*Gate 4: Product Explanation

Revision as of 02:44, 29 November 2012

Project Management: Critical Project Review

Cause For Corrective Action

Since the last submission of the project, the design team has been functioning extremely well. The only problem the group faced during this time was the addition of the PowerPoint section of the project to the original gate and group members leaving earlier than planned for the holiday. After an honest and open talk, at the November sixteenth meeting by all of the group members, a compromise was made. The compromise made was to meet several times the week after Thanksgiving as well as complete part of the project over break in order to make sure that everything was finished on time and completed to the best of the group's ability. The next two weeks were then planned out and occurred as the following:

• November 16: future team meetings were finalized and the work to be completed over break was divided, including work on Gate 4 and revising the previous gates.
• November 26: the parts of the gate finished over break were combined and uploaded followed by a discussion of the PowerPoint as well as the breakup of work for it.
• November 27: combined the PowerPoint slides and finalized the presentation.
• November 28: process, write up, and upload of the reassembly.
• November 29: the group reviewed, corrected, and revised the gate as well as the PowerPoint. The PowerPoint was then emailed to the professor.

This design team was successful on this gate because they resolved their challenges right away with open communication as well as planned out the work that needed to be done ahead of time. Future problems, just like those previously faced by the group, will be resolved by honest, open talks along with fair compromises for each design team member. Flexibility, compromises, commitment, and teamwork are what made this team successful.

Product Archaeology: Product Explanation

Product Reassembly

After addressing the unresolved challenges and how these were overcome, Group 5 began the process of reassembling the Nerf N-Strike Longstrike CS-6. Throughout the assembly process, a camera was used to photograph each step of the process; information and observations were also recorded. The purpose of the reassembly process was to put the Nerf gun back together to its original form when the team first received the product, and then analyze the information gathered and make detailed conclusions about the product.

Reassembly Process Overview

After addressing the unresolved challenges and how these were overcome, Group 5 began the process of reassembling the Nerf N-Strike Longstrike CS-6. In Gate 2, the team decided that the best plan of attack was to disassemble the least complex components first and the more complex ones last. However, Group 5 decided that the most efficient way to reassemble the Nerf gun was to assemble the most complex components first and end with the assembly of the simple components. The rating scales used to determine the complexity of each component is further discussed below. The reassembly process took only one day to complete within the time span of three hours. Similar to Gate 2, the team divided the process into five phases; the reassembly of the Base, the Shoulder Stock, the Flip-Up Sight, the Quick-Reload Clip and the Barrel. The first hour of the process was spent assembling the Base, which proved to be challenging with the many small parts that had to be put into place on the component. Brianna and Sarah worked together by analyzing each individual part and, by referring to photos documented from Gate 2, were able to figure out where the proper place was for each part. The final two hours of the process were spent assembling the components in the next four phases. With the help of a screwdriver, Brian was able to attach many small parts, as well as assemble the main components. Throughout the entire process, Bryan used a digital camera to record each step as well as document every step for each phase. After three hours the team was successfully able to assemble the Nerf gun. The step by step procedure is listed below.

Ease of Reassembly

In order to safely, successfully, and efficiently reassemble the Nerf N-Strike Longstrike CS-6, each step of the assembly process was recorded. The assembly process is shown in the table along with the steps that were necessary at each phase. There were some difficulties associated with each process of the assembly which was predicted since each part of the Nerf gun has a different level of complexity. Group 5 divided the difficulty of reassembly into three different complexities; Connection Complexity, Force Complexity, User Complexity. Each complexity uses a rating scale ranging from one to three. Each scale is described in detail below.

Connection Scale:

1. The part is connected in only one place and is attached to another part by either snapping or a screw. The connection is can also be made by the parts strategic placement which holds it in place.
2. There are two to four connections between the parts and the connections consist of either snap tabs or screws.
3. There are five or more connections between parts. These connections consist of snap tabs, screws, nails or glue.

Force Complexity:

1. The assembly of the part requires no force and no use of a screwdriver.
2. The assembly of the part requires some force, as well as a screwdriver.

