27-01-2011

Colt 1911 Disassembly

The link below will guide you to a movie that shows how every part in the gun is connected. As you will see most parts rotate around pins that can easely be removed by pushing them out. The only screws are the ones who keeps the grip in place.

http://www.youtube.com/watch?v=SEBrkF0sMgI&feature=related

26-01-2011

Final presentation

Below you can find my final presentation. I made a movie of aproximatelly 9 and a half minutes to explain how handguns work. Details of how every part works you can find below in my blog.

24-01-2011

Myth : will a bulletimpact cause you to fly backwards?

We have all seen it in the movies, a bad guy gets shot and because of the impact of the bullet he flies backwards. Is this real or movie myth?
Well as a massive fan of Mythbusters I was very eager to find out. And I think they came up with a logical explanation why it is a movie myth. They tested this myth by shooting the biggest possible caliber they could find, which is the 50. Cal from Barret sniper rifle at a test dummie. They even made him wear a bulletproof vest so the kinetic energy of the bullet would transfer to the entire body instead of just piercing it.

As illustrated in the movie below they found that we had to Newton’s law into account. If the guy would fly back the shooter would have to fly back an equal distance. Every action has to have an equal yet opposite reaction.

Forces, pressure and speed

What I love about guns is the ability of making something small into something enormous. When we compare the force that is required to squeeze the trigger, which is around 14 Newton, to pressure behind the bullet when it ignites, which is 82,7 MPa, we can see that the initial force has been enlarged. I have to add that the final force on the primer of the bullet is 104 N. This force is caused by the push of the coil inside the grip. The exponential increase of pressure has almost no relation to the striking force on the primer. It is mainly the force of the explosion behind the bullet of the propellant due to the chemical reaction with the primer.
Because of the enormous pressure behind the bullet, the bullet will exit the muzzle with a speed of 330 meter per second, which is almost equal to the speed of sound (340,29 mps).

18-12-2010

Complete list of parts and technical details

If you want to see all the parts with all the measurements you have to look at the pdf underneath. Based on that info and assuming you have the right tools, you would be able to manufacture your own Colt 1911, which is something I recommend to nobody. But it does contain a lot of interesting information.

http://stevenvanwettere.be/colt1911.pdf

13-12-2010

Materials

Through the years a lot of different versions of the Colt 1911 have appeared. The main difference between those guns are the use of materials. In the example of the 9mm the most common material is steel. For the grips they used molding plastic. But as you can see in the image below there are different kinds of materials that can be used. In the Colt 1911 Government they used carbon steel for the frame and aluminum for other small parts for example the trigger. And the grips are made out of rosewood.

Safety mechanisms

A very important feature of the gun is the safety mechanisms. They will decrease the number of accidental gun casualties. The Colt 1911 has 3 safety features. The first one is located inside the grip, it blocks the backwards movement from the trigger by blocking it. When the grip safety is pushed the part that blocks the trigger will rotate out of the way enabling the trigger to pass.

The second safety is the most know, the thumb safety. This feature blocks the sear from rotating out of the way. By blocking the sear the hammer will not be able to be released, so it is impossible to fire.

The last safety is located inside the barrel, and is designed to prevent firing when the gun would fall on the ground with the muzzle. The safety blocks the firing pin from passing, only when the trigger is squeezed the safety will release the firing pin.


26-11-2010

Cocking phase

The cocking phase is where the Colt 1911 differs from single action weapons. It means that this weapon automatically arms the pistol for the next shot, by pulling back the hammer. When the slide is moving backwards it pushes against the hammer which causes the hammer to rotate to its starting position. The mainspring will be pushed back and because the is no more pressure on the trigger, the sear will stop the hammer from rotating and firing again. The gun is now ready to fire the next bullet.

Ejection and reloading

Now let’s see how the empty bullet case gets removed from the barrel and a new bullet takes place.

Because of the backwards movement of the slide, the bullet case also moves backward. Once the slide is completely at the end, there is an opening in the slide that corresponds with an opening in the frame just large enough for the case to be ejected. Because of the kinetic energy from the backwards movement of the case a little tap of a pin at the end of the barrel is enough to shoot the case out of the barrel. Now the case is gone it is no longer holding down the new bullets inside the magazine from going up. The magazine spring underneath the bullets constantly pushes the bullets upwards. It is the slide that returns to its starting position that pushes the new bullet inside the barrel.



