[Ed Ashby]

in reply to: A heavy arrow that shoots flatter than a lighter arrow! #29755

So far no upper limit of arrow FOC has been found in the testing. The initial Ultra-EFOC (above 30%) are in the 2008 Updates, Parts 1 and 2, and there will be more in the next couple of 2008 testing updates. Results have been so impressive that I’m working towards developing some arrows in the 35% FOC range to test.

EFOC and even Ultra-EFOC are nothing new. I think use ‘moderns’ are just now rediscovering things some of the so-called ‘primative’ bowhunters have know for no telling how long. Check out the information on the Contemporary and Pre-WWII arrows of the Papus New Guinea natives! That article is in the library here.

Ed

[Ed Ashby]

in reply to: A heavy arrow that shoots flatter than a lighter arrow! #29265

Because this is a subject not well understood the following is a follow-up posting I made in reply to a question about how this can be. How does it not defy the Law of gravity.

“Nope, the law of gravity is being well enforced. As you’ll remember from grade school science, the pull of gravity is a constant, not dependent on the weight (mass) of the object. The Gravitational Constant is 32.174 feet/second/second at sea level. A falling body drops at this rate, regardless of its mass.

(1) A higher mass arrow absorbs more of a bow’s stored energy, and will carry higher kinetic energy than a lighter arrow from the same bow.

(2) If more of the arrow’s energy is applied to the arrow’s forward motion then the arrow will travel farther before it drops to the ground. A more efficient arrow design does exactly that; it conserves energy otherwise wasted on ‘non-productive work”, such as recovering from paradox and/or stabilizing arrow flight.

(3) A heavier arrow which derives greater energy from the bow and which also is of a design that makes more efficient use of whatever energy it derived from the bow can have an equal or shorter travel time across a given distance; ergo, gravity has an equal or lesser time to act upon the arrow and the drop at that distance will be equal or less.

As previously noted, several compound shooters who approached me at the ATA reported that they were getting equal or less drop at 20, 30 and 40 yards with a heavier arrow having EFOC than with a lighter arrow at low FOC (and in one case the shooter reported that he had tested to 60 yards, with the same results). The aggregate of reported results indicated that an EFOC arrow in the 24%-25% range shot to the same point of impact as a low FOC (in the 5% to 6% range) that was 150 to 175 grains lighter. This is congruous with the results I’ve had with equally tuned, equal mass/profile arrows; the equal mass, higher EFOC arrows shoot flatter (drop less) than the lower FOC arrows. This can only occur when the flight time is less. Since I was testing with equal mass arrows, equally well tuned, the bow derived force would be equal. For the flight time to be less the EFOC arrow has to be using its bow-derived arrow force more productively than the lower FOC arrow. This additional ‘productive arrow force’ can equally well be applied to pushing a somewhat heavier arrow fast enough to result in a ‘total flight time’ equal to that of the lighter arrow, resulting in equal arrow drop.

Now those compound shooters are generally working with more ‘potential bow force’ than most of us traditional shooters. That means a higher potential ‘useful force’ gain (from the same amount of increase in arrow efficiency), but the effect would be the same for a traditional bow, but to a somewhat lesser degree – dependant only on the amount of available force (at equal arrow efficiency).

It’s all about total flight time. Ask any competition 1000 yard rifleman which .30 caliber bullet shoots flatter (has less drop) at 1000 yards, the 200 grain Match King or the 180 grain Match King, when fired from any of the .300 Magnum cartridges commonly used in 1000 yard competition. It’s the 200 grain bullet, even though it starts out well over 200 fps slower than the 180 grain version. Why? Because it makes more efficient use of the energy it carries. Indeed, beyond 600 yards it will be traveling faster than the 180 grain bullet. The net result is a shorter total travel time to reach the 1000 yard target, giving a sorter time for gravity to pull on the bullet, which results in a lesser amount of bullet drop. Bullets are a far more efficient aerodynamic design than an arrow, which also means that the potential for gains in efficiency are far greater for the arrow, percentage wise.

Hope this helps clear up the gravity question,
Ed”

[Ed Ashby]

in reply to: A heavy arrow that shoots flatter than a lighter arrow! #29208

My pleasure Jason,

Just to save other folks the need to go back and forth, here’s the reply.

“In the simple demonstration arrrow used the dynamic spine on ALL the shots would be grossly over-spined. The propulsion system was a short section of modest strength bunge cord, drawn less than 10 inches. The shaft was a 20” section of dowel rod. The mass weight of the sliding weight is small. None of the shots represented a ‘tuned vs. untunes’ setup. All were ‘untuned’. It was a demonstration of the effect EFOC has on the flight characteristics of even a poorly tuned arrow setup.

