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Sturgeon

Archery Thread

96 posts in this topic

In other news: I made my buddy a slingbow using a bow saw frame, thin nylon rope and exercise bands. It actually works pretty well, and may be the easiest bow build ever. Definitely an option for biding time while making a proper bow.

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For the triple-post: wooden bows are a pain for me because I live in a country where the commercial options are pine or meranti. Fibreglass bows are also a pain, because you need linear glass to make really useful bows and core materials are still an issue.

 

As far as making a self bow goes, it should be borne in mind that yew, osage, hickory and black locust are super-woods and that the D-shape profile of an English longbow is otherwise retarded. For people without access to good wood, your flatbows are going to be the easiest to make and your pyramid bows will provide the best performance. For people with access to tropical hardwoods, the circular cross-section bow becomes the best option due to it's light tips and even stress distribution.

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If you live in the US, then making yourself a red oak board bow is about as simple as it gets:

http://poorfolkbows.com/oak.htm

Hell, you don't even need fast flight or whatever for a string. Just something reasonably thin and non-stretchy. Tie bowline loops at each end and off you go.

For arrows; find straight dowel rods cut along the grain and use duct tape to make the flights. Pretty much any flat metal sheet can be used to make broadheads, and I tend to use rivets to make practice arrows heads.

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The last few centimetres of a metre-long projectile don't do much to change its penetration. Colour me amazed.

Also: a golden opportunity for testing stone arrowheads against small, yappy dogs was missed.

 

I don't know, I imagine it would change quite a bit if you switched the last few centimeters of an M829A3 rod with shredded newspaper and glue.

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I don't know, I imagine it would change quite a bit if you switched the last few centimeters of an M829A3 rod with shredded newspaper and glue.

We're talking at most 5% of the length of the projectile here. So long as you don't make something overtly designed to shed energy (like a rubber tip) your penetration will not be affected too much.

So yeah, replace the last 2.5cm of a 50cm long rod with a similar shape made from newspaper and glue. Call me back if dramatic changes in penetration take place.

 

Edited -  because I didn't maths correctly.

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*Scene cuts to Khande reenacting the William Tell feat with arrowheads made of newspaper, paste, old bubblegum...*

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If you live in the US, then making yourself a red oak board bow is about as simple as it gets:

http://poorfolkbows.com/oak.htm

Hell, you don't even need fast flight or whatever for a string. Just something reasonably thin and non-stretchy. Tie bowline loops at each end and off you go.

For arrows; find straight dowel rods cut along the grain and use duct tape to make the flights. Pretty much any flat metal sheet can be used to make broadheads, and I tend to use rivets to make practice arrows heads.

 

Or you could just drop fifty bucks on a PSE Snake and a few arrows, no woodworking required.

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And for those of us in an urban environment, a cheap and easy markmanship hobby is to take a pair of scissors to the bar and cut the cardboard coasters into the shapes of throwing stars.  Then, you can chuck them at the heads of the most annoying people in the establishment.  However,be sure to wear all black so that they automatically assume you are a ninja, then they will be too scared to try to kick your ass.  

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This relies way too much on your average bar patron knowing that the chubby guy in a black cotton jumpsuit is supposed to be a ninja...

:ph34r:

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This relies way too much on your average bar patron knowing that the chubby guy in a black cotton jumpsuit is supposed to be a ninja...

:ph34r:

That's why you do like famous actor Richard Harrison and wear a special ninja headband that says the word "ninja" right on it.

 

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LoooSeR likes this

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You can find some pretty faithful and functional recreations of period bows for reasonable prices and several reenactor supply sites/shops.  

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Okay, since I've finally found a moment to go to a decent lumberyard near my house (Silverton lol), I'm going to resurrect this thread.

 

I bought a bunch of bamboo floorboard and have a piece of raw bamboo left around from an old project, so I'm going to aim for a bamboo-backed floorboard design recurve. First, though, I'm going to do some experiments with the thing I do have a lot of: the bamboo floorboards.

