Knife Throwing - General Discussion

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Knife throwing
From Wikipedia, the free encyclopedia

Knife throwing in the military
Military personnel (usually spec-ops) seldom use "normal" knives for throwing, because lack of repeatability makes training and certification difficult. The French GIGN's knife has a liquid mercury vial hidden inside to help automatically orient the blade forward when thrown. The Soviet "Spetsnaz" throwing knife is actually a blade gun, which uses a very strong coil spring hidden in the handle to propel the blade forward on the press of a button. The holster carries extra blades, because hitting a tree or other wooden object embeds the blade so much, removal by human strength may be impossible. Conversely North Korean frogmen and other elite DPRK troops are skilled in throwing "ordinary" knives as well as other common household objects, e.g. eating forks

O.k.....I know the info on the Spetsnaz Ballistic knife is wrong. It's not that hard to pull out of wood, doesn't go in that deep. I know from experience. And there was no holster for it or 'extra blades' because it was/is a bayonet, but it did come with a blade cover.

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"North Korean frogmen throwing eating forks"

Ummm Yeah...............No.

But I've never hears this one before....

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" The French GIGN's knife has a liquid mercury vial hidden inside to help automatically orient the blade forward when thrown."

I was going to call Bullshit and edit the Wiki...but I had to do a web search first...just to make sure. I found nothing.
Would that even do anything?!?!

We have a post on a straight flying knife, so the idea isn't that crazy.

So, here's my question....How would you design a 'Straight Flying, Hand Thrown' Knife??

Me? ...I used to make spikes as a kid, I'd drill a hole and thread a ribbon to make a tail. I got pretty good at throwing them straight by whipping the ribbon. Also, a spike in a tube givin a good wrist snap will fly pretty straight.

So, not just thowing technique, but what would you do or what would you add to make a blade fly straight?
Also, any comments on the Mercury?

I will think about it, but I don't have time at the moment.

Here's a suggestion: play around by throwing water bottles with varing amounts of water in them. If a liquid contained inside a device is capable of turning rotational flight into straight flight, this should let us know.

SINZA wrote:

So, here's my question....How would you design a 'Straight Flying, Hand Thrown' Knife??

this

accuflight easy stick
[img][/img]

usually im a little oldschool in that I believe you should never throw your weapon, but id make an exeption with this knife, its basicly a giant dart and it would suprise the shit outta anyone who thought that because they were just outta reach they were outta range

a quick 5' throw into the gut before they even realize you have a knife and rushem to finish them off

Liquid mercury,
A liquid inside an object in motion will always make it less stable.
Spin a raw egg, spin a hard boiled egg.
Racing cars ( all cars for that matter ) have baffles inside the gas tanks
to keep fuel from sloshing around.
Without a baffle, you would need very slow acceleration rates.

Liquid mercury inside a stationary object makes it more stable.
Liquid has a motion dampening effect.
Inside a plum bob, ( a surveyors weight on a string )
you see them hanging under a transit, or theodolite
pointing to a specific benchmark or monument.
is designed to keep a static motionless point , on center.
Carry a bowl of water.
When you move the bowl, the water tends to stay where it was,
then it moves after the fact...

In large buildings, the water supply in skyscrapers for fire systems
is a big enclosed tank on the upper floors.
There are detailed architectural designs for earthquake proofing buildings.
Like a guitar string, sine wave, from cycle to cycle
the size and shape will determine where the building will
move and when there are harmonic calm points.
Where it is easier to store water.

If water were in a cavity with an air bubble, the flight would be erratic,
causing a tumbling effect, as the liquid behaved in a delay with the outside container.
If water were in a cavity without any free space, or air bubble,
what would be the point ?, why not just have a solid mass of equal density.

Extreme sudden acceleration may cause cavitation, or "soda pop fizz".
I recall reading about mercury filled bullets, how they would be unstable.
Also, explosive gels in artillary shells have to be thickened to a certain point.

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If water were in a cavity with an air bubble, the flight would be erratic,
causing a tumbling effect, as the liquid behaved in a delay with the outside container.

I think that's the point. The delayed motion of the fluid is supposed to help counteract the rotational force of the object. I tried throwing some water bottles around. It seemed to me that the rotational speed of the 1/4 filled bottle slowed down faster than the full bottle. I don't know if you can go from "it rotates slower" to "it stops rotating midflight" or not, but the concept may be valid.

