Half a croissant, on a plate, with a sign in front of it saying '50c'
h a l f b a k e r y
Assume a hemispherical cow.

idea: add, search, annotate, link, view, overview, recent, by name, random

meta: news, help, about, links, report a problem

account: browse anonymously, or get an account and write.



Rifled bow

  (+5, -4)
(+5, -4)
  [vote for,

This bow features a rifled hole just above the hand hold, to be used with a spiral shafted arrow to increase in flight stability.
simonj, Oct 18 2010

Spiral broadheads http://www.broadheads.co.za/features.html
spins from the front not from the back, according to this outrageously badly designed web site. [pocmloc, Oct 18 2010]

All about bow sights http://www.huntersf...-bow-sight-help.htm
for [MB] [pocmloc, Oct 18 2010]

About three-quarters of the way down the page... http://www.indiamar...59152/products.html
"Spiral cone" is a starting place for the arrowhead [normzone, Oct 20 2010]


       in't that what the fletches do ?
FlyingToaster, Oct 18 2010

       what spin the arrow? I don't think so
simonj, Oct 18 2010

       [+] \but you might want to look up something called "Archer's Paradox" involving arrow flex when it leaves the bow.
FlyingToaster, Oct 18 2010

       Uh, [simonj] - fletches can and do spin the arrow for stability. There are several ways to fletch an arrow, the main ones being straight, offset, and helical. Both offset and helical fletching cause the arrow to spin. The correct term would be roll-stabilisation, as the spin ratio isn't high enough to provide ballistic stability on it's own.   

       So most arrows are "rifled".   

       Archer's paradox is less relevant when using a compound bow (by far the more popular type of bow these days), due to centreshot, overspining and linear nock travel available in modern compounds. [simonj] didn't specify either way, and given the misinformation regarding fletching not spinning the arrow, I'd hazard a guess that [simonj] wouldn't know the difference.
Custardguts, Oct 18 2010

       Most arrows I have seen have straight fletchings, but some have spiral ones. I suppose the spinning caused by air resistance on the fletchings is less immediate than that caused by rifling, so any bending of the arrow as it leaves the bow will be relatively unaffected.
pocmloc, Oct 18 2010

       [simonj] Get someone to shoot you with each of the two types of arrows, then show us which does most damage. I don't approve of killing animals for "sport".   

       If it's for competition reasons ie Olympic Archery, then it's ok, even though it won't work, but the thought behind it is good.
xenzag, Oct 18 2010

       I like it. It might not suit every situation, but lack of fletches would decrease resistance which might increase range and/or decrease deflection from lateral wind.   

       You'll probably need a rotating piece at the end of the arrow so that when the arrow is pushed by the wire the arrow can freely rotate.   

       What's with all the bad vibes around here? <looks in the direction of xenzag and Custardguts>
xaviergisz, Oct 18 2010

       //the prey can't simply yank them out with their teeth or hands.//   

       Or hands? What counts as "prey" in your neck of the woods?
MaxwellBuchanan, Oct 18 2010

       Lack of fletching on an arrow turns it into a stick that yaws all over the place. Straight fletches are not particularly accurate.   

       If you want to actually hit your targets then you'll need to attach them in either offset or helical pattern. There are specialised jigs that are used to arrange fletching attachment at either 120 degree or 90 degree settings, each with exactly the same curvature.   

       Most archers spend a lot on their bow and little on their arrows, with disappointing results. In fact, the bow merely imparts velocity to the arrow... which needs to be a precision instrument if you want good results.   

       [21Q] is right, if you are using hunting arrows. However, target piles (points) would fit through the rifling proposed, as would sprung wire barbs. The problems would start when this device stripped off the fletches, resulting in misses and no way of stabilising the flight of the arrows. Bad idea, sorry.
infidel, Oct 18 2010

       [21Q]//widely regarded as the most effective for both hunting and combat//   

       Where exactly are bows and arrows used in combat? (Extending [Max]'s question, really. I want to avoid that neck of the woods.)   

       [-] for all the reasons given here. Fletching is still necessary and does the trick.
Boomershine, Oct 18 2010

       Would rifle-curved arrowheads contribute in some manner to this? It seems to me that spinning a flat blade head would have a different aerodymanic than a spiraled head.
normzone, Oct 18 2010

       [NZ] see link.
pocmloc, Oct 18 2010

       If you spun the archer, then no modifications to the bow or fletchery would be needed.
MaxwellBuchanan, Oct 18 2010

       From an article on fletching: "Each fletching should sit across the shaft a small amount to encourage the arrow to spin during flight (like a bullet), enabling it to fly straighter."
ldischler, Oct 18 2010

       I looked at [poc]'s link. I have to say, it has somewhat dispelled my image of the bowsman as being a simple but skilled backwoodsman living in harmony with nature.   

       I didn't look for laser telescopic bow-sights, but I'll be amazed if they don't exist.
MaxwellBuchanan, Oct 18 2010

       // laser telescopic bow-sights//   

       Used on crossbows. Normal bows don't rreally need them, as initial velocities are only 300fps or so, making it necessary to aim high for trajectory at any distance beyond 20 metres or so.
infidel, Oct 18 2010

       A brief look turns up laser bow sights but not telescopic ones... yet. [infidel], calibrating for drop and windage seems to be part of the challenge with using such contraptions.
pocmloc, Oct 18 2010

       guy guys guys! Where in my idea did I say I was doing away with fletches??
simonj, Oct 19 2010

       //Where in my idea did I say I was doing away with fletches??//   

       I got it from the phrase "rifled hole". Maybe add something along the lines of: "grooves/channels in the rifled hole would also be needed to allow the fletches of the arrow to move through".   

       I also think that a rifled hole will resist the movement of the arrow and possibly damage the arrow. Perhaps use rollers or bearings to sit in the spiral groove of the arrow to impart the relative rotation instead.
xaviergisz, Oct 19 2010

       I get the feeling that maybe a wider hole was meant to spin fletches rather than shaft. (+) for circulatorially linear thinking.   

       Actually, there is a type of telescopic sight available for bows.   

       It consists of a special lens that goes into the "peep" sight, and a second lens that goes into the sight attached to the riser. Kind of like a telescopic sight for a rifle but with no tube. No lasers, I'm afraid. Although there are both holographic red-dot sights, and projected laser sights as well. Just not combined that I know of.   

       Thing is, the telescopic version is not really used for hunting at all, but pretty much exclusively for some competitions (90 yard I beleive).   

       searching for a link now.
Custardguts, Oct 19 2010

       As a person who used to do a certain amount of re-enactment combat archery, it's not that fletchings are banned, but that they have to be fully an inch wide and 4 inches long or so. The idea being to slow the arrow down as it flies, so its terminal velocity is fairly slow. And the heads are not broadheads as usually understood, but rubber pads, with a circular cross-section end perhaps 1cm across. I remember the flat tip and the low speed of the arrows did make them a bit unstable in flight, and I did make a few with slightly offset fletchings, which spun as they flew and were more stable. On the other hand accuracy with these things was non-existent, one’s main aim was either to shoot flat and low to keep the arrows below eye-level, or lob them high so they rained down on the opposing forces.
pocmloc, Oct 20 2010

pocmloc, Oct 20 2010

       Here's the arrowhead format I suggest (link).
normzone, Oct 20 2010

       Why not use flu-flu arrows? They slow down very rapidly. Great for shooting birds and things that are running away.
infidel, Oct 20 2010


back: main index

business  computer  culture  fashion  food  halfbakery  home  other  product  public  science  sport  vehicle