trade some Easton nocks for some 2117's and all went well footing mine...
 I had found I had to deburr them well and chamferr then run the bore brush through for a clean fit...I am no expert on Aluminum sizeing charts but somewhere I found a chart Charlie Lamb had made up with what shaft size fits what carbon and from that chart and a friends advice I chose the 2117's..
It worked well but if I had some 2216's like Shawn told me to try I would of went with those but my trade was alredy in the making at the time...
Thanks to Shawn and everyone helping myself and those that were asking and letting us know what worked for them...  

[Spurs]

Well, I will ask it?  What aluminum for 55/75's?

Does the footing change the spine any? Will I have to re- bare shaft?

[JimB]

"Well, I will ask it? What aluminum for 55/75's? "

The closest fit would be 2219(.3058" ID) but 2216(.3118 ID) would probably work but would be a looser fit.

A one inch footing shouldn't change things.It isn't longer than the insert so it doesn't stiffen anything and the weight will be 10-13 gs,depending.I also put a 1/4" footing on the nock end.That both strengthens the nock end and also offsets the weight of the front footing.

[ronp]

That sounds about right, JimB.  I put about
1-3/4" to 2" footings on some aluminum arrows and it stiffened them up.  I should have stuck with 1 inch or a little less.

[JimB]

Here is a chart that shows inside diameters.If you can find or measure your carbon's outside diameter,you should be able to pick the closest available aluminum shaft.
 

[Spurs]

Thank you for the info.  I am hunting for some aluminums now.

Tom

[RM81]

I use 2117's on 3555 GT trad blems, and 2216's on 5575 GT trad blems with no problems whatsoever.  I use a deburring tool on the aluminum and they slide on smooth and fit snug.

[rockkiller]

Finally got my hands on a 2219 and that did the trick for the gt35/55s