Airsoft gun
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Revision as of 17:07, 22 September 2007
Contents |
Executive Summary
Our team has performed an extensive analysis of the Well's L96 Airsoft gun. Among the major topics that were examined are the customer needs, the system functionalities, a list of components, and the manufacturing process. With regards to the customer needs, we agreed that the purpose of an airsoft is for gaming and emulation purposes. A detailed account of the airsoft's functionality that includes every step from loading the magazine to the firing the BB through the barrel is noted in our report. A preliminary analysis of DFMA, FMEA, and DFE was also performed and the opportunities for improvements were highlighted.
Customer Needs
Airsoft guns are built with two purposes in mind: functionality and emulation. Customers who buy the Well L96 are expecting an airsoft gun that behaves as a sniper rifle should. They will expect the gun to be powerful. Airsoft players with more powerful guns gain a tremendous distance advantage especially in outdoor arenas. An airsoft gun shooting with a muzzle velocity of 300 ft/s has an effective range of 150 ft while as guns that shoot 450 ft/s have effective ranges of over 200 ft. Of course, power is not the ultimate measure of a sniper rifle. A powerful gun is useless if it is not accurate. Customers will reasonably expect an airsoft sniper rifle to be accurate enough to hit a human sized targets at long distances (200 ft). In addition, customers need a durable gun. Durability involves building a gun that can handle environmental fatigue such as excessive sunshine, cold weather and rain. Since airsoft is a physical activity, it also means building a gun that will not break because a player mishandled his gun while doing a physical action such as diving for cover. Finally, the customer has safety concerns that must be addressed. Shooting an airsoft gun can be dangerous if it is misfired. The gun needs to have at least one kind safety mechanism.
Functionality aside, customers buy airsoft guns because of how well an airsoft gun emulates the actual gun. When owning the actual gun is too expensive or is illegal (i.e. Japan), customers buy airsoft guns as substitutes. The most important aspect of emulation is how well the airsoft gun resembles the actual gun. How heavy the airsoft gun is in comparison to the actual gun is also important.
Functionality
Firing this airsoft gun starts with loading BBs into the magazine. Oftentimes, a tool called a "speed loader" is used to aid in loading. As BBs are loaded, a spring in the magazine becomes compressed. The loaded magazine is then inserted into the bottom of the gun. When the magazine is inserted into the gun, the compressed spring pushes the BBs to the top of the magazine and releases a single BB into the gun's loading chamber every time it is cocked to be fired. With ammo ready, the shooter rotates and then pulls the bolt handle back. This pulls back the bolt which then compresses a spring. At a certain pull back distance, which is approximately as far back as the bolt can be pulled back, a knob inside the catches a notch on a piston inside the bolt. This knob will hold the compressed spring in place. The bolt is slid back forward and rotated back to its original position, after which, the gun is loaded and potentially ready to fire. The safety switch, which should be in the "safe" position when not in use, is then switched to the firing position by sliding it forward. The "safe" position is indicated by the safety switch covering the red dot marked on the side of the gun, and the firing position is indicated by a visible red dot. Then, the shooter will pull the trigger to shoot the gun. There is an additional safety on the trigger. Its appearance is a smaller trigger on the main trigger, and it must be pulled back with the main trigger in order for the gun to fire. Pulling the trigger releases the previously mentioned knob from standing up. It releases from the notch in the piston. As a result, the spring will expand quickly. This quick movement pushes the piston forward creating air pressure. The resulting air pressure enters the loading chamber through a nozzle and propels the BB through the barrel.
The Well L96 is classified in airsoft terminology as a spring gun.
Assembly
Manufacturing Processes
DFMA
| Item and Function | Failure Mode | Effects of Failure | S | Causes of Failure | O | Design Controls | D | RPN | Recommended Actions | Responsibility and Deadline | Actions Taken | S | O | D | RPN |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Gun safety | Fracture | Possibility of misfire | 9 | Excessive stress | 2 | Stress analysis | 3 | 54 | Ignore | Trigger assembly | - | 9 | 2 | 3 | 54 |
| Gets stuck | Inability to fire | 8 | Deformation | 1 | Stress analysis | 3 | 24 | Ignore | Trigger assembly | - | 8 | 1 | 3 | 24 | |
| Bolt | Fracture | Possibility of misfire | 9 | Fatigue | 2 | Fatigue testing | 3 | X | Leave as is | Trigger assembly | Leave as is | 9 | 2 | 3 | X |
| Gets stuck | Retarded | 8 | Retarded | 2 | Retarded | 3 | X | Leave as is | trigger assembly | Leave as is | 9 | 2 | 3 | X |
