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Post by silverdragon on Oct 30, 2014 9:43:54 GMT
Have Mythbusters covered the cutting a rope by Bow shot idea?....
Couple of ideas...
Multiple ropes with weights on the end in the target area to start with, getting that accurate is time consuming, so getting more targets seams natural.
Use of different arrow heads... some were designed to part ring-mail, some to dig deep, were any made for the explicit reason of cutting?...
Can "Someone" come up with a swing rig to test different heads on a rope...
I am thinking of a swinging rig that would bring an arrow head at the end past a known point where a rope could be strung to prove concept of hit.
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Post by Cybermortis on Oct 30, 2014 10:47:35 GMT
No they haven't covered this, in fact I think they have only done three arrow myths, catch an arrow, penetration of wooden tipped arrows and splitting an arrow.
This idea has been posted before somewhere else, as I do recall mentioning having seen/heard something about there being a type of arrow head specifically designed to cut rope - although I'm questioning the reliability of what I remember. It was certainly covered in the history section entry about King Olaf, as there is the story in the Saga's about one archer cutting another archers bowstring with an arrow - although it seems that there are two slightly different translated versions, one of which just mentions breaking the bow rather than cutting the string.
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Post by the light works on Oct 30, 2014 15:11:51 GMT
I recall seeing both cutting a bowstring, and cutting a rope - and yes, there are allegations of arrowheads designed to cut ropes - it basically had a forked head that was sharpened inside the fork.  I would guess an airgun would be the best way to do preliminary tests. - a tube big enough for the arrow with either a sabot to drive the arrow directly, or a plunger to fire the arrow down the tube, and the rope held in clamps across the end. as for the king olaf story, I put it in the same category as I put the allegations that JFK's assassination was impossible: can you miss a man sized target on a boat? vs can you miss a mans sized target with two shots out of three in 5 seconds? |
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Post by Cybermortis on Oct 30, 2014 16:06:00 GMT
Higher end arrows are designed so that the tips screw off, allowing the same shaft to be used for target practice or hunting depending on which tip you decide to use. Rope-cutting tips are not, as far as I know, something that archery shops sell or anyone produces. So MB would either have to make their own or commission someone to make some for them.
Either way they might as well just use those tips on arrows from the start. Rather than messing around trying to convert an air gun so it can fire an arrow (or short stick with an arrow head).
Quicker and cheaper to just rent a bow (if they don't already own one) and make the arrow heads themselves.
This would probably work best as part of a number of 'arrow' related myths, maybe a segment with trick arrows - the TV show Arrow uses a fair number of trick arrows (hardly surprising given that the main character is DC's Green Arrow even if he isn't called that at this point). Maybe they could look at trying to duplicate some of those trick arrows from the show, some trick arrows (like the above) from the real world and some of the more outlandish trick arrows Green Arrow uses in the comics; The 'Boxing Glove' arrow turned up on Disco fairly often and I recall Stephen Amell mentioning them trying to work out how to make one for the show since the first season. It is possible that if they went with the Arrow TV series CW and DC might be more than happy to co-operate if A&J come up with a valid trick arrow or two they could then use on the show. After all M5 is now involved in R&D, and this does seem like the strange kind of challenge Jamie could get his teeth in and both guys would be well suited for.
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Post by WhutScreenName on Oct 30, 2014 19:12:19 GMT
Not to mention shooting the rope to save a hanging man (they did it with a gun, but not a bullet) like in Robin Hood etc..
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Post by the light works on Oct 31, 2014 0:15:28 GMT
the image I posted is a modern commercially made replica of a medieval rope cutter arrowhead...
and as for testing - I was thinking along the lines of a fitting for Jamie's pop gun - with the idea being that it guarantees you will hit the rope. thus , proof of concept, first - followed by real world trial.
and certainly, add more trick arrows - there are also whistle arrows mentioned. I forget what other special purpose arrows I have heard of.
