Bruce SmithhammerApril 1, 2015 at 3:40 pmPost count: 2514
I’ve been experimenting with a different arrow setup for the upcoming spring turkey/bear season, and I’m curious to get your input. I’ve been hesitant to bring this up here, as I know that some of this may be controversial, but let’s please keep it civil. I truly would like your honest feedback.
First, a little background – a friend of mine had been playing around with weight tubes in his arrow shafts to try and increase his arrow weight forward of center. It worked fairly well, but the tubes kept coming loose inside the shafts, which is a fairly common problem. He experimented with gluing some of the tubes in place inside the shaft, and that helped. But one day we were shooting together and we both kept noticing that one of his arrows was penetrating the target way more than the others…and that it was the same exact arrow every time. We kept scratching our heads, and couldn’t figure it out, since he was confident that all of his arrows weighed the same and were otherwise identical. Eventually, we discovered that the internal weight tube on this particular arrow had not only slipped loose inside the shaft, but had slid backward and lodged itself firmly in the aft end of the arrow.
This went against everything I knew (and just as importantly – everything I believed). But the proof was in the target – this arrow was consistently a couple inches deeper in the target than the others. Hard to argue with the real-world results that we were seeing, so we started playing around with this notion a little more, affixing various weights to the aft end of a variety of different arrows and getting similar results. Of course, these setups required that the nock height be adjusted a little bit to account for the weight imbalance of the arrow, but once that was done, they flew flat as a pancake and penetrated like a freight train. So far, we have only experimented with carbon and aluminum shafts, but I’m still hopeful there will be a way to get a similar effect with a wood shaft as well.
Not being physicists, the only thing we can figure that accounts for this is that the additional weight at the nock end of the arrow “pushes” the arrow deeper into the target upon impact. And because this additional weight is at the aft end of the arrow, it is essentially continuing to “push” the arrow deeper into the target even after the point has already penetrated. I hope that description makes sense?
I’ll hopefully be able to post some pics this afternoon with more details that will demonstrate the idea, but I’m curious – has anyone else found similar results?
Doc NockApril 1, 2015 at 4:01 pmPost count: 1150
Waay too complex for my feeble mind, Bruce…
I can make on OBSERVATION though…
Per your request, only making observations a nd not inciminating comments, but adding weight rear-ward STIFFENS spine…
Is there ANY chance that the arrows were not well tuned to start with given the weight tubes?
If not, and t hey were weak, they’d end up relying on the fletching to correct them… and would tend to do more paradoxing in flight, thus wasting imparted energy…
With the weight to the rear, effectively stiffening spine and then impacting deeper, it would seem (SEEM) to suggest the culprit is spine issue and not a challenge to EFOC.
BTW, back before we discussed EFOC, we all tried to “heavy-up” carbon light shafts,, cried for heavier shafts and got them from arrow makers.
NOW, Doc Ed andI chuckle cause we’re looking for LIGHTER GPI so we can load up the front and not end u p with rebar weight shafts!
I tried the weight tubes… the arrows took o n entirely different spine!!! They flew side ways and then took a hard left turn and burrowed under the sod to never be seen again. I then went with 2 strands of .095 weed eater line, which presented it’s own problems.
I gave away the weight tubes (minus one). Read on another site where several people had spine issues with weight tubes, others not!
Just thinking out loud to get your creative juices flowing!
Bruce SmithhammerApril 1, 2015 at 4:31 pmPost count: 2514
You bring up an important issue with effects on spine. I’ve had decent luck by simply going lighter on the point weight to compensate for the additional weight in the rear, and that seems to keep the spine within reasonable tolerances. But I think that if you were going to go to extreme aft weight, you’d need to bump up the spine for sure.
I’ve been racking my brain to come up with a better way to explain this whole thing, and I keep coming back to the common phrase used in EFOC conversations – that the additional weight in the front of the arrow creates an effect much like a “dart” that has weight forward. But if you actually take a close look at a dart, this analogy isn’t really accurate. A dart has a long, skinny needle in the front which is very lightweight (obviously). The actual weight of a dart is not in the front at all, but towards the middle or even toward the aft end of the dart. Take a typical dart, find the mid point, and see where the dart actually balances. If the EFOC argument were true, the dart’s balance point would be well forward of center, but I’ve never found a dart that demonstrates that at all, has anyone else? Instead, the EAOC model is more like what a dart truly is – very light in front, with significant weight behind it, pushing it along, and therefore creating better stability in flight and better penetration – just like a real dart.
I hope that helps.