Still, for this to work I think the liquid has to be able to slosh around the entire length of it's container, so the mercury would have to have the mercury for the full length of the knife, not just the handle.

P.S.
I could very easily be wrong about any or all of this.

but your the only one to attempt an experiment so Im prepared to listen to your results with an open mind, regardless of how preposterouse the idea sounds

playing devils advocate,

a liquid filled object at rest is more stable theirfore a liquid filled object at constant velocity would share the same properties.

since the deceleration caused by air drag is minimal on a straight flying knife the most unstable part of the flight is the accleration while your hand is stabelizing the flight

since a tumbling knife involves both acceleration and deceleration while in flight it makes sense that it would be extremly unstable but there are techniques for throwing a knife with no spin/quarterspin so that each point on the knife would travel with near constant velocity


(its not the best but because of the snow you can see the path of the shuriken)

if there is any truth to this it is that a liquid filled knife may be easyer to throw with "no spin" ... or not

Well I'm with jerry on this one. It's hard enough to balance a knife without sticking a vial full of a shifting fluid in it...

The problem with a fluid chamber being used for stabilization is that the fluid would be subject to every force acting on the knife, and will change positions in response. Mercury is a very mobile fluid. It's not thick, like molasses. It's not called "quicksilver" for nothing. It will move given the slightest provocation. So I do not beleive there will be a delay or dampening effect in using a Mercury vial in a knife.

Also, an important aspect of a throwing knife is not how fast it rotates, but rather how consistently it rotates. Small knives rotate faster than big ones. But so long as they rotate uniformly, with proper technique, they can be thrown to hit a target, point forward, consistently.

If you have a knife whose center of gravity keeps shifting due to fluid moving around, then it will rotate in an erratic fashion and make for a horrible throwing knife. So I'm thinking, based on those points, the whole mercury thing is a crock.

So far as how to make an easy to throw knife, actually the accuflight would be my first choice. Perhaps with a little more blade and a little less fletching, but the same basic design...

yep.

I agree with most of what you said

i was just adding a point of view that hadnt been explored and coming up with a functional theory that a knife thrown that undergoes less than half a revolution would be the most likely case for the fluid filled knife as the fluid would experience the least acceleration/deceleration

the reason for this is the top of a tumbling knife has greater velocity than the center of gravity and the bottom has less, so when the tip (if it starts at the top) crosses the horizontal boundary it decelerates and the handle accerates (vice versa at 180) the more this happens in flight the less it resembles a particle at constant velocity

newtonian physics have the same effect on a particle at rest as a partical at uniform velocity. a liquid resevoir has a damping effect on a partical at rest and will then have a damping effect on a partical at uniform velocity reducing accelerations/decelerations

so the closer the knife can replicate a partical undergoing constant velocity throughout its flight, the less it will want to deviate from that path
EDIT: meaning the less it spins the less it will want to because of the damping inertia provided by the fluid

so a dart thrown straight or a knife thrown with quarter spin is the best candidate for experimentation and will most likely produce the best results

BUT that does not guarrante good results there are many things not factored in: acceleration due to gravity, decceleration due to drag, the initial launch is compleatly over looked on the hope that the system will have stabelized by the time its left your hand, which it may not depending on the length of yor arms and the speed you are hoping to throw the blade at, and can the blade even physicly achieve a flight that resembles a particle with constant velocity when subjected to real world conditions

the most important thing however, is that even if it works there are simple ways to achieve flight stability and you can avoid the whole mess with flights/sinzas ribbon and distributing solid weight properly. why dont you see darts with liquid resevoirs? because they have better ways to achieve the needed results.
sorry if you actually read the whole thing, you really only have to read the last paragraph

you forgot about the way centrifugal force will act on the liquid inside the knife.

Yeah, I agree, although you might get liquid to work reliably and consistently, it would be much easier, and give the same results to just use solid weight.

Yeah, I knew it was BS...but I had to make sure because...you never know.

Like I said, all the other info was wrong, so I figured this was way off.

The Accuflight is kind of what I used to make years ago, but of course nicer.

I also used to take these needles we had at work, they had a eye loop at the end. I'd tie about 3 inches of string on the end and whip them across the room.
You know...un-safe ways to kill time at work...
I'd take two staples, bend one prong on each so it was bent the other direction, then place them at the end prongs out, wrap string around the end. This made it look like a 4inch Sai with a wrapped handle and tassles. Those were fun to toss around, stick into cardboard or wood pretty good. I made these about almost 20 years ago and I think I still have one left.

