*Gate 2: Product Dissection

Introduction

For the next section in the design team’s project, the team members worked together in order to disassembly the Nerf N-Strike Longstrike CS-6 as well as analyze the subsystems that they found. The team first recorded- with visuals, video, and text- the step by step process that they took. This process broke the Nerf gun up into five disassembly phases: the Barrel Extension, the Quick-Reload Clip, the Flip-Up Sight, the Main Base, and the Shoulder Stock. These phases started from step one with the Nerf gun fully assembled to the final step with all of the components. Once that was complete, the design team worked together in order to fully analyze the subsystems that they found from the disassembly. The design team then supported their analysis with pictures, models, and tables. Finally, the team then analyzed their functionality as a group thus far as well as addressed their current challenges and previous performance. At this final step, in this section, of the design team’s project, the Nerf N-Strike Longstrike CS-6 is no longer a functioning Nerf gun, but a group of components that will soon be further analyzed.

Project Management: Preliminary Project Review

Cause for Corrective Action

In order to avoid late night cramming and insufficient information, Group 5 set up a plan in order to complete all tasks on time as well as to the best of their abilities. Between the due dates of Gate One, October eighth, and Gate Two, October twenty-sixth, the team had three schedule meetings. The original meeting plan was the following:

• 10/11 : Complete the dissection
• 10/18 : Finalize information and divide remaining tasks
• 10/25 : Combine, finish, and review Gate Two as well as start Gate Three

However, these meetings did not happen as planned. Due to conflicts among team members with exams as well as availability of the group during dissection times, the first meeting did not occur until October seventeenth. The actual plan that occurred was the following:

• 10/17 : Dissection process was started
• 10/18 : Dissection process was finished, remaining was work divided, and the extra assignment was addressed.

Note : At this meeting, the group’s plan went right, since they planned ahead and used their own tools to finish the dissecting. Also, Group 5 addressed the challenge that presented itself when an extra assignment was given. The team talked as a group on how to handle it and the compromise was an earlier meeting the following week as well as a second meeting later in the week.

• 10/22 : Combined, finished, and checked Gate Two. Then the extra assignment was started.

At this last meeting, the group talked about why their original plan did not work. The answer was that team meetings were scheduled without consideration of exams and in order to resolve this issue, each team member is going to bring their availability as well as exam schedule with them to the next meeting. Meeting times and dates will then be rearranged so that each member has time to study as well as work on the project. This should resolve the only challenge currently facing the group. Future conflicts will be handled the same, including talking, honesty, and compromises. The last thing discussed by the team was their performance on Gate One. The number grade they received was an eighty-seven and this was mainly due to little errors as well as forgotten information. The group decided to do two checks on the gates from now on before the submitted due date starting with Gate Two. Therefore, final revisions were made after class on October twenty-fourth. All in all, the design team’s management plan started poorly, but with cooperation among team members, the work was able to be fully completed in the end along and a plan was made to fix the current challenge on the design team.

Product Archaeology: Product Dissection

Disassembly

Product Dissection:

After assessing the work and management plans, Group 5 dissected the Nerf Longstrike CS-6. Throughout the dissection, a camera was used to photograph each step of the process, information and observations were recorded, and every part was cataloged. The purpose of this dissection was to give Group 5 a better understanding of the inner functions of the blaster and to see how the parts of the gun work together as a whole. The tools used and the step by step dissection process are described below.

Parts, Hardware, and Tools Used

Throughout the disassembly process, Group 5 cataloged of every part that was dissected from the Nerf Longstrike CS-6. A photograph was taken of each individual part and the material and quantity of each part was recorded. There were also 63 screws found and removed from the blaster during the process; the quantity of each size screw was recorded and can be found below.

