SpudFiles

WOW!! This is no doubt the coolest slingshot you've ever made!!!!!! Pirates is one of my favorite movie series...

Nice, Im sure people will want a tutorial, especially since this has a different trigger mechanism.

Here is the video.

Not only did you make a pirate pistol, but you made a pirate out of ballistics gel! And then you eat it!!

Top notch video. Informative, cool to watch, and well humored.

After the winch operated cannon and the "Ballista" slingshot, The Slingshot Channel continues to combine medieval siege engine technology with modern rubber. This time, a long throwing arm is powered by a lot of pre-tensed rubber. The weapon is cocked much like a break barrel air rifle, and then a 20 mm steel ball is put on the "spoon" shaped end of the lever, held in place by a neodyme magnet.

The trigger works much like on a crossbow or firearm.

The video includes impressive super slow motions of the shot, recorded at 1200 fps with the Casio EX-F1 Pro camera.

It's a good thing your on our side, (Spudfiles) lol. Nice work! I'm impressed and that don't happen easily. What are you going to think of next?

jrrdw wrote: What are you going to think of next?

slingshot icbm

Here:

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How do you know the ball won't hit the top of the first two slingshots when you shoot it? Very nice by the way... made me laugh..

Every time you shoot, turn around and look at the camera its almost as if you're saying "You're next!"

The antler handle one looks amazing. The fork emulates the antler shape.

Good to hear that your metal working tools are back though. Can't wait to see what you'll be showing us next.

Every time you shoot, turn around and look at the camera its almost as if you're saying "You're next!"

Seconded.

Gaderelguitarist wrote:

Every time you shoot, turn around and look at the camera its almost as if you're saying "You're next!"

Seconded.

Thirded

I just received my copy of Richard Middleton's interesting book "Man powered bullets".

It was printed before I got into slingshots (book is from 2005), so none of my devices are mentioned

But there is one thing mentioned right at the start that got me thinking: The pendulum test.

Mr. Middleton's conclusion is that man powered bullets will always be slow (in comparison), but can be very heavy.

The formula for energy is e = 0,5*mass * speed * speed. So even a .22lr bullet will show much more energy than even my strongest slingshots - because the speed is squared in the energy formula and only half of the weight counts. Yet when fired into ballistic gelatin or even into water, the slingshot ball will cause a lot more damage and travel more far.

Mr. Middleton employs a different kind of test. He uses a pendulum and shoots against the lower end of it. The more it swings, the more momentum got transferred.

And it happens that a slingshot ball will move the pendulum much more than an air gun pellet or even a .22lr. And he uses fairly weak slingshots.

Momentum, as Mr. Middleton points out, is just mass times speed.

Let us compare.

The .22lr (I am using a yellow jacket HP hispeed type now) flies at 440 m/s and the bullet weights 2 gramms.

That is 194 Joules of energy.

My strongest handhelds shoot a 36 gramm .75 lead ball at 75 m/s.

That is 101 Joules.

So one could assume that the .22 is almost twice as powerful. But let us look at the momentum side.

.22 HP HS long rifle: 0.88 Newton
.75 "slingshot": 2.7 Newton

The pendulum swings out three times more far when you hit it with a slingshot (albeit a serious one).

So not only does the slingshot ball outperform the .22lr Hispeed, it even outperforms a .38 Special - which has 319 Joules of energy, but delivers only 2.13 Newton of momentum.

The slingshot is - momentumwise - on par with the 9 mm Luger (9x19 Parabellum), which brings 2.9 Joules, and just a bit under the mighty .45 ACP (3.4 Newton).

Of course the high speed of the firearms bullets have a lot of advantages. They don't drop as fast when you shoot long distances. The have way better penetration through fabric, skin and bone. But if you look at how much momentum they transfer, slingshots can compete pretty good.

Jörg

PS: I recommend the book! Worth every penny, and you will have a good time.

Interesting comparison.

Let's take fast baseballs, it seems 45 metres per second is more than possible thrown by a fit individual, for an average weight of 145 grams.

This gives the ball a momentum of 6.5 Newton, almost twice that of a 45 ACP.

I would take a baseball to the chest over two 45 slugs any day

JoergS wrote:Of course the high speed of the firearms bullets have a lot of advantages. They don't drop as fast when you shoot long distances. The have way better penetration through fabric, skin and bone. But if you look at how much momentum they transfer, slingshots can compete pretty good.

This is the point really, when it comes to "lethality" it's not a question of momentum or energy, but how that energy is used. It's all dealt with in detail in this FBI reportwhich is a fascinating read.

in conclusion they wrote:Kinetic energy does not wound. Temporary cavity does not wound. The much discussed "shock" of bullet impact is a fable and "knock down" power is a myth.

The critical element is penetration. The bullet must pass through the large, blood bearing organs and be of sufficient diameter to promote rapid bleeding. Penetration less than 12 inches is too little, and, in the words of two of the participants in the 1987 Wound Ballistics Workshop, "too little penetration will get you killed." Given desirable and reliable penetration, the only way to increase bullet effectiveness is to increase the severity of the wound by increasing the size of hole made by the bullet.

Any bullet which will not penetrate through vital organs from less than optimal angles is not acceptable. Of those that will penetrate, the edge is always with the bigger bullet.

This is not to say that a slingshot is not potentially lethal, I think the best comparison would be to older black powder type weapons, that fired large projectiles at relatively low speeds. Going by cross-sectional area, fluids can potentially flow through a 0.75" hole almost 12 times faster than a 0.22" hole. There is also a tendency of such projectiles to shatter bone into hundreds of secondard fragments, as opposed to drilling neat holes through it like modern high velocity projectiles.

The above discussion is purely academic of course, only shoot inanimate objects

I have a question... does longer bands = better accuracy? Assuming the release mech and ammo are constant and all that...