Author Topic: Flight Arrows  (Read 42518 times)

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Offline DC

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Flight Arrows
« on: October 10, 2020, 06:31:39 pm »
I've decided to start this thread to track my making of flight arrows. This has been a sticky point for me and maybe if I write down what I'm doing people that know better can stop me before I waste a lot of time. I made two old growth Western Hemlock arrows a while back and they flew OK but I never got a chance to test them for distance. They were 28" long and spined at 50#. They were heavy compared to the weights I hear about at about 350 grains. I took them out to the backyard this morning and shot them at 10yds. They are fletched. They hit the target straight but I could see that they were nock right mid flight so I sanded one of them down. Tested it again and it looked better so I sanded more and this time it flew straight all the way to the target. I moved back to 15 yds and it was fine there. I measured the spine and it was 35#. There is no tip weight. Now it weighs 290 grains, much better. I thought I would try an Ocean Spray arrow in hopes of getting the same weight with a smaller diameter. I got it down to 43# spine and it was getting so skinny that the pith was starting to show at the ends(barrelled) and it still weighed 429 grains. I decided to assemble an arrow with 11" of OS in the middle and 7" and 10" of Hemlock front and back. I "V" jointed it together. This afternoon I sanded it down to 38#spine and barrelled it. It weighed 300 grains. The diameter was the same as the 290 gr Hemlock so I don't think it was worth the effort. It flew very well though so maybe it was recovering better. I decided to see how fast it was. I got 220fps but the arrow broke when it hit the target. So, don't test flight arrows on the shooting machine. I'll just assume that anything below 300gr is faster than anything above 300. Might not go as far but I haven't really got to that point yet.
And that's where I'm at. I think I learned some things but I'm a bit confused as to why the OS arrow didn't do better. How thin do you think I could make front and back if I drilled and filled the pith? Even if I did get it down to 35# spine I think it would still be way heavier than the Hemlock. OS is rather extreme so maybe I should try something more in the .7-.8 SG range?

Offline mmattockx

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Re: Flight Arrows
« Reply #1 on: October 10, 2020, 08:35:44 pm »
They were 28" long and spined at 50#.

Excuse a dumb question. I understand how modern composite arrows are spined, but exactly how does one define a 50# spine? What weight of bow the arrow will work for also involves the arrow length and tip weight, so it seems inaccurate to me to define a spine rating by bow weight?


It flew very well though so maybe it was recovering better.

The Easton X10 arrow is used by a lot of high level Olympic competitors because it is barrel shaped and the rear part of the shaft is spined more softly than the rest of the arrow shaft. This makes it more forgiving of bad shots by the archer, leading to higher scores. If your composite arrow shaft was also less stiff in the back portion that would explain it recovering better off the string.


I got 220fps but the arrow broke when it hit the target. So, don't test flight arrows on the shooting machine.

How do competitors test their arrows without breaking them? Only flight shoot them in an open field or use a backstop of loose straw or what?


Mark

Offline willie

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Re: Flight Arrows
« Reply #2 on: October 10, 2020, 09:28:00 pm »
Mark
http://www.primitivearcher.com/smf/index.php?topic=57378.0



Quote
so I sanded one of them down. Tested it again and it looked better so I sanded more and this time it flew straight all the way to the target. I moved back to 15 yds and it was fine there. I measured the spine and it was 35#. There is no tip weight. Now it weighs 290 grains,
Don, did you reduce the spine by sanding at the center third? before or after any barrelling?

in a nutshell, if you want to reduce spine, remove materiel in the center third, if you want to remove mass, reduce the outer thirds.

that said, if you barrel a parallel shaft with a known spine, it will static test less when you get done barreling, but the dynamic spine may not be reduced as much as the static test would indicate. Typically, the static testing charts assumes a parallel shaft.

you can certainly use static testing on barreled shafts for your own estimation purposes.

bownarra

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Re: Flight Arrows
« Reply #3 on: October 11, 2020, 01:27:42 am »
You should be going a lot thinner on the front end. :)
Read this - http://www.turkishculture.org/lifestyles/turkish-culture-portal/turkish-flight-arrows-554.htm
Try making some shafts that copy the dimensions.
In Saracen Archery there is a short section about a flight arrows made with 3? different materials. Strong dense center section and lighter ends.
I think that stuff about the X10's softer rear section is marketing :) Have you seen the price of those suckers! I'd rather make my own haha.

Offline mmattockx

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Re: Flight Arrows
« Reply #4 on: October 11, 2020, 09:58:01 am »
http://www.primitivearcher.com/smf/index.php?topic=57378.0

Thanks for that. So it appears the ATA # reading is arbitrary and you still need to figure out what spine you need once you have arrow length and tip weight factored in, which makes sense to me.


I think that stuff about the X10's softer rear section is marketing :) Have you seen the price of those suckers! I'd rather make my own haha.

It is very possible it is marketing hype, but that is what I have heard non-sponsored archers say about them. They are crushingly expensive. If I shot so well that I needed that level of arrow I would probably be sponsored and not concerned about the cost, but fortunately I suck so I can get by with cheap arrows and not know the difference.