Parts List:

Number	Part Name	Quantity	Material	Picture
1	Barrel Extension Base	1	Plastic
2	Barrel Protective Cover	2	Plastic
3	Barrel Tube	1	Plastic
4	Ring	1	Plastic
5	Sight Aid	1	Plastic
6	Spring Support 1	2	Plastic
7	Spring 1	2	Plastic/Steel
8	Knob	1	Plastic
9	Spring 2	1	Plastic/Steel
10	Quick-Reload Clip	1	Plastic
11	Spring 3	1	Steel	Note: The spring could not be removed from the Quick-Reload Clip.
12	Foam Dart	6	Foam/Plastic
13	Sight 1	1	Plastic
14	Sight 1 Attachment	1	Plastic
15	Spring Holder	2	Plastic
16	Sight 1 Springs	2	Steel
17	Sight 2	1	Plastic
18	Sight 2 Spring Holder	2	Plastic
19	Sight 2 Springs	2	Steel
20	Sight 2 Attachment	1	Plastic
21	Sight Base	2	Plastic
22	Spacer	1	Plastic
23	Sight Hinge	1	Plastic/Steel
24	Hinge Attachment	1	Plastic
25	Shoulder Stock	2	Plastic
26	Clip Storage	2	Plastic
27	Base Divider	1	Plastic
28	Main Base	2	Plastic
29	Clip Button	2	Plastic
30	Cocking Bolt	1	Plastic/Steel
31	Base Spacer	2	Plastic
32	Nozzle Divider	1	Plastic
33	Internal Spring 1 Connection	1	Plastic
34	Internal Spring 1	1	Steel
35	Trigger	1	Plastic/Steel
36	Divider 1	1	Plastic
37	Divider 2	1	Plastic
38	Divider 3	1	Plastic
39	Internal Spring 2 Connector	1	Plastic
40	Internal Spring 2	1	Steel
41	Internal Spring 3 Connector	1	Plastic
42	Internal Spring 3	1	Steel
43	Internal Spring 4 Connector	1	Plastic
44	Internal Spring 4	1	Steel
45	Internal Spring 5 Connector	1	Plastic
46	Internal Spring 5	1	Steel
47	Divider 4	1	Plastic
48	Internal Air Shaft Spring	1	Steel
49	Air Chamber 1	1	Plastic/Steel	Note: This component contains a non-removable nail.
50	Air Chamber 2	1	Plastic
51	Internal Air Shaft	1	Plastic
52	Base Connector 1	1	Plastic
53	Base Connector 2	1	Plastic
54	Internal Spacer	1	Plastic
55	Clip Hook	1	Plastic

Hardware List:

Number	Part Name	Quantity	Material	Picture
1	#10 x 3/8 screw	28	Steel
2	#10 x 9/16 screw	1	Steel
3	#10 x 5/8 screw	1	Steel
4	#10 x ½ screw	14	Steel
5	#10 x 7/8 screw	9	Steel
6	#10 x 7/16 screw	2	Steel
7	#5 x 3/16 screw	4	Steel
8	#5 x 7/16 screw	1	Steel
9	#20 x 3/8 screw	3	Steel
10	Nail	1	Steel

Tools Used:

The dissection process for the Nerf Longstrike CS-6 was simple and only required two tools in order to successfully complete the procedure. The two tools are listed below, as well as their functions throughout the disassembly process.

Tool Number	Tool Name	Function	Picture
1	Phillips Head Screwdriver	Unscrew the various screws found during dissection process.
2	Ruler	To measure the lengths of the screws found in the blaster, so that an accurate inventory could be made.

Disassembly Process Overview

The disassembly process for the Nerf Longstrike CS-6 was found to be very simple, taking only 2 hours to complete over the span of two days. Prior to beginning the disassembly process, Group 5 divided the dissection process into five phases; the disassembly of the barrel extension, the reload clip, the flip-up sight, the shoulder stock, and the base. The first three components disassembled were predicted to be the least challenging; therefore, those three were the first to be disassembled. On the first day, one hour was spent in the dissection lab, with Brian and Brianna working together on the actual disassembly of the blaster. To speed the process, Sarah was the designated recorded and wrote down each step to the process being carried out. Also, Brianna measured and cataloged the screws that were removed from the gun, as well as photographed pictures of every part that was removed. On the second day, one hour was spent dissecting the final two components; the shoulder stock and the base. The base proved to be the most challenging component to dismember throughout the process and the challenges that arose will be discussed later on in the report. Overall, the dissection process took 2 hours to successfully complete. The step by step procedure is listed below.