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Post by Cybermortis on Oct 31, 2014 1:20:52 GMT
I noticed that the image comes from an archery company in the UK shortly after I posted, but various things made me forget to mention this.
Modern bows are more than accurate enough to hit a rope at any distance MB is likely to want to test at - at least initially. The first and most important question is if you can cut the rope, not if you can hit it, so ranged shots for the initial cutting tests are not required. Simulating range is just a matter of varying the draw length. The sights for bows allow for quick alterations, or just as quick as for a gun (and a LOT faster than the 'pop-gun') at any rate.
The required rig for this would be a solid stand which the bow can be secured to, a simple pulley and a draw-weigh gauge. The build team made just such a rig for the wooden tipped arrow myth years ago, and other than the bow everything needed for such a rig is sitting right there in the shop. Heck, they could probably forgo the stand and just use a vice if they had to.
This set up allows for high speed footage of the arrow in flight, which could be important in seeing if the arrow is spinning or, say, to work out if an arrow bounced across the room because it missed and hit the backstop or if it bounced off the rope. They will also be able to use this set up to work out speed of the arrow, and to see first hand how arrows behave in flight - which could be VERY important if they go on to test some types of trick arrows. As they can use the exact same rig to compare the performance of their trick arrows with the more conventional types.
Using the 'pop gun' adds additional and pointless build time and costs for no practical value what-so-ever. Apart from anything else an arrow fired from an airgun is not going to behave the same way as one fired from a bow, if only because the sabot the arrow would have to be placed in would mess up the fletching and reduce the amount of flexing as the end of the arrow would be at least partly supported and restrained by the sabot. Meaning that they'd end up having to use a bow and the above rig anyway.
Testing to see if someone could actually hit the rope is a different series of tests, and one that they can both attempt to do themselves and bring in some world class archers - who will have their own bows to use - to make the attempt at much longer ranges than could be tested in the shop.
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Post by the light works on Oct 31, 2014 1:31:17 GMT
I noticed that the image comes from an archery company in the UK shortly after I posted, but various things made me forget to mention this. Modern bows are more than accurate enough to hit a rope at any distance MB is likely to want to test at - at least initially. The first and most important question is if you can cut the rope, not if you can hit it, so ranged shots for the initial cutting tests are not required. Simulating range is just a matter of varying the draw length. The sights for bows allow for quick alterations, or just as quick as for a gun (and a LOT faster than the 'pop-gun') at any rate. The required rig for this would be a solid stand which the bow can be secured to, a simple pulley and a draw-weigh gauge. The build team made just such a rig for the wooden tipped arrow myth years ago, and other than the bow everything needed for such a rig is sitting right there in the shop. Heck, they could probably forgo the stand and just use a vice if they had to. This set up allows for high speed footage of the arrow in flight, which could be important in seeing if the arrow is spinning or, say, to work out if an arrow bounced across the room because it missed and hit the backstop or if it bounced off the rope. They will also be able to use this set up to work out speed of the arrow, and to see first hand how arrows behave in flight - which could be VERY important if they go on to test some types of trick arrows. As they can use the exact same rig to compare the performance of their trick arrows with the more conventional types. Using the 'pop gun' adds additional and pointless build time and costs for no practical value what-so-ever. Apart from anything else an arrow fired from an airgun is not going to behave the same way as one fired from a bow, if only because the sabot the arrow would have to be placed in would mess up the fletching and reduce the amount of flexing as the end of the arrow would be at least partly supported and restrained by the sabot. Meaning that they'd end up having to use a bow and the above rig anyway. Testing to see if someone could actually hit the rope is a different series of tests, and one that they can both attempt to do themselves and bring in some world class archers - who will have their own bows to use - to make the attempt at much longer ranges than could be tested in the shop. okay, so they introduce the myth, bring in an archer with the bow and arrows, and shoot until they hit the rope. what will they do with the other 50 minutes? |
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Post by OziRiS on Oct 31, 2014 9:04:39 GMT
Show the process of making the arrows, I guess. They are going "back to basics", as we've been told and showing more of the process.
