dimensions, sizes, spine of an arrow

Luko (We already have a Dusan from Slovakia) Welcome to our forum. You are like a scientist with all your calculations! These calculations tend to drive me crazy also. Why don't you just make several different arrows and give them a try? This will need to happen anyway.

Might I suggest making your own nocks for a more authentic look?

jack farrell wrote:

Luko (We already have a Dusan from Slovakia) Welcome to our forum. You are like a scientist with all your calculations! These calculations tend to drive me crazy also. Why don't you just make several different arrows and give them a try? This will need to happen anyway.

Might I suggest making your own nocks for a more authentic look?

Hi Jack,
my name is Dusan, lukostrelec is a nick which means "archer" in slovak :-)

Well yes, these calculations. While shooting with less powerful bows in the past, I just experimented with various types of shafts material, feathers, points, lengths, weights...until finally I had become tired of it. It was very difficult to distinguish the best design just by experimenting. Moreover, one can adapt to his/her own non-correct arrows and learn to shoot perfectly with them :-) - and this fact, in particular, drove me crazy :-)

So I have dig deeper into the physics and mathematics of the bows and arrows and finally learned something. Now I now (I believe) that my arrows are of the exact weight/length/fletching in respect to the physics of my bow so I can focus on perfecting my own shooting technique.

....nocks - well yes, on some arrows I cut just a dent for the string to fit, but it is still not so comfortable.

Du?an,
Your calculations look good, but there are several variables that might throw them out. Firstly, the type and quality of your release affects the spine of the arrow you will need to use. Secondly, natural materials like bamboo have enough variability that 16 grain differences will not have much effect. Thirdly, traditional bows with out centre shot windows need a more flexible arrow than a modern bow.

Your logic is good. Increasing the weight of the head decreases the spine. Shortening the arrow increases the spine. But Jack's suggestion that you might need to experiment is true. You can start from where your calculations lead you and adjust from there.

If you shoot three fingered, you may need a slightly softer arrow. If you use a thumb draw, you may need a slightly stiffer arrow.

I don't believe that Our Ancestors did all that math in the past (after all "spine" thing is modern invention) Yet they knew what to do to make a missile as accurate and forgiving as possible. If you look at the majority of old arrows you'll clearly see that they all share common features such as barreled shaft, long, low profile feathers, well carved nock, often made out of stronger than shaft material. For some reason this is commonly overlooked today, and many are happy with cylindrical shafts and plastic nocks. Tapering itself will make an arrow more forgiving and suitable for wide range of bow weights as long as its stiff enough. Self nocks are easy do make. Look at the Koreans, they don't bother with all those calculations, they take an advantage of shafts natural taper making small adjustments to make arrows closely matched in weight.

If you shoot three fingered, you may need a slightly softer arrow. If you use a thumb draw, you may need a slightly stiffer arrow.

Bede,
this I really did not know about. I shoot with three fingers with a tab, as it is impossible for my fingers not to hurt when drawing 75# :-) Could you please elaborate more on the subject?

Daniel,
yes, you are right, I too doubt that the ancients did any of the mathematics I dig into now :-) While I visited one Huron museum in Canada, I was surprised how well their arrows had been made, but too I was surprised they were not straight at all :-) And we know from history that American Indians were masters in archery.
Ancients did train themselves in archery from very early childhood and they learned with their whole bodies intuitively how an arrow would fly just upon touching it (at least I imagine it was so). I tend to this intuitive archery too, however to perfect my intuitive technique I decided first to calibrate my arrows perfectly :-)

I suppose the important thing is to separate spine from stiffness. Stiffness is the resistance to static bending of a piece of material and can be measured by a spine tester. Spine is the dynamic flexural quality of a complete arrow which is influenced by several things.

• 1. The stiffness of the shaft.
  2. The distribution of material. A barrelled arrow is a perfect example of varying the diameter while still retaining the stiffness in proportion to the flexing of the arrow. It also reduces the weight for an arrow in comparison to its stiffness.
  3. The mass projecting from the bow at full draw, normally the arrowhead. It can be different with different forms of traditional arrow.
  4. The ratio of the mass of the arrowhead to the mass of the shaft.

In answer to Daniel on some points: cylindrical shafts became popular when machine made shafts became cheaper than hand made ones. Plastic nocks were easier to put on centred than cutting self nocks. Plastic nocks worked efficiently with centre-shot bows. Making shafts myself sometimes, it is just as easy with a hand made shaft to make it barrelled as to make it cylindrical. People interested in traditional skills are sometimes getting there in small steps. They should be encouraged.

There is a place for formulae and physics in traditional archery. They provide a way for compensating for the fact that traditional masters are hard to find. They give a description of archery equipment that often attracts people from outside with valuable skills that can help us make better, more traditional equipment. Without metallurgists' interest, would we know how to make Damascus steel? Just look at books written fifty years ago about traditional archery and compare them with Adam's book on Ottoman bows.