Ease of Disassembly

In order to safely, successfully, and efficiently take apart the Nerf Longstrike CS-6, each step of the disassembly process was recorded. The dissection 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 dissection which was predicted since each part of the Nerf gun has a different level of complexity. Group 5 created a number scale to rate the difficulty of each step listed as completed by an average person. The ease of the disassembly can be defined by the scale listed below.

Difficulty level-

1. Easy to Disassemble- Requires some planning, time or effort to fully disassemble the part. Yet it is still very manageable to remove the piece. An example of this could be the outer part of the barrel of the gun. Since it was just two pieces of plastic on either side of the barrel it was very easy to unscrew the product and get to the heart of the barrel.
2. Medium Difficulty to Disassemble- Requires more work and time to be put in than that of level 1, but is still manageable. Multiple attempts, or an extra person to complete the task, may be required for this step of the process. An example of this difficulty level is the inner screws of the barrel of the gun and stock. Although the screws are all visible and easy to find they are still fastened very tightly so secure the outer pieces properly.
3. Difficult to Disassemble- Requires a good amount of planning, work and time to finish the task. Also, could involve all the group members to work together doing different tasks to finish. An example of this is when Group 5 needed to separate the shell of the base of the blaster. This required us to work together to make a plan to successfully separate the two pieces without losing the parts contained inside.
4. Very Difficult to Disassemble- The part is not meant to be taken apart without damaging the product. An example of a part that cannot be disassembled is the piston located inside the base of the blaster. This part is attached to the base by adhesive that cannot be broken or heated, not allowing for removal of the part.

The Process

Note: The number in parenthesis corresponds to the component number in the parts list chart.

Phase 1: Disassembly of the Barrel

Step	Description	Tool Used	Time Required	Difficulty	Notes
1	Twist barrel extension (1) 90° to the left and slide out of place, detaching from base of blaster.	Hands	00:05	1
2	Unscrew six screws connecting blue barrel protective cover (1b) to the barrel.	Phillips Head Screwdriver	04:00	1
3	Remove the barrel protective covers (1b).	Hands	00:20	1
4	Unscrew 8 more screws found on orange base (1a) of the barrel.	Phillips Head Screwdriver	06:00	2	Some screws are very small and can be easily overlooked.
5	Flip up the grey sight aid (5).	Hands	00:05	1
6	Snap the orange barrel extension base (2) apart. This exposes the barrel tube (3).	Hands	00:10	1	Must be careful not to break the plastic when pulling apart.
7	Remove three springs (6 & 7).	Hands	00:25	1
8	Remove three screws.	Phillips Head Screwdriver	03:00	1
9	Remove grey sight aid (5).	Hands	00:05	1
10	Remove orange ring (4)	Hands	00:05	1

Phase 2: Disassembly of the Quick-Reload Clip

Step	Description	Tool Used	Time Required	Difficulty	Notes
1	Remove six foam darts (10) from clip.	Hands	01:30	1
2	Unscrew and remove 2 screws.	Phillips Head Screwdriver	02:00	1
3	Pull the clip apart (8).	Hands	00:25	4	The clip cannot be pulled apart; however, a spring (9) can be seen inside.

Phase 3: Disassembly of the Flip-Up Sight

Step	Description	Tool Used	Time Required	Difficulty	Notes
1	Remove 2 screws from the base of the sight (17).	Phillips Head Screwdriver	01:30	1
2	Detach sight 1 (11) and sight 2 (14).	Hands	00:30	1
3	Pull apart the blue sight base (17).	Hands	00:15	1
4	Unscrew and remove two screws from the gray hinge attachment (20). This then separates it from the sight hinge (19).	Phillips Head Screwdriver	04:00	1
5	Remove grey spacer (18).	Hands	00:10	1
6	Unscrew 2 screws from sight 1 (11).	Phillips Head Screwdriver	01:30	1
7	Remove blue sight 1 attachment (12).	Hands	00:15	1
8	Remove springs from sight 1 (13).	Hands	00:15	1
9	Unscrew 2 screws from sight 2 (14).	Phillips Head Screwdriver	01:30	1
10	Remove blue sight 2 attachment (16).	Hands	00:15	1
11	Remove springs from sight 2 (15).	Hands	00:25	1