How about testing some of the arrow types from the old Rambo movies while we're at it? That guy had all kinds of different arrow heads that he could screw on, including an exploding one.
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Post by silverdragon on Oct 31, 2014 11:41:42 GMT
I was thinking more at the other end and a "Curtain" of about a dozen ropes or more in close proximity, all weighted, to give numerous targets to hit.... less chance of a miss.
They would have to be free swinging, putting them against a hard target lessens the chance of a tear cut and more of scissor action cut, most myths revolve around a free swinging weighted rope.
If that isnt clear, try swinging an axe at a taught rope, it bounces off, put that rope against a tree, you will get a clean cut...
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Post by Cybermortis on Oct 31, 2014 12:51:42 GMT
Total run time of MB is 43 minutes on average (minus adverts). This is also more or less the average run time for an 'hour-long' show produced in the US or for US TV.
They would set up the basic rig to test the various types of arrow heads in a closed and controlled environment. This allows them to test not only as to if different types of arrows do what they are claimed to be able to do, but to work out exactly how much force is required. That is something no archer could do, as while they can alter the amount of force simply by not fully drawing the bow back they can't do this accurately enough to get a specific figure. (And aiming becomes a problem, as the archer is used to firing at targets at full draw.) Archers are also limited in the strength of the bow they could use - an important point in this specific case because full on warbows were at least three times the draw weight of the average modern recurve or longbow.
Modern bows for men are usually tensioned for a 30lb DW, historical warbows were in the 90-100lb range and English longbows were certainly tensioned for 120-140lbs. The highest draw weight figures I've seen for modern bows were 60lbs for a recurve and 80lbs for traditionally made bows. Coupled with the amount of force needed to hold a modern compound bow at full draw compared to a comparable longbow or recurve and you end up with a situation where those archers who would probably hit a rope might not be able to do so with a bow powerful enough to actually cut it. Bench testing would allow them to find out exactly how powerful the bow needs to be, and if this amount of power is something an average modern archer could match.
Being able to do these tests in the shop saves a lot of time and money, and would give them valuable information as to how arrows actually behave in flight - and in fact it would also allow them to test arrows made from different materials. For the rope-cutter and historical arrow heads you'd be looking at wooden shafts. But if they are also looking into trick arrows from other sources (and they'd probably have to) they would need to look at other shaft materials - off the top of my head the arrows on Arrow are noted as being carbon. This would also be invaluable if they move on to trying to make their own trick arrows, since designing such things wouldn't just be about the arrow head but also about what you make the shaft from.
The last factor (although they would actually put this first) would be safety. Arrows are dangerous, FAR to dangerous to have someone standing there at a fairly close range where they could be hit by an arrow that bounces back in their direction*. A static rig can be setup so that they have the blast shields in place, to prevent that from happening, as well as giving them a consistent aiming point (which even the best archers are not going to be able to match for any length of time). The latter makes missing the target far less likely to start with.
(*The TV show Arrow doesn't use real arrows in their bows, they are CGI additions to the scene. This is purely down to the risk of an arrow bouncing off a wall and hitting someone - and this is with a good archer firing at targets at close range. Of course chances are fairly good that even a fairly low powered bow would be more than capable of putting a broadhead arrow through the walls of most of the sets anyway.)
When they have the data they need they can then move on to doing outdoor testing with a real archer - although A&J could of course try making shots themselves.
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Post by the light works on Oct 31, 2014 14:01:26 GMT
you don't have much in the way of bowhunters in Europe, do you? I'm not sure I've seen a bow with less than 50# draw weight unless it is a children's bow. I know most of the hunting bows I have seen have been 80# draw or more. competition bows will also tend to be higher draw weights, because the higher the DW, the faster the arrow - which means less drop at range.
