The perfect arrow

[Jay Campbell JD]

For an adhesive alternative to epoxy, I can vouch for gorilla glue as a great product for these kinds of carbon arrow laminations. It expands to fill all gaps, remains flexible, holds in temperature extremes, and is extremely tough. Also, in closed in spaces like arrow shafts, some air-dry products can't cure properly. Gorilla glue doesn't require air. - Jay Campbell, JD

[Tilzbow]

I built an arrow similar to this method because I've got an extremely long draw and I can't find a readily available shaft stiff enough to tune out of my 60# bow.

I shoot a full legth 32 3/4" 340 spine arrow with standard aluminum insert and 125 grain point from my 50# at 32" draw A&H ACS CX and Centaur bows.

I just made up a batch of four with the following ingredients:

- Axis 300 black shaft, full length

- Beman Carbon Flash shaft 3" internal footing behind the insert

- Easton 2018 external footing 2.5" long

- Standard Aluminum Insert. Might try the new 50/75 grain Easton brass insert or a 100 grain brass insert in my next four arrows if I need more weight to tune.

- Golf Works Epoxy 24 hour cure/flexible

The gluing method is similar to described in this thread.

With the HIT insert the 3" internal carbon footing is just under 5" into the arrow shaft and I will make the IF longer or shorter depending on how the arrow bareshaft tunes with my desired weight of point. The 2.5" external footing covers the entire insert and 1/2" of the internal footing so the weak point is moved back nearly 5" from the point.

I believe an external footing is a must with the HIT insert shafts since the area between the insert and the point is the weakest spot on the arrow in my experience.

I also "foot" the nock end with a 3/8" long piece of the 2018 shaft. This prevents nock damaged to the nock end of the shaft.

After reading this thread I hope the Beman Carbon Flash IF is a little flexible so the front of the arrow will bend a little bit. I might try the tapered hardwood IF method described in this thread if my method doesn't work out.

This arrow weighs 620 grains with a 175 grain head. I haven't shot the combination but I'm hoping for good results. I'll post pics on this thread with an update in a few days after I have some time to test it.

[James Wrenn]

Sorry but I just have to ask...      

.What do you guys shoot with arrows that makes them need all these footings? I understand wanting a durable arrow but you guys must be bounceing arrows off tanks or something.  :D

[O.L. Adcock]

James, I've had arrows break behind the heads on "elbow" shots and you can not shoot an arrow in this country without hitting a rock. You can say "don't hit elbows" or shoulder blades but if it hasn't happened to you yet, it will!   ....O.L.

[James Wrenn]

OL I guess my girly weight bows probably don't have enough punch to break my arrows anyway.    I might make up an arrow for the toughman shoots like you guys however.I have crippled a few on the steel targets before and I think the ones some of you are making might be great for that. thanks

[O.L. Adcock]

O.L. promised I'd post some cutaway photos of the IF's, so here they are. My apologies for the delay, but my back is still not 100% functional - still slows me down a tad!

Photo 1 shows the full IF in place, back of the brass insert. Note that the cutaway shown does NOT go to the center-line of the shaft. When the shaft is flexed to show how the IF works, everything tends to break lose from the shaft's wall if the cutaway is made to the center-line.

 

Photo 2 is a closup of the IF/insert junction. They are epoxied together, but keep the glue joint very thin. In testing, the thin junction worked better than a thicker junction.

 

Photo 3; The red arrow shows the 'glue dam wedge' that is created nack of the IF's parallel (glue attached) section. As I explained earlier, this is acomplished by applying epoxy to the shaft's inner wall (to the depth of the IF's glue attached segment) prior to inserting the IF. This is an important step in obtaining maximum direct-impact strength. (The glue-attachment section of the IF is also coated with epoxy prior to insertion in the shaft.) Insertion of the IF into the shaft pushes a ring of the excess epoxy on the shaft's inner wall up into the shaft. By using a very slow-cure epoxy, and storing the assembled shaft vertically until the epoxy is fully cured, the epoxy forms the glue ring; immediately back of the IF's parallel segment.

Even though the cutaway is not to the shaft's center line, note clearance between the IF's tapered section and the shaft's inner wall (green arrow).

 


Photo 4 shows the terminal end of the IF.

 

Photos 5 and 6 show the shaft flexed against the terminal end of the IF. Remember that the IF also has a graduated dgree of flexion, "like a good salmon rod". with the cutaway shaft I can't achieve enough shaft pressure against the IF to make the IF flex, something easily done when the shaft is intact.

 

 

Ed

[Douglas DuRant]

I am impressed again with the attention to detail and testing. Thanks for so freely sharing the info!

[TomMcDonald]

Nice.

[Kingwouldbe]

First off, both of you are nutts (Doc. & OL) and I love ya for it, did you guys blow up the garage with your chemistry sets as a kid lol.

Just when I think I got something good cooked up, you two go and raise the bar again, you two are great.

Now the shafts I am using are vary small internally, I have used 7"x 1/4" steel cable for EFOC with amazing results, it fits nice and tight.

so, for these shafts, what could I use to do this IF thing on them.

Thanks

[redant 60/65]

Dave, Dave you have to much time on your hands, time to go back to work.      :cool:

[Featherbuster]

thats preety cool

[Kingwouldbe]

Got another question, what if you put say 5" of aluminum shaft over the front of a carbon shaft and you put 4 cuts down the aluminum footing like a + sign, so it had some give, say 2 cuts 1" and 2 cuts 2" long.