Phase 4: Disassemble the Base

Step	Description	Tool Used	Time Required	Difficulty	Notes
1	Unscrew and remove 18 screws from the outer layer of the base (25).	Phillips Head Screwdriver	09:00	1
2	Remove the cocking bolt (21) by taking off one knob.	Phillips Head Screwdriver	03:00	2	This step required a great deal of strength in order to successfully remove the cocking bolt.
3	Using two people, unsnap the blue base into two halves (25). This then releases the base divider (24).	Hands	02:00	3	Be careful when unsnapping the base, there are small parts on the inside that may break free during the disassembly process.
4	Unscrew 10 screws on the inner part of base (25).	Phillips Head Screwdriver	06:00	1
5	Remove all springs and small plastic internal parts (26 - 38) of the Nerf gun.	Hands	08:00	1	Note: The internal air shaft (39), however, can not be disassembled and is a difficulty rating of four.
6	Remove Air Chamber 1, Air Chamber 2, and the Internal Air Shaft Spring from the Main Base.	Phillips Head Screwdriver	05:00	1
7	Remove the Internal Air Shaft Spring from Air Chamber 2.	Phillips Head Screwdriver	00:30	1
8	Remove the Air Chamber 2 from Air Chamber 1 .	Phillips Head Screwdriver	00:10	1	} Phase 5: Disassembly of Shoulder Stock Step Description Tool Used Time Required Difficulty Notes 1 Unscrew 10 screws from each side of the shoulder stock (22). Phillips Head Screwdriver 08:00 1 The 18 screws from the outer layer of the Base must first be unscrewed before the Shoulder Stock can be removed from the Base to be further disassembled. 2 Pull the shoulder stock apart (22). Hands 00:20 1 3 Unscrew three screws, on each half of the shoulder stock, which attach the extra clip holders (23) to stock. Phillips Head Screwdriver 06:00 1 4 Remove the extra clip holders (23). Hands 00:10 1 Intended Disassembly Throughout the dissection process, Group 5 was able to disassemble each component and break it down into smaller parts. The Nerf Longstrike CS-6 is a simple toy and was easy to disassemble; however, two parts of the blaster proved to be very difficult to break down further, allowing the group to label them as unable to disassemble. Internal Air Shaft: One piece of the Nerf gun that was not meant to be taken apart was the internal piston. The inside of the blaster where the firing mechanism and the inner barrel of the gun are located was found to be very difficult to disassemble during the dissection process. Group 5 believes the shooting of the Nerf dart comes with a certain amount of force from the spring and the force of the air. Due to this force, it is inferred that the makers of the gun used an adhesive to attach this mechanism to the inside base of the gun. Also, this glue forms a barrier around the piston, allowing for an increase in air pressure. After careful consideration and discussion amongst the group it was determined that using heat to melt the adhesive cannot be done, and if the piston is forcibly removed, after reassembly the air pressure created in the piston will have decrease thus decreasing the firing range of the toy gun. Picture: The photo shows the orange piston connected to the base of the Nerf gun by adhesive. This part of the product is not intended to be removed without damaging the gun. Quick-Reload Clip: Another part of the Nerf gun that was determined as not intended to be disassembled was the clip that holds the foam darts. Two screws were removed from the bottom of the clip; however, two plastic clips were found at the top of the clip, keeping the two shells of the clip connected and unable to be separated. After analyzing the clip it was determined that the plastic clips have been melted with the plastic of the base, making this part unable to be disassembled. If enough force is applied to pull the clip apart, the part can be disassembled further, but this cannot be done without breaking the component. Picture: The arrow in the photo points to the plastic clips that connect the two shells of the clip together. These clips cannot be separated, making this part of the product unable to be disassembled. Documentation of Connection of Subsystems Connection of Subsystems After completing the dissection process, Group 5 determined three main subsystems; the reload clip system, the base system, and the barrel system. Each subsystem is connected to one or more subsystems, aiding in the overall function of the system which is the flow of energy necessary to shoot a dart at a long distance with great accuracy. The reload clip shells are connected by the use of screws as well as well as plastics slots that have been melted together. The reload clip system is then connected to the base system by more plastic slots. The clip then snaps into place on the Nerf gun’s base. Now the foam bullets can be moved from the clip to the base system. The base system includes the cocking bolt, the trigger and the piston systems. The piston system is connected to the base by adhesive, while the trigger is connected by plastic tabs found inside the base. The cocking