User Complexity:

1. Only one person is necessary to reassemble the part.
2. More than one person is necessary to reassemble the part.

Reassembly Process

Phase 1 : Reassembly of the Base

Step	Description	Tool Used	Time Required	Difficulty: Connection Complexity	Difficulty: Force Complexity	Difficulty: User Complexity	Notes
1	Insert the following parts into the Main Base: Base Spacer Internal Spring 1 Connection and Internal Spring 1 Trigger Divider 2 Internal Spring 2 Connector and Internal Spring 2 Internal Spring 4 Connector and Internal Spring 4 Internal Spring 5 Spring Support 1 and Spring 1 Internal Spring 5 Connector Divider 4	Hands	04:45	1	1	1	Before: After:
2	Insert the Internal Air Shaft Spring onto Air Chamber 2. Then insert Air Chamber 2 onto Air Chamber 1.	Hands	00:20	1	1	1	Before: After:
3	Insert the Nozzle Divider.	Hands	00:05	1	1	1
4	Screw two steel screws into Nozzle Divider to attach the part to the Main Base.	Philips head Screwdriver	00:45	1	2	1
5	Insert the Air Chamber/Spring System into the Main Base of the Nerf gun.	Hands	03:00	2	2	2	The Air Chamber/Spring System must be in between the Internal Air Shaft as well as the Nozzle Divider to allow for the Nerf gun to function properly. This step proved to be challenging and will be discussed in more detail below.
6	Screw one screw into the each of the Base Spacers.	Phillips Head Screwdriver	01:00	1	2	1
7	Place one Clip Button underneath the Main Base directly under Divider 2. Screw a small screw into Divider 2, connecting the two parts.	Phillips Head Screwdriver	02:00	2	2	2	When properly attached, the Divider 2/Clip Button system will slide from left to right and aids in the removal of the Quick-Reload Clip from the Main Base of the Nerf gun.
8	On the second half of the Main Base, place the second Clip Button underneath the Main Base directly under the divider. Screw a screw into Divider 3 connecting the two parts.	Phillips Head Screwdriver	02:00	2	2	2
9	Attach Divider 1 to the Main Base by screwing the third steel screw.	Phillips Head Screwdriver	01:50	2	2	1	Before: After:
10	Attach the Clip Hook into the Main Base of the Nerf gun.	Hands	00:25	1	1	1
11	Place the second half of the Main Base on top of the first.	Hands	00:10	2	2	2	The screwdriver must be used to push the Air Chamber system down in order for each half of the base to successfully attach to one another.
12	Screw sixteen screws into the Main Base of the gun to attach both sides of the Main Base together.	Phillip Head Screwdriver	05:00	3	2	1
13	Insert half of Cocking Bolt with steel rod through the Base and connect with the second orange knob.	Hands	00:15	1	2	1

Phase 2: Reassembly of the Shoulder Stock

Step	Description	Tool Used	Time Required	Difficulty: Connection Complexity	Difficulty: Force Complexity	Difficulty: User Complexity	Notes
1	Place the Clip Storage on each half of the Shoulder Stock.	Hands	00:10	1	1	1	Before: After:
2	Screw three screws to attach Clip Storage to the Shoulder Stock.	Phillips Head Screwdriver	03:00	2	2	1	Be careful not to strip screw heads when screwing in the small screws.
3	Place the second half of the Shoulder Stock on top of the first.	Hands	00:20	1	1	1
4	Screw in eleven screws to attach the two halves of the Shoulder Stock.	Phillips Head Screwdriver	05:30	2	2	1	Before: After:

Phase 3 : Reassembly of the Flip-Up Sight

Step	Description	Tool Used	Time Required	Difficulty: Connection Complexity	Difficulty: Force Complexity	Difficulty: User Complexity	Notes
1	Insert the Sight 1 Springs onto the Spring Holder. Then insert the Spring Holder into the Sight 1.	Hands	02:00	1	1	1
2	Insert the Sight 1 Attachment onto Sight 1 and screw in two screws.	Phillips Head Screwdriver	03:00	2	2	1
3	Insert the Sight 2 Springs onto the Spring Holder. Then insert the Spring Holder into Sight 2.	Hands	02:00	1	1	1
4	Insert the Sight 2 Attachment onto Sight 2 and screw in two screws.	Phillips Head Screwdriver	03:00	2	2	1
5	Insert the Sight Hinge onto the Hinge Attachment.	Hands	01:00	2	2	1
6	Place the spacer on top of the Hinge Attachment and screw in two screws.	Phillips Head Screwdriver	01:30	2	2	1
7	Place the two halves of the Sight Base together and screw in two screws.	Phillips Head Screwdriver	02:00	2	2	1
8	Insert Sight 1 and Sight 2 into the Sight Base and screw in two screws.	Phillips Head Screwdriver	02:00	2	2	1