Does this sound to crazy.

[O.L. Adcock]

King, I was doing that internal with brass tubes. It worked but was a PIA!  

The tiny shafts, bet they aren't smaller then some of my flight arrows, less then .125"ID so sure, it'll work. Carbon rod would probably work best. Do a search for Aerospace Composite Products, (ACP)...They have carbon rod and tubes of many sizes. Another trick, glue 1"-1 1/2" of carbon rod in the back of a carbon shaft, taper it on a disk sander just like a wood arrow and glue nocks on. Works great and lighter then the aluminum nock inserts....O.L.

[Tilzbow]

OL,

At the start of this thread you wrote:

3" is the minimum for the parallel front section. This will keep from shoving the insert/footing back into the shaft on solid frontal hits. More then 3" could be used and more then 7" total length, just depends on if you want to increase spine and or get more weight up front.

Did you find through your testing that 3" of parallel front section had little to no effect on the dynamic spine?

The reason I ask is because on an earlier post I added on this thread I discussed trying a similar method with an Axis shaft and a 3" carbon IF. This arrow shoots very similar to the same arrow without the IF. I'm thinking I need to lenghten the IF to 5" and give that a try because I'm getting a 3" left tear with both shafts when paper tuning. When I get closer via via paper tuning with different shaft/IF combo's I'll bare shaft tune but paper tuning is the best I can do right now given the short days, my work schedule and the fact I'm not home during daylight hours and can't shoot outside.

[Tilzbow]

BTW - Once I'm close on the correct parallel section length I'm going to try to taper the carbon IF similar to the wood dowel as described at the start of this thread. I'm not able to find a wood dowel that's small enough for the Axis and I thought I was stuck with the Beman Carbon Flash shaft for an IF but after seeing OL's post about the ACP composites company I found some better alternatives. I might also try cutting the last four inches of the IF in fourths, too, as previously mentioned a couple posts up.

...Or change shafts to a Gold Tip or standard Easton and use your method. That could prove cheaper and easier!

[O.L. Adcock]

Scott, 3" with 7 1/2" total length is as far as I've gone so far and it doesn't seem to change the spine much. Logic dictates it has to make it stiffer but the added weight may off set it. Carbon would be more then double the weight but stiffer also. It's hard to take well tuned "normal" arrows then do this and draw any conclusions, just too many things changed. Got some hunter super carbons that static spine 60# and only weigh 200 grains for a 29" shaft. I bet they'll come in at 25% but only weigh about 525gr. Perfect for the lighter bows....O.L.

[Tilzbow]

OL,

The only thing I can figure is the front 3" to 4" of the arrow doesn't flex much anyway so that plus the weight may result in the effective spine staying about the same. I love the idea you and the doc developed and trying to get it to work on an Axis shaft is sorta fun.

I ordered some .196 diameter carbon tubes from ACP composites tonight. These are slightly bigger than the Carbon Flash shafts which are .1815 and slightly smaller than the brass Axis insert at .202 but with some heavy epoxy they should work okay. I'm thinking the carbon rods are a bit too heavy and would be difficult to taper (cutting in fourths might work) plus the closest size is .186 which might be a little loose but I ordered one of those just in case I want to experiment.

I'm going to try to cut the tubes to 9" in length and then cut the back 4" in fourths. That'll give me a 5" parallel section to stiffen spine and 4" of shock absorbing material. I hoping the 4" section cut in thirds will help absorb impact shock similar to your tapered shaft design. If I can get this arrow to tune I'll report back the results in a few weeks and hopefully I don't get lung cancer from all this carbon dust I'm going to produce!

[Str8Arrow]

O.L. thanks for all the great ideas.

I have a question on the oak dowels. Most that I've seen are poor quality and usually warped. Are you truing them up with the sanding, or have you just selected those that appear to be straight? Also, how snug should that first 3" fit?  Thanks,

[O.L. Adcock]

Str8, Yep, got to pick through them. I cut them to length then chuck them up in a drill press. I use a flat metal sanding plate called "Permagrit". They come in various grits and are tungsten carbide embedded on steel and last for tens of years under heavy use but sanding blocks with 50 grit or some rasps would work also.

I do the parallel section first using a cut off piece of shaft to check fit, then I flip it over and do the taper. I weigh them to find the lightest then touch up the heavier ones till they match. Takes about 45 minuets to do a dozen. Others may find faster or better ways. Perfect straighness isn't needed since it only comes into play thumping something hard.

Tilzbow, Sounds like that'll work!    Carbon is a little tougher to work with but not much. Just don't be shy with the sand paper or rasp, 36 grit is your friend!....O.L.

[lt-m-grow]

This is fun stuff.  And amazing.  If someone said make me an arrow shaft that can be shot into a solid steel plate and not break, I would have said impossible, especially with EFOC.  Wow.

So my question is, "where does all the impact energy get dissipated?"  The force on that arrow at impact is huge.  The wood must get hot.

You know an interesting thought is the IF is really the arrow and the "traditional" (funny using that word here) arrow shaft is just the launch or guidance vehicle - at least at impact.  Maybe that is why it doesn't break (as much).  

Thanks for sharing.