bolt is also connected by plastic knobs on each side of a metal rod that allow the cocking bolt to be moved on the base. The dart enters the base where human energy, from the sliding of the cocking bolt, is converted to mechanical translational energy. The trigger is then pressed by imported energy from a human finger, which then causes the mechanical translational energy to be converted to pneumatic energy. Finally, the barrel system is needed to complete the overall function. Each shell of the barrel extension is connected to one another by screws. The barrel extension is then connected to the base by plastic slots in which the barrel can connect by lining up the slots and twisting it onto the base. At this connection point, pneumatic energy is transferred to the dart, forcing the dart through the barrel and allowing it to be shot at a long distance with great accuracy. The sight system and the shoulder stock system are also connected to the base of the Nerf gun; however, they do play a role in the overall function of the product. The shells of the sight are connected by screws to keep the sight together. The sight can then be connected to the base by plastic slots on the top of the gun. The sight does not aid in the transfer of energy, but it is a signal that aids in the accuracy of the firing of the gun. Also, the shells of the shoulder stock can be connected to one another by screws and is connected in the same way to the base of the gun. The plastic clip holders are connected to the stock by screws and allow for provision in the system by storing the spare clips filled with darts. The subsystems described can be found in the table below along with their functions. The energy and mass flows described can be found as well. Subsystem Number Name Function Picture 1 Reload Clip System Transfer mass into base system. 2 Base System Overall function is to use human energy as input and pneumatic energy as output. 2a Cocking Bolt System Convert human energy into mechanical translational energy. 2b Trigger System Human energy used to release mechanical translational energy. 2c Piston System Convert mechanical translational energy to pneumatic energy. 3 Barrel System Transfer pneumatic energy to dart. 4 Sight System Visual status: positioning if the gun. 5 Shoulder Stock System Provision: stores the spare clips filled with darts. Functional Model: These connections are made so that the main function of shooting a dart at a long distance with great accuracy can be performed by the Nerf gun. These subsystems must input energy and mass in order for the necessary output energy and mass to be produced to allow for the main function to be produced. The screws on each component keep the product together to aid in the transfer of energy, as well as the adhesive, and plastic slots found throughout the product. Connection Implementation Not only are the subsystems as well as the reason for their specific connections points important, but how the connections are implemented play an extremely important role in the design and functionality of the Nerf Longstrike CS-6 as well. This Nerf gun has three main connection types, two of which are non-permanent connections while the other is used as a barrier. The barrier, or permanent connection, in the Nerf gun is a joint that is not intended to be disassembled and in this Nerf gun is a glue adhesive that is located in slots which connect the piston to the back of the base. It is designed in this way to allow a direct and therefore more efficient transfer of energy during normal usage. The other two connections, which are non-permanent joints that are used within the Nerf gun and are easily disassembled, are screws and slots. The screws used are all standard sizes while the slots are used so that subsystems as well as components can easily fit together without any extra connection points necessary[1]. The reason for this specific combination of three as connections types for the Nerf gun has to do with four main factors influencing the design: The first factor affecting the design is a global factor considering safety standards all around the world. In order for the Nerf gun to be sold in different countries, for the most part, it has to pass safety standards which differ from country to country. These three simple connection types meet these safety standards which allows for a greater market for the product. Another factor for the Nerf gun is an economic factor considering the economy that potential buyers are dealing with. Due to this as well as the variety of Nerf guns created, these connection types are used because they are inexpensive and can be mass produced. This allows for a smaller cost to the potential buyer and a larger profit for the producer, which in this case is Hasbro. A third factor is society, or societal factors, considering the safety of the user as well as those who come into contact with the Nerf gun. These three connections are used because they allow for no harm to come to the user. [Note the glue adhesive is located