Phase 4 : Reassembly of the Quick-Reload Clip

Phase 5 : Reassembly of the Barrel Extension

Challenges

Original Assembly

Assembly Versus Disassembly

Mechanism

Design Revisions

As the design team members assessed, disassembled, analyzed, and then reassembled the Nerf N-Strike Longstrike CS-6, they were able to fully understand the functionality and reasoning behind the design of the Nerf gun. From here, they were able to work together to recommend three design revisions to the original Nerf gun in order to improve a specific quality of the gun as well as address global, societal, economic, and/ or environment concerns. The following three redesigns of the Nerf gun are system level changes that have the potential to increase the desirability of the Nerf gun.

• Crank N-Nerf :

This first redesign is a mechanism change of the Nerf N-Strike Longstrike CS-6. It removes the linear cam and replaces it with a rack and pinion system. For this system revision, the Cocking Bolt would be replaced with a hand crank connected to a gear inside of the Nerf gun. This gear would then mesh with the added gears to the bottom of Air Chamber One. This can be seen below in the Crank N-Nerf figure which altered the original solid model of the Nerf gun to account for the new mechanism. This mechanism change would then alter the way the Nerf gun is used. Instead of pulling the cocking bolt back until it is locked in place, the hand crank would be turned to the user’s desired amount, as the gears mesh during the rotation of the crank. Then the dart would be released just as before by pressing the trigger. However, this new design will allow for a variety of range values of the dart depending on the amount of rotation of the crank as well as the potential for longer ranges as stronger spring constants should be able to be used with this new mechanism, though further testing as well as analysis is needed. Not only will this revision increase the performance of the Nerf gun, but it also has a societal factor, increasing the safety of the gun to the user as well. Before, with the Cocking Bolt, a child could easily pinch their fingers in the slots on the side of the Base where the Cocking Bolt was moved manual back or automatically forward when the trigger was pressed. With this new design, there will be no chance of pinched fingers as the crank will be located at a safe distance away from the Base and all of the other parts will be concealed inside the Base of the gun. This redesign will also decrease the realistic factor of the Nerf gun which is a global concern. It will no longer resemble an actual gun as it does now. This will allow the Nerf gun to be more acceptable in countries throughout the world, especially with the recent violence and terrorism going on. Finally, this revision will only cause a slight increase in the cost, if any. Injection molding will be used to create the new plastic parts, which is an economical process for large scale runs. Further research would be needed for exact cost projections but economically this redesign should not change the cost of the Nerf gun to the customer as a result of the new parts. This mechanism revision will cause the existing Nerf gun to be changed into a unique design unlike any current solutions today. This will then in turn increase the market or target audience for the Nerf gun. The Crank N-Nerf is a Nerf gun with longer, adjustable, and safer ranges for children and adults to play with.

• Nerf Semi-Automatic :

The second design revision changes the single shot Nerf gun into a semi-automatic. The current model of the Nerf N-Strike Longstrike CS-6 is equipped with a Quick-Reload Clip that holds six foam darts. After the clip is attached to the gun, the Cocking-Bolt is pulled back, which pushes a dart into Air Chamber One where the bullets rests until the trigger is pulled. The Cocking Bolt is then locked into place until the dart is released. For this system, only one dart can be loaded at a time into Air Chamber One and the Cocking Bolt must be pulled back between each shot, reloading only one dart into the Nerf gun. The design team’s revision however alters this system level single shooting of the Nerf gun. This redesign is the addition of a revolving chamber to the firing system of the Nerf gun, as shown below in the Revolving Chamber picture. By adding a revolving chamber, the same quantity of darts are at the user’s disposal; however, the revolving chamber will create a semi-automatic firing system. The user will no longer have to cock the gun back before each shot, but instead, the Nerf gun will only need to be loaded once with darts and then after each shot, the chamber of darts will automatically rotate allowing the gun to be ready to shoot. This chamber system will be lowered out of the Base to loaded and then fully enclosed in the Base during usage. For this system to be created the cocking bolt must be removed and the air chamber and piston system must be altered to allow for the automatic loading of the dart after each rotation of the chamber. The piston system must then be pulled pack and released automatically each time the trigger is pulled. This design revision will therefore impact the usage and performance of the Nerf gun. It also affects various economic and societal concerns. By adding the revolving chamber, the Nerf N-Strike Longstrike CS-6 will be able to shoot darts semi-automatically creating a unique Nerf gun. This Nerf gun not only has a new firing mechanism, but since the original barrel design was not changed, it also has a long firing range. The combination of these two factors will increase the desirability of the product as well as have the potential to expand its target audience. By adding a surprise addition, such as the revolving chamber, customer satisfaction increases which then increases sales as well as the company’s profits affecting economic concerns. Societal concerns are also addressed by this design revision. In the original design of the Nerf N-Strike Longstrike CS-6, the Cocking Bolt had slots on the side of the Base where it was manually pulled back or automatically released when the trigger was pressed, which caused a potential safety hazard as a child’s small fingers could easily be pinched in these slots. With this redesign however, these components are eliminated and the automatic cocking of the Nerf gun will take place inside of the Base of the gun as well the automatic rotation of the chamber. This greatly increases the safety of the Nerf gun to its users and the people who come into contact with the Nerf gun. This design revision, creating the Nerf Semi-Automatic, is a unique Nerf gun that takes firing and distance to new level for both children and adults.