 

Bow physics ends up becoming a pretty involved topic, so I'm just going to dumb a bunch of overlapping resources here and move on:

http://archery.berkeley.edu/wp-content/uploads/2011/08/Fundamentals-of-the-Design-of-Olympic-Recurve-Bows.pdf

http://www.surfchem.unifi.it/solid/bardi/archery/modelingbows/

http://margo.student.utwente.nl/sagi/artikel/mathmod/mat2.html

 

The experimental bow rough dimensions will be: 150cm long, 3cm max width and 2cm thickness. The plan is to glue on a 30cm floorboard riser (my boards are 180cm long), taper the width only at the last 30cm or so (down to a 5cm tip)  and tiller as needed thereafter. Once the tiller is sorted I will try to heat-bend the tips as agressively as possible and glue some fabric to the back to hold it together a bit more (no siyahs, no power lams). I have also had lots of problems in the past with point failures on the back, so I will probably add strapping as well. Finally, I'm keen to add string bridges when it's all done to centre the strings and give the whole thing a bit more snap.

 

I really don't like the look of modern centre-shot risers, and believe pretty strongly in working risers as a way to keep length down. I've also heard (and experienced) that bamboo takes a pretty agressive set if not reinforced. So I fully expect this bow to wind up with some deflex at the centre and a much less aggressive tip reflex once it's shot in.

Donward likes this

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So something I'm very proud of (read: have almost certainly posted about before) is that I thought up an easy way to determine energy storage in materials. Yes I know this has probably been done a thousand times before, but (1) I did it on my own and (2) the competition here isn't exactly sparkling.

 

So, essentially all you do is take the resilliance of the material and divide it by density to get the energy storage/kg of material. Remember to use yield strength rather than ultimate tensile strenghth, exhange modulus of rupture for materials under compression and you've got all the basics covered.

 

Here, then, are a bunch of materials and their energy storage potential (tensile):

  • 4340 steel - 807 J/kg
  • Nylon - 773 J/kg
  • PVC - 186 J/kg
  • HDPE - 424 J/kg
  • Red oak - 781 J/kg
  • e-glass (linear strand, epoxy) - 5500 J/kg
  • e-glass (ideal woven mat, epoxy) - 2765 J/kg
  • Yew - 880 J/kg
  • Balau - 519 J/kg
  • Bamboo - 583-836 J/kg
  • Hickory - 767 J/kg
  • Spruce pine - 495 J/kg
  • Horn (estimated) - 3970 J/kg
  • Black palm - 620 J/kg
  • Coconut palm - 427 J/kg
  • 1040 steel - 304 J/kg
  • Black wattle - 696 J/kg
  • Chop-strand glass in polyester (30% by weight) - 408J/kg
  • Rubber (natural rubber stretched to 500%) - 2596 J/kg
  • Muninga (kiaat) - 913J/kg
  • Rhodesian Teak - 471J/kg
  • Bubinga - 861 J/kg
  • Burmese teak - 586 J/kg
  • Sitka spruce - 510 J/kg
  • Sweet cherry - 843 J/kg
  • Mountain hemlock - 647 J/kg
  • Brazillian rosewood - 783 J/kg
  • Blue Ash - 733 J/kg
  • Live Oak - 583 J/kg
  • Hard maple - 668 J/kg
  • Paper birch - 537 J/kg
  • Lemonwood - 910 J/kg
  • Massaranduba (bulletwood) - 741 J/kg
  • European beech - 597 J/kg
  • European alder - 647 J/kg
  • Jelutong - 404 J/kg
  • African walnut - 715 J/kg
  • Merbau - 812 J/kg
  • Mansonia - 917 J/kg
  • African blackwood - 1001 J/kg
This pretty handily explains why yew, horn, hickory and tonkin bamboo get so much love for making bows, as well as why everyone uses linear-strand fibreglass when they feel like being serious. I have no explanation, however, for why there are so few steel and nylon bows out there.
 
Edit: Check out indian and persian steel bows though.
 