I have, however, used matching arrows (same total mass and external profile, varying only in degree of FOC), equally well tuned, from the same bow and achieved the same results – the higher FOC shoots measurably (and significantly) flatter than the lower FOC arrow. To do so the higher FOC arrow has to be making better use of the force derived from the bow. This has been a 100% occurrance when testing with such matching setups.

Conversely, I have yet to see an equally well tuned lower FOC arrow that can totally recover from paradox as quickly (with the smaller fletching) as an arrow of higher FOC. That means that more of the arrow’s force is being loss to arrow flex. These results are not based on conjecture, but on repeated actual testing, from several different types of bows.

With big traditional broadheads (like the 190 Grizzly), Wesley Mulkey is getting total stability and can consistently hit 1″ dots at forty yards using a 2″ A&A pattern 3-fletch on a 28% FOC arrow setup. At lower FOC he can’t do that, even with considerabley more fletching and regardless of the tuning. That’s from actual testing too. Why does it happen? Because of the inate stability of a higher FOC projectile in flight. (Wesley is a three time Georgia 3-D champion, and by far the most accurate shooter I personally know.)

Talking with the folks at Win Win, most all of the South Korean FITA shooters are using well upwards of 19% FOC … and they’re the ones ‘taking the gold’.

Just as I told everyone at the seminar, there’s no trick or no magic. When we’re finished, feel free to come up and try it for yourself.

Hope that helps clarify,
Ed”

[Ed Ashby]

in reply to: In a few days … #28816

Dave,

They offered to fly me … but I had a lot to carry and didn’t see how I could endure both getting through an airport AND making the flight without any place to stop and rest. The van has a makeshift bed in the back – of which I made good use! Besides, I did enjoy just being able to get out and about for a change.

I hear Ron is planning to get some of the new, full thickness Grizzly’s unbeveked and offer them beveled and sharpened in both right and left bevel. Todd said he had received the first mock-up steel versions of the heavy, single-bevel STOS. Still no word on when they will be available.

Patrick,

Yes, there should be a video available. The folks from Alaska bowhunting Supply videoed the whole presentation … but I doubt they could get the entire flight of the EFOC demonstration arrows in the frame, since the impact was back of the camera!:lol:

Ed

[Ed Ashby]

in reply to: Help With Some Comparisons on EFOC? #48976

Very worthy project Steve. With enough different setups it could give some insights into reasonable starting point setups for different bow typesa and weights. I’ll have to dig some out.

Ed

[Ed Ashby]

in reply to: 2-Blade Broadhead and Angle of Impact #48000

Partick, with bone it’s not a much of a ‘grain’ thing. Bones don’t really have a ‘grain’ in the sense we think of wood as having a grain. Though there is a directional cellular orientation for some of the bone-matrix in some bones, such as the long bones of the legs, most bone lacks any pronounced directional orientation.

Bone cells interlock to a degree not seen in wood. When we speak of splitting bone we are speaking of spreading the bone apart to such a degree that we directionally stress the interlocking cell martix to the extent that a linear fracture is created. That’s why it’s rare to ever see a split that runs the length of a bone, like the full-length splits you get in wood when splitting kindling or firewood. With bone it’s more likely that a chip or chunk of bone will be broken away.

The bone’s interlocking structure but somewhat brittle nature is also why a rotating single-bevel BH generally makes a ‘hole’ when it penetrates the scapular flat, rather than creating a split; and why double-bevel BH’s punch such neat ‘profile’ holes in the scapular flat. To get a split through the scapular flat generally requires that the BH’s impact be down in the heavier portion of the scapula, near the head, and that the split initated there be in a direction that takes it through the area of the flat.

Broadhead orientation to the ‘long or short’ dimention of the bone has shown no difference in the bone-splitting tendency for any of the broadheads tested. The orientation of the broadhead to the long or short dimention of the bone does, however, make a difference in the direction of any split generated. Unlike wood, bone can be split in any direction. As far as splitting bones, what becomes important in the BH’s design is its ability to creat a directional spreading force sufficient to over-stress the bone matrix, creating a fracture. No BH design does that as well as the single-bevel single blade.

Hope that answered clearly enough to be understandable.

Ed

[Ed Ashby]

in reply to: hog hunting ranches. #47035

I’ll second 7th Age. Curtis is not only a great guide, he’s a bowhunter’s bowhunter! It’s a win-win.

Ed

[Ed Ashby]

in reply to: Ashby on sharpening — posted! #47029

All’s fair, Ron … I just stole it back for my files, lables and all!:D

Excellent explination.