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Post by the light works on Oct 31, 2014 14:05:58 GMT
and I still favor the air gun, because with that, the arrow can be completely contained until it strikes the backstop - which can be built so the arrow will not ricochet. a clear tube will allow the high speed camera to work, and velocity can be adjusted with air pressure. aim is no longer a factor, because you're at can't miss range; and the rope can be easily adjusted for tension or placed against a backstop to simulate a rope draped over something.
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Post by WhutScreenName on Oct 31, 2014 14:16:44 GMT
Alright, these videos are pretty cool! After watching them both, I have no doubt it's possible. Now to have a good myth to prove it.
And here's one where someone actually shoots a rope with an arrow. While you can't see the tip very well, my guess is that it's a field point (basically a target practice end) and not a broad head.
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Post by silverdragon on Nov 1, 2014 12:45:18 GMT
This looks like a possible good myth to run with.....
I am liking what I am seeing here.
I have a problem with the Air cannon idea though.
If anyone has seen an arrow in flight, it "Wobbles" from side to side, which in some way creates its own flight stability in the way rifling and spinning stabilises a bullet....
If you air-cannon a shaft that is held stable, will it cause problems?...
Plus will the blast in front of the shaft, the bow wave from the air cannon, will that blow the rope away?.....
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Post by the light works on Nov 1, 2014 14:00:50 GMT
This looks like a possible good myth to run with..... I am liking what I am seeing here. I have a problem with the Air cannon idea though. If anyone has seen an arrow in flight, it "Wobbles" from side to side, which in some way creates its own flight stability in the way rifling and spinning stabilises a bullet.... If you air-cannon a shaft that is held stable, will it cause problems?... Plus will the blast in front of the shaft, the bow wave from the air cannon, will that blow the rope away?..... yes, the air blast from the air gun is a concern; which is why I questioned whether it is best to drive the arrow directly with the air or use a plunger like a spring-air rifle. perhaps a vacuum gun like the supersonic ping pong ball gun might work well. the intent is to get the velocity without the wobble and preferably without the spin, which arrows also have. |
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Post by Cybermortis on Nov 1, 2014 17:01:19 GMT
Why waste time and effort trying to come up with some complex way to launch an arrow, and a complex and time consuming build, when you already have the ideal launch system in...a bow.
The main arguments you seem to have for using an air gun (or similar) are;
1; To remove the flexing and/or spin on the arrow in flight.
2; To allow variable velocity in a controlled manner.
My answers would be;
1; You NEED to have flexing and/or spinning of an arrow during testing as this might be a factor in regards what happens when the arrow hits the rope. They need to be able to see and document how the arrow behaves in flight so that even if the basic design doesn't work they could work out why not, and how to possibly make something that would work.
2; A bow can be used to provide controllable and variable velocity/force. You just need a force meter attached to the rope that is being used to pull the string back, and (unlike an air cannon/gun) don't have to mess around making test shots and then doing calculations to estimate what kind of air pressure you will need to hit a particular amount of force. It is fast, simple and straightforward. Allowing them to do more tests in a given period than messing around with an airgun. And if the rig breaks they can repair and set it back up again in a couple of minutes.