Even more woods:
  • Balsa - 345 J/kg
  • European Ash - 641 J/kg
  • Osage Orange - 831 J/kg
  • White Poplar - 539 J/kg
  • English walnut - 898 J/kg
  • Black locust - 807 J/kg
  • English elm - 525 J/kg

The calculations for wood fit very well with people's experiences, by the way: yew, hickory, walnut and osage orange are well known for being amazing bow woods. Ash is a wierd one, as almost everyone who has worked with it hates the stuff, while the people that don't make longbows out of it.

 

This also means that, as a lot of people have contended all along, the idea that low-density woods can be made to work in bows by simply increasing the width is a lie. This idea comes from the assumption that lower strength correlates with lower density, which as far as I can tell simply isn't the case. Bowyers still talk about about successful bows made of pine as these nigh-mythical beasts, and this is the reason why.

 

Edit 3:

 

Pines are bullshit (except maybe slash pine):

  • Western white pine - 481 J/kg
  • Slash pine - 704 J/kg
  • Longleaf pine - 561 J/kg
  • Spruce - 495 J/kg
  • Lodgepole pine - 489 J/kg
  • Jack pine - 501 J/kg
  • Red pine - 470 J/kg
Belesarius likes this

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To be fair, for many non-academic cultures, the line between superstition and science is basically nonexistent.

I mean, hell, you can even see this clearly in the US blue collar class.

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I'll put some specific examples below, but here is my general beef:

My view of superstitious behaviour, ritual etc. is pretty similar to my view on selection; in that most of it is neutral while the stuff that provides a concrete advantage rapidly gets adopted. Although people are perfectly capable of justifying things because 'we always did this' and 'the gods say so', it's amazing how fast the gods can change their minds when necessary.

The issue of a default assumption of backwards superstitious behaviour is that it doesn't even try to see why other people may do the things they do. Nor does it result in pointing the finger back at yourself to work out why you do things differently. You don't investigate, because you already have your answer. Instead you just go with the first seemingly plausible thing that pops into your head and call it a day.

This, ironically, is a lot closer to superstition than it is to science.

 

Edit - specific examples:

  • The profile of the 'paddle' bow in fig. 22 is really close to a holmegaard bow. The holmegaard bow form, in turn, has become something of a talisman for trad bow types because it provides superb speed and can be made from low-density woods. Ergo, if the researchers had stopped blathering about leaf-shapes and whatnot for a few minutes and actually tested an example, they may have been very suprised at its performance.
  • The spin-test for arrow straightness is neither a british invention nor a panacea. Rather, it is good for giving you a general idea that something is off, and requires real skill to move from that appreciation to determining the cause. Further, straightening by eye is perfectly okay for shooting at close distances (25m is still the norm for hunting wild pigs). Finally, I'd argue that the idea that arrows need to be perfectly straight to begin with is pretty much bullshit. They rely on drag for stabilization, after all, so even a fairly obviously bent one will end up flying more-or-less true. This has been confirmed by people who shoot hand-straightened arrows, which end up being almost wavy when viewed down the shaft.
  • The idea that the principle issue with a flatbow is the increased wind resistance against the limbs is hilarious. Although to be fair the authors have (almost) grasped the principle of making a bow wider rather than thicker to accomodate poor quality wood.
  • The idea of midribs and c-section bows being the result of trying to copy the form of leaves and such is ridiculous except as a just-so story. Bows don't care about your need to decorate and will simply fail if you fuck with them in an important fashion. My guess here is that theory regarding splitting a pithy stem is closer to the truth, or that the c-section is used to enhance stiffness of an otherwise rubbery wood.
  • Interesting to note: figure 34 depicts the same New Guinean bow that the article I posted earlier referred to. Here the authors did an actual study into the matter, and found that the bow had replaced the earlier black palm longbows used by those people for very good reasons. If only authors at the turn of the century, who had much richer material to work with, had been interesting in doing similar studies rather than vague ethnographic surveys.

Edit 2: compare and contrast

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