Barrel linkdown

Barrel linkdown is essential for a number of reasons. First of all it causes the slide to come loose of the frame which makes it able to slide backwards. It also makes it possible to eject empty bullet cartridges and provides an angle with the magazine so a new bullet can slide into the barrel.
Under pressure of the shot the part underneath the barrel called the barrel link will rotate 45 degrees which causes the entire barrel to rotate a few degrees. Because of the recoil spring, the barrel link will rotate back up again after the shot.

16-11-2010

Pressure and reactions

Now we are going to look at how the slide of the gun is pushed backwards and returns to his starting position. The explosion inside the barrel causes a enormous pressure buildup which causes the bullet to go forward. Once the bullet has left the barrel the pressure will only be pushing to the back so the slide will be pushed backwards over the frame. Once the pressure has escaped a coil underneath the barrel will expand again causing the slide to move back to his starting position.

Technical details of this coil.

Forces of the coils

The recoilspring has a normal length of 6,55 inch (=16,6 cm), inside the gun she is compressed to 9,4 cm when the gun is not active. When the gun is active and the slide moves backward the coil is compressed to a length of 4,59 cm which will increase the force that the coil generates.
From the technical details we know that the k value which is the spring rate of the coil is equal to 2,88 pounds per inch (= 51,4 kg per meter).

When we use the Hook’s Law we can calculate the forces generated by the coil.
F= k*∆L

In inactive state the compression is equal to : ∆L= 16,6 cm – 9,4 cm = 7,2 cm
F = 51,4 kg/m * 0,072 m = 3,7 kg
We have to multiply by 9,81 m/s² to get F in Newton!
So 3,7*9,81 = 36,3 N

When the gun is fired the compression is equal to : ∆L= 16,6 cm – 4,59 cm = 12 cm
F = 51,4 kg/m * 0,12 m = 6,17 kg
We have to multiply by 9,81 m/s² to get F in Newton!
So 6,17*9,81 = 60,5 N

Firing mechanism

Because there are a lot of mechanisms inside a gun that happen simultaneously it is better to look at every mechanism at a time to put them all together at the end. The first mechanism is the firing mechanism.

When we pull the trigger, the trigger pushes a small piece of metal which will push the sear spring. The sear spring will rotate the sear so the hammer can rotate towards the striking pin. The hammer will rotate because in the handle there is a coil that is constantly pushing the hammer. The sear is the part that prevents that from happening until the trigger is pulled.
The hammer will hit the striking pin which on his turn will strike the primer of the bullet.



Technical details of this mechanism are mainly the characteristics of the coil.

Forces of the coils
The main spring has a normal length of 2,156 inch (=5,476 cm), inside the gun she is compressed to 2,697 cm when the gun is not active. When the gun is active, when the coil is released she will expand to a length of 3,33 cm.
From the technical details we know that the k value which is the spring rate of the coil is equal to 27,69 pounds per inch (= 494,7 kg per meter).

When we use the Hook’s Law we can calculate the forces generated by the coil.
F= k*∆L

In inactive state the compression is equal to : ∆L= 5,476 cm – 2,697 cm = 2,779 cm
F =494,7 kg/m * 0,02779 m = 13,7 kg
We have to multiply by 9,81 m/s² to get F in Newton!
So 13,7*9,81 = 134,4 N

When the gun is fired the compression is equal to : ∆L= 5,476 cm – 3,33 cm = 2,143 cm
F =494,7 kg/m * 0,02143 m = 10,6 kg
We have to multiply by 9,81 m/s² to get F in Newton!
So 10,6*9,81 = 104 N

So we can see that the force that will hit the striking pin will be 104 N, because the coil gets bigger it loses energy and force.

Different kinds of guns

There are a lot of different kinds of guns, also a because there are a lot of aspects where a gun can differ from another. For example, there are single action guns as there are double action guns. Single action weapons don't automatically recock. Which means that every time a bullet is shot the gun has to be manually recocked to fire the next bullet. Unlike double action weapons who recock automatically when the slide moves backwards.
Another major difference is the type of gun. Revolvers are guns which have a cylindrical bullet magazine, where pistols have a bullet magazine that stacks the bullets on top of each other.