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Post by the light works on Nov 1, 2014 19:28:00 GMT
Why waste time and effort trying to come up with some complex way to launch an arrow, and a complex and time consuming build, when you already have the ideal launch system in...a bow. The main arguments you seem to have for using an air gun (or similar) are; 1; To remove the flexing and/or spin on the arrow in flight. 2; To allow variable velocity in a controlled manner. My answers would be; 1; You NEED to have flexing and/or spinning of an arrow during testing as this might be a factor in regards what happens when the arrow hits the rope. They need to be able to see and document how the arrow behaves in flight so that even if the basic design doesn't work they could work out why not, and how to possibly make something that would work. 2; A bow can be used to provide controllable and variable velocity/force. You just need a force meter attached to the rope that is being used to pull the string back, and (unlike an air cannon/gun) don't have to mess around making test shots and then doing calculations to estimate what kind of air pressure you will need to hit a particular amount of force. It is fast, simple and straightforward. Allowing them to do more tests in a given period than messing around with an airgun. And if the rig breaks they can repair and set it back up again in a couple of minutes. 1: not for proof of concept. proof of concept only deals with how fast the arrow needs to be going when it hits the rope in order to cut it, or whether it can cut the rope at all. all that requires is that the arrow be coasting on impact, and that it reliably hit the rope. once you establish whether it can gut the rope at all, then you can start asking whether it can hit the rope in a real life scenario. 2: are you saying there is a chart that shows how many pounds of draw on the bow it takes to generate a certain velocity at range? I think that, in itself, is a myth. also, you can't use a rope to pull the bowstring, because any deflection of the string from activating the release will affect the point of aim - which means you must have a rigid system to prevent deflecting the shot - and once the string is released, the arrow is subject to all of the various possibilities of deflection between the bow and the rope. in consideration, an oir delivery system would need a way to release the force before impact, so the arrow was coasting, but I still think it is a more consistent delivery system, mainly because the arrow can be captive until the point of impact - unless you want to use the bow to shoot the arrow down a guide tube. |
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Post by silverdragon on Nov 2, 2014 12:33:15 GMT
The concept part is not on the arrow, its on the rope.
What constitutes a rope.
The arrow is Lethal, and therefore, we can take as "Known" that it exerts a force equal to x-y-z....
Factor in the use of the English Longbow as presumed used by the hoodie known as Robin of Locksley, as he is notorious for that kind of accuracy.
The unknown here is the rope.
The rope is not a solid unmoveable object, it flexes enough as it is, in a slight wind, it will flex a heck of a lot... which is why I originally suggested a weighted rope.. to give it some form of "stable".
We will be, after all, presuming he didnt just shoot at any bits of rope for fun, he was shooting at either something holding the drawbridge up or something that the Evil Lord John had dangled one of his friends from...?...
But will that create something like a guitar string being strummed by a passing arrow, will it just flex out of the way ....
(And dont pass that idea to any Rock musician... guitar played by Arrow shot?.. )
And then load must also be considered... will a rope with light load resist cutting more than a rope close to breaking point?....
How thick can a piece of string be before its called a rope?...
Plus will the length of rope matter?... will a shorter rope move less [as expected] when under tension...
Is a certain type of rope with 13 turns in it the common hangman's rope, or did they just use anything they can get their hands on?...
The trying to guide an arrow thing is much the same as trying to herd cats.
Didnt they already cover this with trying to split an arrow lengthways?.. its not that easy...
Which is why I am suggesting a curtain of ropes to provide multiple targets so error in aiming is not that important.
Trying to keep an arrow straight will just create friction and slow the shaft down?.... plus whatever rig you have is prone to failure and will need calibration.
I suggest just rig up a free hanging rope curtain and then have at it with a series of known arrow head shapes until you get some form of result... and use that "C" shaped one posted up ^^ there as well.(TLW's post.. )
Then move on to experimental shapes..... if needs be.... I can envisage an arrow head shaped with a bread knife cutting head in a "V" shape, or a super-sharpened carving blade....
Just as a last information consideration, some archery buts are created from very thick Rope formed into a spiral target....
You should investigate the ones that are deemed past their shoot by date... I have, and they are well-knackered....
If the question was can arrows cut into ropes, the answer is already a known confirmed, its just can they cut so much to cause failure.
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Post by the light works on Nov 2, 2014 14:47:49 GMT
the point behind the air gun is that you are doing everything close to the source, so your rope curtain only has to be one rope wide; and while you re not doing precision control - you are also not letting the arrow roam at will - which is what happens when using a bow. now if you wished to still have a spring powered system (which is what a bow is, after all) then you could fire a crossbow through a tube - although it would be miles harder to adjust the velocity of a crossbow bolt. - which was the point of using the pop gun for the motive force - you can simply start with a moderate pressure, and then dial it up until it works or it obviously won't. - from there you will know whether it is reasonable that a bow would develop the velocity necessary.
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