Ever play darts and throw them like knives? There were a few times I was in a bar playing darts, but I'd hold it by the tip and throw it like I was throwing a knife. Those still stuck pretty much every time and fairly accurate too.

so, is a dart the answer? Heavy pointed front end with very light finned tail end.

Maybe somethingtwice the size of normal game darts. A 3inch spike/blade....(here's where I stopped to search, better to answer my own question)

Here.....


Then I found this...and figured I might as well stop.

Secrets of Shuriken-Do

Now I feel like I'm right back at 13years old reading Ninja books by Hatsumi Sensi.
::

does any army actually issue knives designed primarily to be thrown? That seems rather foolish to me. There are so many things you can do with a regular knife, including throwing it if you have to. But those specialized throwing "knives" those dart things, what can you do with them besides throw them, maybe stab?

@Sinza
Yep, I'm thinking the dart, needle or knife with a tail, tassel or fletching is perhaps the best throwing design, due to it's self stabilizing ability...

@Dach
To my knowledge, there are no armies that I am aware of that issue throwing specific knives as standard, which makes sense for the reasons you mentioned. Most armies issue general purpose battle blades, bayonets, or close quarters fighting blades. But while most of them can be thrown with a little practice, it is not encouraged, because from a battlefield perspective, throwing one of your only close quarter combat weapons at the enemy with a very low probability of a hit, as compared with hand to hand use, has traditionally always been considered a rather foolish idea...

and throwing knives arent that lethal to begin with so what purpose would the military have for one. its not really a silent killer if the guy you hit is running around screaming because you through a pub dart in his back and if silence isnt nessasary then why not shoot them. its much easier to pack one more bullet then a giant dart. now a russian spetsnaz fightin shovel, theres a weapon to get exited about

Read "All Quiet on the Western Front" by Erich Remarque.

There is a part in the book where two germans are talking in WWI trench,
and the older sargent tell the private to throw away his knuckle knife,
and carry a sharp shovel. The allies won't kill you if you're just carrying a shovel.

from what I remember from that book it was the serrated bayonets that the younger soldiers were sent to fight with that were a problem and you would get your nose and ears cut off if you were caught with one. so the older guys told the younuns: get a new bayonet, grind off the serrations or better yet sharpen your shovel because its easyer to swing in the trenches

@Zigged,
I wouldnt go so far as to make the blanket statement that throwing knives aren't as lethal as anything else. As with anything, it depends on the knife.

When I was learning how to throw, I remember reading a story about a famous old native american knife thrower, (I think his name was Skeeter "The Chief" Vaughn) who during some war (can't remember which one) used a throwing knife to kill a sentry at an extreme range.

According to the writer, this sentry was so far away, that skeeter had to throw the knife with a ballistic trajectory (actually threw it at about a 45deg angle) to actually hit him. Clearly this was a really risky move, as if it missed, it would most certainly have alerted the guard.

But apparently, hit and kill him it did. There was even a story about a hunters using bowie throwing knives to hunt 750lb wild boar. So lethality is less of an issue as much as accuracy, consistancy and reliability. And the one thing that the vast majority of these cases have in common are that the thrower had extra knives, and had spent a lifetime learning how to throw them.

Your average soldier... not so much experience with throwing, and no spare knives. But I'd have to agree that sharpened shovels are perhaps the single most useful bladed implement you can have for most environments.

"what happened to you?" "i got stabbed by a shovel"lol.

but yeah i always thought the special forces shovel was a great multi-use tool!

I stand corrected, the shovel from western front was with the serrated stuff,
the trench knife bit I think was from Slaughter House Five .

First of all, I'm totally against the idea of throwing knives. Even with a good lot of practice you have at least a 50% chance of missing or only inflicting a minor wound. If you are armed with a knife only, wtf would you throw it away ?? Makes no sense
The german soldiers used sharpened entrenching tools like these http://www.epicmilitaria.com/product.php/1236/german-entrenching-e-tool with great success in WW2 because knives are no good if the enemy is dressed in 3" thick clothing in winter.
Somewhere is a vid on a Hungarian (?) military knife that are thrown from the sheath apparently with great accuracy. Can't find the darn thing right now.

Alright first post, I don't want to waste my quick train of thought so I'll save "formal" introductions for later, alright.

One thing about knife throwing is, you can get it pretty deep with enough skill, and that would be using a quarterspin throw thanks to the teachings of Ralph Thorn and Fedin.

Fedin