Ed

[Ed Ashby]

in reply to: When and why do you replace your glove? #45987

I’m with Snuffy; gloves with reinforced finger stalls. I use each until I totally wear it out, to the point it can’t be used any longer! I’m more comfortable with a glove that I’m totally accustoned to. Few things screw my shooting up as badly as having to break in a brand spanking new glove. I always keep a couple of ‘new gloves’ on hand that have already been thououghly ‘broken in’, just in case I have to swap to a ‘new glove’ at a time where it really matters.

Ed

[Ed Ashby]

in reply to: Ashby on sharpening — posted! #45980

I located a couple. Here you go Patrick.

The burr is the wire edge that develops along the cutting edge once the bevel has been uniformly worked down to produce a thin edge.

Correct, careful removel of the burr, followed by honing and stropping results in a thin, smooth edge that is trult sharp.

Were the photos enough help?

Ed

[Ed Ashby]

in reply to: Ashby on sharpening — posted! #45930

SB, if you’ve got a good photo of an edge burr, could you post it for Patrick? I’ve looked through what I have here with me, and I have no ‘burr picture’ to post.

You’ll have to get Ron to demonstrate his limp noodle sharpening technique – a video perhaps!:lol::lol::lol:

Thank you,

Ed

[Ed Ashby]

in reply to: Upgrade to Ashby setup needs advice #44710

Johnny2, :D:D:D

I’m really pleased to say that you’ve already had some really, really good advice put forth. If your’re looking for EFOC there’s no doubt that you will need to look towards lighter weight (GPI) shafts.

Steve is correct that it’s virtually impossible to give a ‘cook book’ arrow setup for any bow and shooter. There are just too many variables involved. That’s where the bare shaft tuning comes in.

You are very wise to wait until the off-season. Arrow development and tuning takes time and, until you’ve done a few, you should go slowly and carefully, double checking every result before making a change. Using the off-season for arrow development gives you really good incentive to stay actively involved with your hunting setup AND you hunting mindset … and it teaches you a whole bunch about how arrows work too (I know that I’m still learning). As you build and test, that’s were it becomes easier to help with specific suggestions, relative to what you are finding as you test and tune.

If you look back in the Updates you’ll find a little bit about the testing with the lighter weight Grizzly BH’s. IN COMPARISON to the 160 and 190 grain versions, the ligher ones bend relatively easy. But don’t mis-read that; they are every bit as tough as most any of what I’d consider the ‘standard’ traditional BH’s.

Ed

[Ed Ashby]

in reply to: Zwickey No Mercy #42565

Needless to say, I’ve been a bit out of touch of late, but it’s my understanding that the left-bevel Grizzly became available a couple of months ago. I’m sure someone will on the forum know for certain.

Ed

[Ed Ashby]

in reply to: Elephant with a bow #42546

BV,

If your PH is the ‘right sort’ (and he had better be if your after elephant with a bow) you’re shot will be at very close range; probably well less than 20 yards. It’s relativel easy to get close to elephant … but it’s a lot harder to put distance between youself and them!

Even with the rifle hunters we wouldn’t let them shoot at elephant beyond 25 yards. It’s not that hard to get close, and you want your placement to be good. Along those lines, we had one, forever-nameless client who had a 25 yard shot, from a rest against a tree, on a standing elephant that was in the clear, nothing but grass from the rifle’s muzzle to the elephant. He didn’t cut a single hair! Elephants can do strange things to folks sometimes. Just stay focused on shot placement and forget all else … it helps control the emotions. Save the gitters for when it’s all over. When bowhunting the big, dangerous game it’s just as much mental ability as physical skills.

Ed

[Ed Ashby]

in reply to: Opinions and advice on arrow setup #42516

Rock, the Grizzly Stiks were designed from the ground up for one thing, hunting the bigger game. That means designed for the heavier broadheads too. I think you’ll find them among the easiest shafts to tune, just be sure to start with the shaft appropriate for your bow weight, draw length and the BH weight range you decode to use, then follow the directions. If you’re uncertain as to which specific shaft to start with for your bow, draw length and BH, just give Ed Schilef a call. I’ve never met Ed, but he seems very knowledgable of his product and is very, very helpful.

With a heavy head on a Grizzly Stik your arrow will end up somewhere in the EFOC range. If you want Ultra-EFOC (without well over a thousand grains of mass) then you’ll need to work something up starting with a lighter weight shaft. For what it’s worth, for carbon shafts that are not reinforced with an Internal Footing, the Grizzly Stik has the lowest damage rate of any I’ve tested. That might be a major consideration if your going to be ‘remote’ for a while.

Ed

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