• Bow & Dart Nerf :

The third and final recommended design revision by the design team is one that changes the way in which the force is applied to cock the Nerf gun. Currently the Nerf N-Strike Longstrike CS-6 is cocked by manually pulling the Cocking Bolt back until it locks into place. The dart is then released once the trigger is pressed and the Cocking Bolt is pushed, along with Air Chambers One and Two, back to its original position. This new design, however, removes the Shoulder Stock, the Cocking Bolt, and the Trigger from the original design. It also changes the slots on the sides of the Base to be located on the top and the bottom. Next, it changes the holes located on the sides of Air Chamber One to be located on the top and bottom of Air Chamber One aligned with the new slots on the Base. When Air Chamber One is then placed in the Base, these two holes should be at the start of the slots near the front of the Nerf gun. Then a new component is added to the design, a bow. The bow is half plastic on one side and half rubber band on the other. The plastic half of the bow fits through the holes located on Air Chamber One as well as stick out of the top and bottom slots. The two ends of the plastic section of the bow are then connected with specific rubber band along the outside back-end of the Nerf gun. A drawing of this can be seen in the Bow & Dart Nerf picture below. This redesign of the Nerf gun then changes how the gun is used. Instead of cocking the Cocking Bolt back, now with one hand holding the Quick-Reload Clip, the other hand pulls the rubber band back. By pulling the rubber band back, the plastic it is connected to moves back along the slot lines, and so does Air Chamber One, which the plastic part of the Bow runs through, along with Air Chamber Two. This allows the user to then pull back the rubber band as far as they desire, aim, and then release the rubber band while still holding the Quick-Reload Clip. When the rubber band is released, it has the same effect as pulling the trigger. The dart is pushed out of the Nerf gun and Air Chamber One and Two along with the Bow is pushed back to its original starting place. The reasoning behind this new design revision to the existing Nerf gun is due to specific consideration of materials. Since this new design eliminates many parts and only adds one, the materials used in the revision decrease. This will influence environmental concerns as less material is being used during the life-cycle of this new design. Also, an economic factor as a result of less material being used is that the cost of the Nerf gun will be less than before. This unique Nerf gun along with its ability to change its range will also increase desirability of the product as well as have the potential to increase its target audience. Finally, this design revision has the potential to support stronger spring constants which would increase the range of this product as well as increase its desirability even more. The Bow & Dart Nerf combines the traditional Nerf gun with a bow and arrow idea to create a redesign that is profitable and enjoyable to the targeted audience of children as well as adults.

Bow & Dart Nerf : The left section shows the original Nerf N-Strike Longstrike CS-6 with its Trigger, Shoulder Stock, Base, Barrel Extension, Cocking Bolt, Slots, Quick-Reload Clip, and Dart. On the other side, the third redesign of the Bow & Dart Nerf is shown. It has a Base, Barrel Extension, Bow, Quick-Reload Clip, and Dart.

Related Information

Main Page : Group 5 - Nerf N-Strike Longstrike CS-6

The Introduction : The Project Proposal

The Planning : *Gate 1: Project Planning

The Dissection : *Gate 2: Product Dissection

The Subsystems : *Gate 3: Product Analysis

The Conclusion : *Gate 5: Delivery