Doc NockApril 1, 2015 at 4:54 pmPost count: 1150
Not to be contestual and perhaps this should be a PM/Email, but I think the point/point of a dart is not the “point” 😯
I’m not a dart aficionado, but ones I recall had skinny butts and big fat cigar shape…then a wire ‘point/point”. I took my reading of the same description as being the “SHAFT” of the dart to be tapered to the front like nock tapered arrows…???
But you raise a good issue.
Only “counter” i can add is that in my findings, a tiny bit of tail weight changes FOC a hell of a lot MORE then a more sizable addition to the front weight!
EX: by adding cap wraps (22+/- gr) off set my foc by a HUGE per cent wehre adding 25 gr. up front didn’t make a lot of difference. Also with a cap wrap, it made my arrows FLY stiff when they were weak prior!
I ended up spraying a cap wrap on my shafts to avoid that…
Did you bare shaft the shafts with the weight tubes up front?
When I bare shafted mine, using Troy’s guide to tuning EFOC, I was dead level nock and square on!
Then per his suggestion, I went back to 20-25 yards and shot those lovely level and nock proper shafts and oye! 😯 out about 15 yards, they did some squirrely stuff…still HIT straight on and straight level, but they did that “barrel roll” to MY EYE, which Troy says in slow motion is the arrow kicking… mine were tailing weak.
Only 3 out of the 12, which isn’t unusual for carbons of good mfg to have variance in a couple out of any given dozen.
On my 12 GT, I had 3 that needed a good spanking! I #’d them so I could track em, and shot and shot… same 3.
One took a saw cut width (1/16″), 2nd took 1/8″ cut and the third, a full 1/4″ cut to bring it in flight down range with the rest.
If I’d have quit at 10-15 yards, I’d never have known.
All just FWIW.
Carbon arrows I learned a long time ago behave according to some “dynamic spine” stuff, which I don’t understand…so I just started doing what I was told in the tuning guide, which was different from my non-efoc bare shaft planning method, using troy’s on Tuff Head site, and walla… I got good results…but I did EVERY thing he said, AS he said to do it and was amazed at what I would have MISSED had I tried to THINK my way thru.
Good luck. I’m going outside and play in the dirt!
Bruce SmithhammerApril 1, 2015 at 5:23 pmPost count: 2514
Thanks, Doc – you’ve added a lot of ‘food for thought’ to this conversation!
We did bareshaft the EAOC arrows, and they didn’t porpoise as much as I thought they would at all. But like I was saying above, I find that nock adjustment is really important – if you leave the nock at a typical height for a normal arrow that has weight forward of center, you will definitely get porpoising. However, raising the nock point significantly (we found that 1-1/2 to 2″ above normal produced the best results) seems to compensate for the tendency of the arrow to leave the shelf with the nock end low (due to the additional aft weight). As the EAOC arrow leaves the shelf, after being released from a much higher nock point, it essentially ‘lifts’ the nock end of the arrow after clearing the bow and then travels dead straight. But I can’t emphasize enough that this adjustment in nock point is critical to successful flight with this type of setup.
But thanks for all of your input – I’m hoping to get out this afternoon and experiment a little more, taking your feedback into consideration as I tweak this experiment.
More to come…
Bruce SmithhammerApril 1, 2015 at 7:17 pmPost count: 2514
eidsvolling wrote: What if you turned the arrow around and shot it back-assward? Wouldn’t that give you the best of both worlds?
Well, I know that sounds like a crazy idea, but I actually did try that as well. A few things that I found with this approach:
1) Since it was no longer an EAOC arrow, but the exact opposite, I had to re-adjust the nock or else I’d get a lot of nose-diving, even at close range. I know this “opposite of EAOC” approach can work as well, but I think it would be wise for me to save those experiments for another time, so that I don’t confuse my results.
2) Cutting a notch in the field point, in order to be able to place it on the string was problematic. I ended up splitting quite a few field points this way.
3) Plastic nocks aren’t durable enough for this ‘bass-ackward’ approach, in my limited experience so far. When they didn’t explode on impact, I would lose them in the target when I attempted to pull the arrow out. I’m thinking about approaching a few manufacturers with an idea for a new, much more durable nock for these kinds of setups. Fletching also seems to limit penetration.
I don’t expect this idea to gain a lot of acceptance, at least not yet. But I think it’s interesting to stretch the limits of what’s possible, and what has become clear to me is that a lot of it just comes down to properly tuning the arrow to the bow.
grumpyMemberApril 1, 2015 at 11:17 pmPost count: 962
As I recall, from my childhood, the expression is
Ass-backward. Not that it is a major point, but it was generally attributed to farmers. But I come from a rather obscure corner of the woods.