The size of the bullet that the gun uses is called the difference in caliber. The caliber that the Colt 1911 uses is a 9mm. The 9mm stands for the diameter of the bullet.


And maybe the biggest differences in guns is found on the inside. There are a lot of different kinds of mechanisms inside a gun. Every mechanism can vary in guns.

How bullets work!


To understand how handguns work we first need to know how a bullet works. A bullet consists out of 5 important parts. The bullet (1), the bullet case (2), the propellant (3), the rim (4) and the primer (5). When the striking pin of the gun hits the primer a small chemical reaction will occur that gives a spark to the proppelant. The proppelant will ignite wich will lead to a massive pressure build-up behind the bullet. The pressure will look for a way out, the least resistant captivator is the bullet, so the bullet will be pushed forward through the barrel by the pressure of the explosion behind it.

The pressure behind the bullet in the Colt 1911 is aproximatelly 82,7 MPa!

14-10-2010

Leren begrijpen

Om de werking van de Colt te leren begrijpen probeerde ik zo veel mogelijk informatie te vergaren. Om te beginnen kwam ik natuurlijk terecht bij wikipedia waar ik zowat alles van de geschiedenis van het wapen kon terugvinden.

Over de werking van het wapen staat er echter weinig informatie op wikipedia. Ik ging dan maar verder zoeken en kwam bij een filmpje dat aantoont hoe alle parts van het wapen in elkaar passen en moeten worden geassembleerd. Dit toont niks van de werking van het wapen, maar geeft wel al een eerste indruk over hoever de complexiteit zich zal uitstrekken.

Informatiefase

Vooraleer ik het principe en de werking van de Colt M1911 kan uitleggen aan anderen dien ik zelf te begrijpen hoe alles in elkaar zit en samenwerkt. Voor zelf inzage te krijgen hierin heb ik het internet zo goed als mogelijk proberen te doorzoeken op alle nuttige info die me daarbij kan helpen.

Verfijning opdracht

Omdat het uitleggen van de werking van een pistool vereist om het mechanisme uit te leggen van trekker tot slagpin dienen we te gaan onderzoeken welke mechanismen er zoal bestaan. In de presentatie zullen enkele veelgebruikte mechanismen worden getoond, en zeer kort worden besproken. Het is echter onmogelijk om op korte tijd alle verschillende mechanismen uitgebreid te bespreken.

Om dit op te lossen heb ik 1 model van pistool gekozen dat ik volledig zal gaan bespreken. Eenmaal de toeschouwer inzicht krijgt in de werking van dit pistool kan men de afleiding naar andere pistolen makkelijker volgen en begrijpen. De keuze van wapen heb ik gedaan aan de hand van de hoeveelheid informatie die te verkrijgen was op het web. Na grondig onderzoek is gebleken dat er 2 wapens zijn die nogal populair mogen genoemd worden. Dit zijn de Colt M1911 en de Beretta 92fs. Van deze wapens is er heel wat informatie voor handen, en heb ik hieruit 1 van gekozen. Men keuze ging naar de Colt M1911. Ik had echter evengoed de Beretta kunnen kiezen omdat het trigger mechanisme voor beide wapens zo goed als identiek zijn.



Om mijn presentatie zo duidelijk mogelijk te maken ga ik trachten een 3D animatie te maken van dit wapen en zo proberen hoe de 57 onderdelen met elkaar samenwerken. Om dit te kunnen verwezenlijken heb ik na heel wat zoekwerk de nodige informatie vergaard om een exact 3d model te kunnen beginnen maken in een technisch 3d softwarepakket. Nadien zal ik dit model exporteren naar 3ds max, en daar het animeren.

Opdrachtstelling

Mijn opdracht bestaat uit het analyseren en visueel duidelijk maken van de werking van een pistool. Op deze blog kan je het proces van informatiefase tot uiteindelijk presentatie en ontwerpdossier terugvinden.

De bedoeling is dat in na mijn presentatie gezien te hebben iedereen de werking van een pistool volledig begrijpt. Om dit op te doen ga ik gebruik maken van zoveel mogelijk visueel materiaal in combinatie met de bijpassende uitleg.