1.) bluecat - 04/16/2014

Don't know if this is the correct use of the term spine, but every arrow has a heavier side based on the way the carbon fiber shaft is built. I've heard you can put your arrows in the bathtub after corking the raw shaft so it floats. The heavier side will end up on the bottom. I've never done this so can't attest to how well it works but it seems like it would.

I heard last night in a pro shop of someone (locally) who had built a gizmo that detects this without using water. The arrow rides on some ball bearings and a weight is applied to the shaft which then facilitates the shaft to rotate.

Seems like this would be pretty handy when building your arrows. Knowing where the heavier side is would help to eliminate time consuming nock tuning for each shaft. Once you've fletched your arrows and you find out that it flies better with the nock turned might the cock vane in a spot that might conflict with your rest set up.

So what the heck am I talking about anyway? Is there something out there that would achieve this? Has anyone achieved this using the bathtub method?

2.) bluecat - 04/16/2014

I did find this which explains it pretty well.

3.) Ventilator - 04/17/2014

You are correct on the bathtub theory and the gizmo being in existence. Steve Archery Arrows has one of those gizmos. Every set of arrows they build are made using this theory. Excellent thing to do for a bit more accuracy. Professional archers have done this for years. Ive gotten a couple dozen arrows from Steve. They are in Illinois. [url]www.stevearcheryarrows.com[/url]

4.) bluecat - 04/17/2014

I like that bathtub thing so well that maybe getting a gizmo isn't really all that necessary. Anywho, I've got a bunch of raw shafts for some arrows I will be building for the recurves we will be shooting. So I will have to get Mr. Bubble and see what I can do.


Now the question is...

So you find the spine of your arrow, does it make any difference how the spine is oriented when the arrow is sitting on the rest? I would think up or down would be best with maybe down the optimum. Since I shoot a dropaway like 99.999999999999999% of the people, my cock feather is straight up. So therefore the cock feather would be the exact opposite of the spine of the arrow.

5.) Ventilator - 04/17/2014

I believe the cock vane goes on the stiff spine of the arrow. orientation on the rest probably doesn't matter. Anyways, that's how Ive always done it. This would be spine up for me.

6.) bluecat - 04/17/2014

Thanks Vertislicer. Although it seems kinda meticulous, I think a few minutes of your time would be well worth the effort and probably eliminate discrepansies in accuracy between arrows.

7.) Swamp Fox - 04/17/2014

Arrows in the bathtub have always caused me problems...

8.) bluecat - 04/17/2014

[QUOTE=Swamp Fox;18880]Raw shafts in the bathtub have always caused me problems...[/QUOTE]

fify

9.) Ventilator - 04/17/2014

lol.

My good buddy Johnny H was doing this in the 80s when he was at the top of his game. Must be good for something.

10.) DParker - 04/17/2014

OK, I'll be the dummy who asks: Why does the orientation of the spine relative to the rest matter?

11.) bluecat - 04/17/2014

I didn't make that too clear. People generally mark the spine by placing the cock feather at that location. For a dropaway, you generally want the cock feather on the top. So if you want to have the cock feather mark the spine then your spine will on the top. It probably doesn't make a difference whether you have the spine on the top or bottom. It's just how you want to mark it in relation to your rest setup. Does that make sense?

12.) Ventilator - 04/17/2014

The idea is its supposed to let the arrow spin truer at the shot, if im not mistaken. Meaning if the vane is aligned with the stiff side of the arrow shaft.

13.) bluecat - 04/17/2014

I was just trying to get the arrow off the shelf without impacting the dropaway rest. As to the location of the spine on the rest, one would have to maybe see the effects of the different spine location upon initial thrust. I'm just guessing here but if the spine was top or bottom the oscillations might be more condusive to good flight as opposed to the arrow being flexed up and down on a spine that is stiffer on the side.

14.) bluecat - 04/17/2014

Who really nos all this stuff anyway.

15.) bluecat - 04/17/2014

For a recurve you want your cock vane pointing to the left (right-handed shooter). I would still want the spine on the top or the bottom.

16.) Ventilator - 04/17/2014

what is a recurve? ive heard rumors about something called a longbow too. :huh:

17.) DParker - 04/17/2014

[QUOTE=bluecat;18888]As to the location of the spine on the rest, one would have to maybe see the effects of the different spine location upon initial thrust. I'm just guessing here but if the spine was top or bottom the oscillations might be more condusive to good flight as opposed to the arrow being flexed up and down on a spine that is stiffer on the side.[/QUOTE]

I assumed it might be based on something like that. But....is there any evidence to support that hypothesis? Or is this just one of those "that's how people do it" sort of things? I mean, even if it does determine the orientation of the arrow's oscillations (and that idea seems rational to me), is having the oscillations impact flight vertically less undesirable than horizontal impacts, or some combination of the two?

18.) bluecat - 04/17/2014

The answer to your question is I don't know. :-) At the very least, all your arrows are starting off with the same set of parameters.


I'm basing this on the fact that people (not me) nock tune their arrows. Occasionally you'll have an arrow that doesn't behave like another. By turning the nock (adjusting the spine around) you can bring that arrow to group with the others. With that being said you have to make the leap of faith that spine was the factor.


It would be a great study for sure and probably fairly easy to perform.

You could have one blind group that doesn't know the spine of the arrow and moves the nocks until the arrows are hitting where they are supposed to. It would be interesting to see if the spines of all those arrows are all oriented the same after adjustment.

19.) bluecat - 04/18/2014

Found this which helps a little too.

[url]http://www.archerytalk.com/vb/showthread.php?t=1680390[/url]