Generally when I have that many gory details, I keep them to myself. Once you have sorted it all out (assuming you don’t ass-backwards shoot yourself) let me know. If a physics major shows up it would be a great help (limited to high school physics here), but in all my years I have never met a physics major who was an archer, or fly fisherman. This could be telling us something….:roll:
David CoulterMemberApril 2, 2015 at 1:52 amPost count: 2270
Yep, bass-acward it is, trickled down from ass-bacward to be sure.
But we digress. In my way of thinking I’d join Mike. As long as you can keep that thing flying straight it might work great, but if the rear gets a chance it might want to become the lead. I know if I bump a twig with efoc it maintains itself. I would like to test the acward-bass model to see what happens.
Keep in mind, efoc is still heresy in some schools and has naysayers on this site, too. So before stones are cast, let’s look at the science.
Thanks for posting this idea, Smithhammer. Good luck with your experiments. I look forward to the results, whatever they may be. Peace, dwc
Stephen GrafModeratorApril 2, 2015 at 10:40 amPost count: 2371
Now that the joke has been revealed, I guess this piece of advice is past it’s due date…
I would have suggested that after you come to full draw and settle in for the shot, you release the bow instead of the arrow. The results of this improved method upon arrow penetration would be interesting 😀
I would like to say that within every joke, mistake, wrong turn, and even prejudice can lay a small kernel of truth… Here’s one:
I have found that EFOC arrows can fly well even if they are torturously under spined. These arrows will not penetrate as well as a correctly spined EFOC arrow.
I found this effect when I discovered that bare shafts can actually be “tuned” (fly straight) at two different lengths for the same point weight. It shows up in both carbon and wood shafts. I haven’t tried aluminum.
To see how it works, take a full length arrow shaft and start adding weight to it. Use the most weight you can up front. Then start dropping the weight until the shaft stops acting under spined and flies straight.
Now take another shaft and match it to the first and shoot it. Once you have verified that it flies the same as the first,
cut off a quarter inch and see what happens. What I have found is that likely as not, the arrow will begin to act weak again. Which is the opposite of what you would expect. You will then have to keep cutting the shaft until it flies straight again.
When you compare these two arrows side by side, the shorter one will be more forgiving and will penetrate the target deeper.
Doc NockApril 2, 2015 at 12:11 pmPost count: 1150
Since April Fools is over, Steve, let me say that is the most confounded thing I’ve read in a while, but I won’t doubt you!
You did say FLIES right…not impact according to a 1″ vertical line to help define weak or stiff as to where it hits… Yes?
Curious is right. There is so much about a simple ‘stick and string’ that as we explore and delve deeper, is so very CURIOUS!
Like Doc’s article on those New Guinea folks… they ended up with arrows nearly as long as a spear, but redesigned their bows to use metal heads! When you have to kill what you eat, I guess there is a LOT of motivation to try all angles. We’re just blessed with creative spirits to unlock what more than likely, native people of long ago in the bow/arrow evolution learned and forgot!
Charles EkModeratorApril 2, 2015 at 6:17 pmPost count: 563
Charles EkModeratorApril 2, 2015 at 11:00 pmPost count: 563
Webmother wrote: 8) Don’t make me regret this…
The video can stand for now, but it cannot start a “discussion” of political views, no matter how civil.
I shot my bow yesterday and thought today about how it went. 😉
Bruce SmithhammerApril 2, 2015 at 11:32 pmPost count: 2514
Just got in from shooting my bow in one of the most bone-chilling, nasty winds I can remember. And I’m sad to say I’ve walked away from the EAOC experiment. Alas, “Extreme Aft of Center” was a pipe dream…
I like the new avatar, Mom. 😉
Doc NockApril 3, 2015 at 12:09 amPost count: 1150
the family filter is in effect, but the kids know better!
Might not KNOW, better, but “know” in spite of trying to be coy, or spelling, or any other lame tricks parents try to use to get “questionable” words and thoughts past the young’uns! Amen!:lol:
Doc NockApril 3, 2015 at 2:38 amPost count: 1150
Hmmm…do I take Bruce seriously or is this another hoax???
I never had a clue, not till the sawed the field point to slip onto the string… and shoot backwards…
OK, dokey… yes, Bruce, that is a stall mat 4’x6′ and it’s heavy! lag bolted to the back side (NOT bass ackward) of 4×4 header, it took a John Deere bucket to get it up there so we could set it into the metal brackets and screw it down
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