The not-straight arrows in museums have two sources: old wood warps and not all arrows in museums were made for use. I travelled through the Mid-West and parts of the West with Dr Grayson a few years ago and saw many museums and discussed the exhibits with the curators. The methods by which equipment was placed in the museums and its history often explain its poor condition. It's not their fault. Money and space often restrict what can be done to conserve old wooden objects. If they come into the museum in a poor condition, they may still be accepted because they are the only samples the museum can get.

The vast majority of American Indian arrows were made from natural shoots rather than split from a log section. These arrows will hardly ever stay completely straight for very long. It was traditional to restraighten them all the day before they were to be used.

It always amazes me to see barreled shafts with expanded nocks from diverse cultures who could not have had any influence on eachother.

Like phragmites arrows also.

"cylindrical shafts became popular when machine made shafts became cheaper than hand made ones. Plastic nocks were easier to put on centred than cutting self nocks. Plastic nocks worked efficiently with centre-shot bows. Making shafts myself sometimes, it is just as easy with a hand made shaft to make it barrelled as to make it cylindrical. People interested in traditional skills are sometimes getting there in small steps. They should be encouraged"

Agree, but it the same time I can not help it but say that some of traditional arrow makers these days are hardly making anything at all, it's basically simple parts assembling operation. Machine made shaft, molded plastic nock, machine made point, pre cut feathers, some glue, some paint...
Majority of shafts used in horseback archery aren't even wood.
I know, I know - convenience, repeatabillty, durability, increased performance. Well I'd always ask modern alloy shafts user when was the last time you try well made, matched barreled wood arrows? How far behind carbons are they and in what aspects? Reasonable ones, without slicing and dicing analysis.

"There is a place for formulae and physics in traditional archery. They provide a way for compensating for the fact that traditional masters are hard to find. They give a description of archery equipment that often attracts people from outside with valuable skills that can help us make better, more traditional equipment. Without metallurgists' interest, would we know how to make Damascus steel? Just look at books written fifty years ago about traditional archery and compare them with Adam's book on Ottoman bows"

Absolutely, but how many composite bows had been made in pre McEwan, pre Smith, pre Novotny, pre Karpowicz era? Old Korean Masters are in my humble understanding not necessary scientists in theory of math & physics but they have a deep understanding of the materials. I really like what Adam said in his book about mechanics of natural materials being to complex to be easy predicted in theory. So as much as I can appreciate formulas and recipes given us by calculations - these are only start point and by all means can not replace knowledge acquired by experimentation. I think these Guys are more than Craftsmen - they're Artists!

Bede,
thanks for you part related to stiffness and spine. I have been distinguishing these two parameters as static spine (=stiffness) and dynamic spine. BTW thank you to put exact diacritic mark over s in my name (Du?an) - how did you know that? :-)

Jack,
yes, you are right, one should count the age of the material found in museums. I have attached the Iroquoise arrows picture I have spoken about. Contrary to those I have visited Egyptian museum in Cairo 2 years before and Tutanchamun's arrows are in much better condition, although they are almost 3000 years older. But the fact is that the different climate could play the role and the different material too, as you have pointed out.

Daniel,
yes, that is why I tend to use natural materials so - in any situation - I would be able to manufacture hunting/war arrow/bow equipment myself. This I can say about the arrows, and longbow; not about composite bows (I have produced many longbows, but these are piece of cake comparing to composite ones :-) )
I have experimented with many wood material, from which I have prepared shafts and straighten them just roughly, not perfectly, to imitate harsh conditions of our ancestor (yes, you are smiling :-) )
I have shaped the feathers in the same manner too, sometimes to the point they were hurting my hands. So yes, one can experiment with making own points from bones, shells - but not! from iron as I would need to have a hearth which only specialized workmen had among our ancient ancestors :-) One can further experiment with making fletching, nocks....
I accustomed myself to every such an arrow and I knew where it would tend to fly because of its shape....but, as I have mentioned earlier, I had become tired of it. Now I am combining my knowledge - i.e. mathematics, physics, knowledge of materials - together with traditional archery ways.....for me, to practice and learn to perfectly shoot, as I like it, I use nocks and points commercially made... :-) and experiment with my own primitive equipment during special "sessions".

let's go back to spine etc.
It is quite strange for me that although I scientifically calculated the dynamic spine of my arrows (79#) and I have carefully manufactured them accordingly, still I experience them flying slightly to the right of aimed target. I am right hand archer. This indicates to me that the dynamic spine of the finished arrows is still too little for the combination "my bow + me". And the calculations gives 79# which should be ok for my 75#/27'' omg :-)

I have experimented later with arrows which I have manufactured from beech shafts. I have bought them in a regular shop with wooden goods :-) so I do not know their spine, stiffness, nothing :-) I could check their weight, but my digital (sic!) weight corrupted just few days before :) so I just smiled and kept on experiments.

