[Bender]

in reply to: Riser shelf design question #18338

Not only should the shelf be radiused but the sight window should be also. Whether the shelf and riser have been contoured this way or if you do it by applying something like a toothpick doesn’t seem to matter. You just simply need to have that single clearly defined pressure point. You will achieve greater forgiveness if both the high point on the shelf and on the sight window coincide with each other and they are located above the throat of the grip. (Assuming a contoured grip.)

The single defined pressure point assists in initiating the oscillations of going through paradox in the arrow with no “funny stuff” happening. This is hard enough without throwing in weird arrow flight to boot.

I have no actual empirical testing to support this. HOWEVER, I have seen the results of others attempting to shoot flat shelves and sight windows. Really bad arrow flight for one thing. And the “evidence” shows up as interesting wear patterns in whatever they may be using as shelf material. You’ll see 2 or more wear points along the shelf and sight window. The arrows seem to be either be striking the shelf and riser multiple times during launch, or upon release they are not always being pressed against the riser in the same place on every shot.

I have seen some who accidentally created a “work around” by running extremely high or extremely low nock points. This gets the arrow positioned on the shelf when at draw such that the arrow launches from either the back edge or belly edge of the shelf, basically inadvertently creating that single defined pressure point. Such an arrangement is still very much less than optimal though in that it makes the bow more likely to still randomly screw with arrow flight due to spurious bow torque that the shooter may accidentally impart to the riser.

[Bender]

in reply to: a duh moment… #33697

In just simple shooting I’m kinda on the fence if kneeling is more or less accurate. That is probably because when hunting when it is called for its still broken ground, or brush or whatever and so I’m still out of position in reference to good repeatable form. So its kinda hard to come to a real conclusion on the matter. However last year I did hit on something that undeniably improved my accuracy for target shooting.

It was at Rancho Neblina and we were on a string of targets along a bare ridge top. It was insanely windy in gusts. By kneeling down I pulled more of my body out of the wind and no longer felt the wind shoving me around or trying to blow the arrow off the shelf. Sure once launched, the arrow is going to do whatever its going to do. But by getting down out of the wind I became a more stable launch platform. Sure people looked at me like I was nuts, as it “appeared” that there was no good reason to kneel down. No brush or anything to get through. But I cleaned that string while others could barely get a shot off much less actually hit anything.

So as for hunting, we develop good form and execution, and practice that. And when we get that down, we work on trying to prepare for when things aren’t optimal and practice to learn just how out of form we can get and still have a good shot and what being out of form does to our effective range and accuracy. So I imagine that someday it will be a windy day and knowing to make the effort to be down and out of the wind will pay off. So although I figured it out while target shooting, maybe someday there will be a carry over.

[Bender]

in reply to: Twisted one up #44498

This IS very interesting!

So out of curiousity does anybody have any idea on what sort of lifetime a yucca bowstring might have?

Also how fat does such a string have to be in order to have the necessary strength to handle something like a 50# longbow?

[Bender]

in reply to: Cock feather? #44476

What draw weight are you actually pulling on those bows? I too suspect a tuning/spine issue.

Cock feather in or out technically should not matter. On a relatively narrow shelf cock feather in can allow you run a lower nock point while keeping the bottom hen feather from running into the shelf. The lower nock point can give you a longer point on and effective range.

If shooting cock feather in has the cock feather running into the riser and thereby shoving the nock end of the arrow to the side, you definitely have a tuning issue. It is NOT simulating a narrower shelf or anything like that.

[Bender]

in reply to: Turbulators #23525

Now this is interesting. Long story how it came about, but I got to have a conversation with a guy that is into model aircraft. He applied turbulators to his T-45 jet model aircraft. At first he didn’t have them, but then later did apply them. He simply placed them in the same place and orientation as they are on the real jet, but to scale of course. Sure enough, just like on the real ones, he got a slightly slower stall speed, that is the wings maintained lift and stability at slower speeds and/or greater angles of attack. The effect DID scale, AND produced a measurable result.

No, spin is not strictly “necessary” for stabilization. But I also know I want all the help I can get. 🙂

[Bender]

in reply to: Turbulators #22918

An arrow stabilizes with both drag AND spin. Out of curiousity, any idea what a turbulator does to spin?

[Bender]

in reply to: Turbulators #21921

Yes the whole purpose is of course to create turbulence. Its what you DO with that turbulence that matters. So I guess that by proper placement one could create a net INCREASE in drag as in Dr. Ashby’s explanation, OR one could create a net DECREASE in drag, such as when they are used in aircraft.

[Bender]

in reply to: Turbulators #21770

This is odd.

From my reading concerning turbulators and aerodynamics the turbulator actually reduces drag. Although surface friction goes up from the turbulent airflow, it is more than offset by reduction in overall drag because that turbulent airflow delays separation of the boundary layer airflow from the surface.

If I recall correctly O.L. Adcock was experimenting with turbulators to assist in making some of his flight archery records.

The problem with them is that in order to achieve optimum results they can’t just be placed where ever you want.

Here’s some additional reading on them:

http://en.wikipedia.org/wiki/Turbulator

and:

http://www.standardcirrus.org/Turbulators.php

[Bender]

in reply to: Best way to tune for wood arrows? #21745

Oh and Wapiti Archery makes a very good product.

Here’s a link to them:

http://www.wapitiarchery.com/index.php?cid=17

[Bender]

in reply to: Best way to tune for wood arrows? #21744

Whut Wesbrock sed!

Here is a link to a good tuning protocol for tuning woodies to be shot off the shelf:

http://veraxservice.net/arch/tuning.htm

[Bender]

in reply to: Pont On #61625

Very much what Moebow is saying there.

If shooting split finger, go to 3 under. If that’s not enough, go to a higher anchor as well. For example if your anchor has your index finger somewhere in the neighborhood of the corner of your mouth, move up so get your middle finger up there. This will not only give you a closer point on, but will do more to reduce the size of your gaps for distances closer than point on.

[Bender]

in reply to: Grip vs form #61482

Whut Wesbock sed.

Whut ausjim sed.

And as to Steve Graf’s comment, it makes no sense to me that a set up would shoot accurately, then as time passes, accuracy would deteriorate.

[Bender]

in reply to: Our Own Worst Enemy #61880

Actually whoever is doing that is technically NOT a “legal” hunter here in California (I’m in Northern California also) Wanton waste is illegal and a form of poaching. Realistically odds are against DFG catching whoever is doing this, but you should still take the first step and report it. Heck even if all that happens is some increased patrols in your area for a while, it will help serve to drive the poachers out.

[Bender]

in reply to: Sitka spruce and EFOC, failed experiment #40716

Have you considered bamboo?

[Bender]

in reply to: Washer Weights? #49269

Smithhammer wrote: I would focus on weight up front. Adding weight to the rear has no penetration advantage that I can think of, and would probably only complicate tuning.

Yeah.

Basically.

Sure you can make tuning changes with weight at the rear. But just because you CAN do something doesn’t always mean that you SHOULD.

[Author]

Posts