Arrow tuning with footing

[styksnstryngs]

As per request of @Red Beard , here's my simplified explanation of how I tune with arrow footings and why it works.

The vast majority of us archers are shooting carbon arrows, and that is what this method is really meant for. Footing an arrow involves a sleeve of metal that fits over the point end of an arrow shaft. The easiest and most common source of this footing is in aluminum arrows, because aluminum arrows come in a very wide range of inner diameters, from .1595"(1214s) to .3803"(2613s). To find what size of aluminum arrow will work with your arrow, find the outside diameter of your carbon arrow and add .007" to find what inside diameter aluminum arrow will work. A difference of .005" might work with a little bit of sanding, but anything upwards of about .0095 is too sloppy.
Basically all I do at this point is cut the aluminum arrow into short pieces with a tubing cutter. A hacksaw works, too. Just make sure you don't crimp the tubing and you should be fine. I then chuck the short aluminum pieces into a drill and square both ends, then deburr lightly. Finally, with a file, I taper one end so it flows down flush to the carbon arrow shaft when installed. You can install these footings with hot melt or epoxy, but since I tune with the footings, I use the blue low-temp hot melt. I've never had an issue with footings coming loose, since there's a lot of surface area for the hot melt to grab.
Tuning with footing length: My method is best used in conjunction with a dynamic spine calculator-- the 3rivers one is the easiest, probably. Dynamic Spine Calculator
I enter my bow specs and build an arrow to get me close to tuned based on the calculator. For me, the calculator is usually pretty accurate, but people with wonky release, long or short draws will probably have to find their form calibration factor. Anyways, you may notice that the spine calculator has a section for footing length. Increasing the footing length essentially shortens the length of the arrow shaft that can flex, making the overall arrow act stiffer. Having a shorter or no footing relatively increases the flexing length of the arrow shaft, which dynamically weakens the arrow. I usually try to find a shaft that will show as tuneable on the calculator with a 1.5" footing, and then adjust the footing length from there.
For example, with my current build, I am shooting recurve that's pulling 48.5# at my draw. I have full length Easton Aftermath 300s, coming out to 32.75" from nock valley to back of point. With 1.5" footings, my bareshafts were grouping noticeably to the right of my fletched shafts. At 3" of footing length, my bareshafts are grouping a hair to the right of the fletched shafts, which is what I want (for a few different reasons.) I don't ever have to cut my shafts anymore, and I can usually use whatever point weight I want, as well. If I wanted to shoot these arrows with 175 grain points, I could just shorten the footings to 1" and get a rough tune.
As a side note, this is pretty much the easiest way to add weight to the front end of your arrow while stiffening spine, an added benefit for me. I don't really seek out extra FOC, but I'll take it if it's given to me as a convenient side effect.
Here's a pic of what the finished arrow should look like (not my pic, btw):

Notice that the field point is the same diameter as the footing and not the original carbon arrow.

Anyways, hope that helps and wasn't too confusing. I can clarify any poor explanations if you have any questions.

 

[Petrichor]

Interesting. Never heard of footing anything but a wood arrow.

 

[Razorbak66]

Yep been doing this for years for my carbons good explanation

 

[PEEJAY]

this also has value for compound bows. I use SS footers to stiffen the front and add FOC (if i use aluminum it will bend pretty easily after a passthrough because of the increased KE). Lets me use a heavier spine than what i would normally need for my 62# DW. Ashby's guidelines work well with modern compounds. According to the G.O.A.T. of FOC, the decreased flex in the arrow also helps with penetration.

 

[will4554]

Seems really convenient to never cut arrows. I've been wanting to try a footer for while, this may convince me to do it.

 

[Razorbak66]

I’m on the other spectrum I cut my arrows to my desired length then I add my footers I personally hate a lot of arrow over hang I cut mine and as soon as it touches my rest I know I’m at full draw it acts like a built in clicker for me I have about 1” over hang and been doing it so long ain’t gonna change now LOL

 

[kbetts]

I've only ever used 1/4" long pieces of aluminum as footing. The inserts are far longer. Unless you're using footing that is passing the length of the insert.....the shaft is already stuffed and not flexing anyway. Where it has helped me is preventing an insert from being driven into the carbon shaft if you hit something solid.

 

[Heydeerman]

I have used footings to repair broken arrows. I had a box of broken carbons and scored a dozen 2117’s and a couple rainy days and I turned that box of busted carbons into a box of stump shooters.

One of the busted carbons became the sacrificial arrow used to get the rest to 30” bop. I cut all the busted ends and squared em up. Trimmed the collar off the inserts and glued them in. Cut a piece from the sacrifice to get 30” then cut a piece of 2117 and inch longer. I also put a half inch footing on the nock end of the arrows. Put that all together with epoxy and turned a bunch of junk arrows into shootable arrows. I use them for stump shooting since they are all slightly different in weight.