As expected, they are harder than bamboo, all of them tend to end slightly to the left of the target. First I had manufactured them at 31.5'' (so to keep general size) however their weight seemed to be too heavy, although they flew pretty straight. Finally I have cut them to 28'', to have them of the exact length as my chinese-bamboo arrows. They are ending still in the left side of the target (while I should aim little bit higher). However their flight is somehow disappointing: when leaving the bow they are waving horizontally from side to side till a 150gn point drags their flight to be more smooth.



further experimenting....

Regards,
lukostrelec Du?an

What if you tried out an arrow which worked well but did not fit into your formula?

Du?an,
Your name has some history and that is where I came across it, plus we have another on the forum. Not having a special keyboard driver, I use an add-on for Open Office which allows the easy insertion of specific characters and also supplies a keyboard macro to automate their construction.

I have found traditionally prepared bamboo arrows to be much stiffer than the comparably made wooden arrows, but untreated bamboo can be softer. The arrows in your picture have a curve that would be consistent with them being stored for years standing up against a wall in the museum.

Egyptian arrows are often found tied in bundles or lying flat, which combined with the atmosphere may explain part of their surviving straightness.

Wood varies in its stiffness because it is not uniform. Each piece can be individual though statistically a large group with average out. The turks were aware of different properties depending on how far up the trunk it was cut, the prevailing wind and how much sun it received when growing.

Jack,
you hit the point :-) Yes, the best target results come from using a cedar shaft, however I do not like it, as it is not durable and brakes often. It would not break if I would just practice using some regular straw target.... However I usually practice in nature, in steppe places (which are several around my home), or in a forest, where I choose some visible dry leaf to hit from whatever distance. Under such conditions it is no wonder that I hit some stone, or a piece of hard wood hidden under the surface and cedar arrows brake (at a point).
That is why I tend to use bamboo and beech shafts, which do not break - especially arrows from beech, they just bounce back when hitting a stone :-)

Bede,
yes, your explanation of straightness between the two ancient arrows we discussed, is pretty reasonable.
The location of a produced shaft along a cut trunk of a tree is very good point. This gives me another reason why not to use cedar shafts, as they are produced from quite long trees, and I seriously doubt that commercial manufacturers take care of their exact position in the sense to sell bundles from a very defined place of a cut tree :-) .... at least I did not come along any such an offer throughout the internet.
Using your reasoning bamboo shafts are the best! When a manufacturer cut bamboo he is cutting it from one location (I guess). Later on, when he/she is spinning it, shafts with uniform spine would be very probably of a same age and/or place of a whole bamboo stick.

Thank you!

Du?an

I heard something new today about this perfect arrow problem. Apparently there is a machine at a nearby archery store. They take your bow and put it on a shooting machine. You give them different groups of arrows. The machine shoots one arrow at a time into a target. The size of the groupings is noted. The arrows with the closest grouping is the most ideal of those shot.

This is called, here, a Hooter Shooter. Ha! (Maybe means shooting from an outdoor bathroom? or such)

Where do I get information about barreling a parallel wood shaft? I am most interested in making Manchu style wood shaft. The only online reference I find is about English war arrows: http://www.cheshirearcher.co.uk/makingawarbowarr.html

Jack,
:-) :-) :-) hooter shooter :-)
no, I will not go in front of this machine :-)

Manchu arrows of some types had barrelling that was quite developed, but in others the thinning was concentrated in only two areas. One was the shaftment, from in front of the feathers to just before the nock.

The other was from about a hands breadth or two up to the point.

The first can be done by making a groove with a file in front of the nock and shaving the shaft down to the bottom of the groove. This can be done with a knife and finished off by scraping with the edge of the knife.

The second is easier. You drill a hole for the tang in the end of the shaft and shave the end down to the edge of the hole. After the arrowhead is inserted and glued in place, you build up sinew to reduce the taper and support the head and then cover the sinew with bark or waterproof paper.

Regarding profiling wooden shafts, you can mark your shafts with a pencil or stain it for reference, as mentioned in various how-to's, you can also use a gauge with holes of different diameter, but you can also do very well just feeling and judging the dimensions by eye.

As to the hand tools either a very sharp and finely set small hand plane and/or a hinged and grooved sanding block (I'll try to post a picture later on).
I sometimes use a spokeshave too.
A very good tool, if sharpened properly, would be the 'bowyers edge' made and sold by Dean Torges, this ingenious scraper allows you to ignore the direction of the grain in wood and produces very consistent results, whereas a plane can tear the wood when planing against the grain.

You can also taper shafts on a belt sander by rolling them in your hands or stick them in a viced drill while you sand them with sandpaper, for a more consistent effect with a sanding block (a fast spinning shaft can catch the paper, trapping your fingers along).