in the most inner-section of the Nerf gun]. This factor is comparable to using nails instead of screws. This would be an improper design choice for the safety of the people as well as objects coming into contact with the Nerf gun. The final factor affecting the original design of the Nerf gun is that of the environment. These three connections are relative strong with a long performance span. This limits the potential replacement of these parts which in turn decreases its environmental impact. These three connections, screws, slots, and a glue adhesive, were chosen for very specific reasons allowing for a better design. They were also influenced by performance. They were chosen because they were strong enough to withstand normal usage and complete their functionality, especially with the promised range of the dart. A connection needs to be chosen that allows the product to perform its given nature for the longest amount of time. Together, all of these factors allowed for the design of a Nerf gun involving screws, slots, and a glue adhesive to connect its subsystems. Arrangement of the Subsystems The arrangement of the subsystems are illustrated in the functional model and connection of subsystems chart. The reload clip, base, and barrel subsystems must be connected in series in order to complete the overall function of the system. However there are other subsystems with sub-functions that can be connected in parallel to the main system. The performance of these sub-functions is unrelated to the main function. For example, the sight system, which is connected in parallel to the base system, can be attached to the base at any time throughout the system. Its function of creating a more accurate shot when the gun is fired is not directly connected to the energy and mass flow necessary to fire the dart. The shoulder stock system also is in parallel with the main base system. The storage of spare darts connected to the shoulder stock is not directly related to shooting the dart from the gun. On the other hand, the main reload clip system must be directly connected to the base system which contains the subsystems of the cocking bolt, trigger and piston. This series connection allows energy and mass to flow through the gun to perform the main function of shooting the foam dart from the barrel system. If the base system were adjacent to the reload clip system, then no dart could enter the base and the main function could not be successfully performed. Challenges: Although the dissection process was found to be very simple, a few challenges presented themselves during the process. There were three main challenges that Group 5 was faced with, which had to be addressed and solved. Separating the shell of the clip: When the reload clip was dissected, it was originally believed that two screws could be removed and then the separation of the shells would be easy. However, when Group 5 first attempted to pull the shells apart, they could not separate. No amount of strength and no tool were found that would aid in the separation of the shells. After 30 minutes of examining the clip, Group 5 determined the part to be unable to be disassembled. Separating the body of the base: The next challenge the group was faced with was separating the base of the Nerf blaster. If the two shells were simply pulled apart, then the grouped risked having the small internal parts fall out of the base, leaving the proper location of each part unknown. Therefore two people were needed for this part of the procedure where they slowly and gently unsnapped/pulled the parts from one another. When the two shells were finally separated, a few stray parts fell from the gun. The group then had to slowly analyze each space inside the gun to figure out where each individual piece fit. Knowing where every part goes will aid in the reassembly process. Removal of the cocking bolt: The last challenge that Group 5 faced was the disassembly of the cocking bolt from the base of the Nerf gun. The cocking bolt, part number twenty-one in the parts list stated above, consists of a steel metal rod with two plastic knobs on each end. This part of the gun needed to be taken apart in order for the base of the gun to be disassembled properly. A great deal of strength was applied to pull the orange knob off the rod, but that wasn't enough. The group member then used his pressure along with the assistance of the Phillips head screwdriver to finally prop it from the rod. After examination and consistent strength, the part was able to be disassembled; only creating a minor speed bump in the disassembly process. Related Information Main Page : Group 5 - Nerf N-Strike Longstrike CS-6 The Introduction : The Project Proposal The Planning : *Gate 1: Project Planning The Subsystems : *Gate 3: Product Analysis The Reassembly : *Gate 4: Product Explanation The Conclusion : *Gate 5: Delivery Citation [1] Bo'sun Supplies,Co.(n.d.). Screw Sizes and Thread. Retrieved October 21,2012, from http://www.bosunsupplies.com/ScrewSizesThreads.cfm