Mark

Offline DC

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Re: Flight Arrows
« Reply #5 on: October 11, 2020, 11:31:45 am »
How do competitors test their arrows without breaking them? Only flight shoot them in an open field or use a backstop of loose straw or what?
Mark

I'm assuming so. Once you find the approximate spine so the arrow(and you) will survive the launch the rest seems to be aerodynamic so you need the long flight anyway. And the arrow that broke did survive being shot into a conventional target at 8-10 yards a half dozen times. The target bag in my shop is just too close at 7'. It's a burlap bag filled with plastic bags and old blankets that is free to swing from the ceiling. At Willie's suggestion I'm going to change the blankets for more plastic bags(the recycle bin is full of them) and that will make it lighter.

Offline DC

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Re: Flight Arrows
« Reply #6 on: October 11, 2020, 11:32:58 am »
Mark
http://www.primitivearcher.com/smf/index.php?topic=57378.0



Quote
so I sanded one of them down. Tested it again and it looked better so I sanded more and this time it flew straight all the way to the target. I moved back to 15 yds and it was fine there. I measured the spine and it was 35#. There is no tip weight. Now it weighs 290 grains,
Don, did you reduce the spine by sanding at the center third? before or after any barrelling?

in a nutshell, if you want to reduce spine, remove materiel in the center third, if you want to remove mass, reduce the outer thirds.

that said, if you barrel a parallel shaft with a known spine, it will static test less when you get done barreling, but the dynamic spine may not be reduced as much as the static test would indicate. Typically, the static testing charts assumes a parallel shaft.

you can certainly use static testing on barreled shafts for your own estimation purposes.

Yes :D

Offline DC

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Re: Flight Arrows
« Reply #7 on: October 11, 2020, 11:39:38 am »
You should be going a lot thinner on the front end. :)
Read this - http://www.turkishculture.org/lifestyles/turkish-culture-portal/turkish-flight-arrows-554.htm
Try making some shafts that copy the dimensions.
In Saracen Archery there is a short section about a flight arrows made with 3? different materials. Strong dense center section and lighter ends.
I think that stuff about the X10's softer rear section is marketing :) Have you seen the price of those suckers! I'd rather make my own haha.

I just found and bookmarked that site yesterday. I have a piece of aircraft Spruce ready to go. The measurements given are for a 25" arrow. If I want a 28" arrow should I just multiply each dimension by 1.12(28 divided by 25). I'm concerned that will make the spine and arrow too heavy. I could reduce it from there though but that may mess up the aerodynamics.
For no particular reason I was pleased with the performance of the three piece arrow. I will try it again. Maybe with something a little lighter in the middle. Do you have a link to the info about them? One of the neat things about this sport is thinking you've come up with something new and finding out it was tried hundreds of years ago. I really think that other than new materials, everything has been tried.
« Last Edit: October 11, 2020, 11:47:01 am by DC »

Offline willie

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Re: Flight Arrows
« Reply #8 on: October 11, 2020, 12:48:43 pm »
I really think that other than new materials, everything has been tried.

but old ways of doing things escape us.

I am curious about different ways to test flight arrows for their needed qualities. Is a three point deflection test as is commonly used for most arrows, the best way to evaluate flight arrows? Does anyone use a cantilever bend test on half the arrow? or a  column buckling (compression) or other kind of test ?

https://pgmagirlscouts.files.wordpress.com/2012/10/saracen_archery.pdf

Offline DC

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Re: Flight Arrows
« Reply #9 on: October 11, 2020, 02:12:51 pm »
The column buckling seems to me to be the test that would most duplicate the situation but for a couple of things. If the arrow is even slightly bend it's going to buckle that way. Also the ends of the arrow would have to be precisely square for the test. If pointed, the point would have to be dead center. We used to very slightly angle the bottom of the masts on our model sailboats to induce a forward bend when we tightened the stays. The masts were 5' long and 1/2" dia and just knocking one side off a bit with a file would cause the mast to bend forward. If you wanted the mast to stay straight it had to be turned on a lathe. It was a very sensitive part of setting up a boat.

Offline DC

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Re: Flight Arrows
« Reply #10 on: October 11, 2020, 02:15:42 pm »
Saracen Arrows on a girl guide site????

Offline DC

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Re: Flight Arrows
« Reply #11 on: October 11, 2020, 02:38:38 pm »
It finally downloaded, boy that was slow, but it looks like a very cool pdf. Thank you.

Offline willie

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Re: Flight Arrows
« Reply #12 on: October 11, 2020, 04:17:29 pm »
Quote
The column buckling seems to me to be the test that would most duplicate the situation but for a couple of things. If the arrow is even slightly bend it's going to buckle that way.

its going to bend out of the bow any way, so maybe knowing which way would be informative.  I have been making replicas of NA atlatl darts. A compression test is commonly used by dartmakers to determine "spine". I have one unusual dart example that can only be placed in the atlatl/spear-thrower one way, and it is elliptical in cross section, so it is well understood which way it is going to flex first.

Offline DC

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Re: Flight Arrows
« Reply #13 on: October 11, 2020, 04:36:38 pm »
Yes it would be informative but can you trust a piece of wood to keep the same bend, especially after you've straightened it. But I guess that's going to happen anyway. I've been thinking a pipe clamp would work. One of those long ones with the screw thing on the end. I think they're called a pipe clamp ::) ::)

PS yes the pipe clamp worked. One arrow popped through the same every time and the other seemed to kinda prefer one area but not consistently. Bothe the arrows had the nock already cut---  wrong :D

Offline willie

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Re: Flight Arrows
« Reply #14 on: October 11, 2020, 05:51:23 pm »
so what I find with the darts is when you compress the dart on a scale, the force builds until the shaft springs sideways. at that point, more force causes more deflection, but the scale sort of stabilizes. hard to describe.