Revision as of 17:18, 26 October 2012

Preliminary Project Review

Cause for Corrective Action

Group 28 approached Gate 2 with enthusiasm and a well thought out plan to spread out the workload leave time for revision, in order to prevent what happened in Gate 1 and the Product Proposal. An outline/timeline was created to offer a visual representation of the estimated workload, but this may seem to be a reminder of deadlines more than anything, currently. The main purpose of Gate 2 was to demonstrate the ability dissect the product in an orderly manner and document that dissection process effectively. The week following the deadline of Gate 1, Group 28 held meeting during every scheduled time with at least 3 group members always present for these meeting. The missing group member usually had a time conflict with an important appointment, had difficulty managing his time, or had a communication breakdown among the rest of the group members. While missing meetings was heavily frowned upon, group members showed concern for missing progress updates or any information vital to completing assignments or projects. Also, Emphasis among all group members was put on attending group meeting to demonstrate the desire to increase progress on Gate 2. The meeting consisted of going over the anticipated schedule for Gate 2 and planning for any group assignments in the MAE 277 class. Our first meeting planned the most appropriate time for the Lead Disassembler and Data Compiler to dissect the product, and the tasks that would follow that dissection. The dissection was achieved with documentation that looked adequate prior to writing up the wiki. Unfortunately, other academic aspects and time mismanagement delayed the meeting that followed the dissection for about a week. The first meeting after the dissection, the lead disassembler and data complier provided feedback that the dissection was one small step from being complete, since an extra was necessary to accomplish the last step. With a reminder of the deadline, this last step for dissection was scheduled to be done as possible. nevertheless, the final week before the deadline was filled with additional dissection in order to satisfy the Gate requirements and a hurried typing of the wiki; once again mismanagement of time and an inability to abide to a schedule left Group 28 rushing to get Gate 2’s dissection documentation and technical report finished.

Overall, the proposed plans to complete Gate 2 were not followed properly, thus Group 28 encountered some ruts along the way. These problems need to be addressed at the next meeting in order to prevent this from occurring to on Gate 3, otherwise the quality of Group 28’s work will continue to decline. The poor performance on Gate 1(as well as actually re-doing it) will need to be re-iterated in order to grasp what Group 28 is doing wrong and reevaluate how to approach the project’s Work.

Product Dissection

Difficulty of Disassembly

The difficulty of the entire disassembly had numerous steps that required different tools and procedures to properly separate each sub components without causing damage.
Prior to outlining this process, we will provide a way to interpret the varying levels of difficulty through the use of a simple rating system.

Rating Scale:Difficulty of Procedure

Component/Part Inventory

Part/Component Name Additional Details Image Hopper (Inside) Hopper (Outside) Front Sight Front Sight Spring Front Sight Pin Ball Latch Barrel Front Bolt Linkage Arm Power Tube Valve Body Rear Bolt Rear Bolt Plug Drive Spring Tank Adaptor Nuts and Screws

Part/Component Name Additional Details Image Drive Pin Buffer O-Ring Elbow Latch Buffer O-Ring Front Grip Tank Adaptor Air Line Bolt Handle Trigger Trigger Spring Sear Sear Spring Trigger Guard Rear Sight

Tools used During Dissection

The Following tools were used during the dissection:

• Phillips head Screwdriver (small & medium sized)
• 1/8” Allen Wrench
• 11mm Wrench
• Physical Interaction with Hands

Outline of Disassembly

	Tool/Procedure	Difficulty	Description	Image
Step 1	Physical Interaction (Hands)	+	Unhook the hopper assembly by pressing downward on the front sight on the gun which acts as a button for releasing the hopper assembly. By pressing on the button, the hopper should be free to move about the hinge located on the right side of the marker.
Step 2	Phillips Head Screwdriver	++	Now that the hopper is removed from the main body, several screws removed will allow the hopper to separate into two halves along with a lid that was help together by those two halves.
Step 3	Physical Interaction (Hands)	+	Unscrew the barrel in the proper direction, and set the component aside. The barrel is a single, solid unit.
Step 4	1/8" Allen Wrench	++	Unscrew all the screws on the left face of the body. With these screws gone the casing should easily be removed with no resistance. This will also allow the ball latch and safety to easily be removed by hand.
Step 5	Physical Interaction (Hands)	+	Remove the front & rear sights, and the front hand grip. Without the case enclosing them, these components are removable by hand.
Step 6	Physical Interaction (Hands)	+	Remove the bolt assembly from the main chamber along with the end cap. None of these components are fixed or screwed in.
Step 7	Physical Interaction (Hands)	+	Remove trigger assembly, which consists of the trigger, trigger guard, trigger pins, trigger spring, sear and sear spring. These components are also not fixed to casing.
Step 8	1/8" Allen Wrench	++	Remove gas piston chamber by removing four screws which secure it.
Step 9	1/8" Allen Wrench	+++	Remove the two screws on the right side of the marker casing in order to remove the power tube and valve body. This was originally secure by Loctite adhesive.	[[ |200px]]
Step 10	11mm Wrench	++	Remove the hose from the valve body with the wrench.

Product Dissection Evaluation

Specific Difficulties

The dissection was carried out relatively well with the knowledge of Group 28's member who was most proficient with paintball markers. However, since so many small components were inside the casing they were prone to falling and being jostled if the marker was mishandled. After we noticed that screws and small parts were compiling during the dissection, we made sure to designate a separate area to clearly separate all the small for one another and prevent them from moving anywhere. Most steps to take apart the marker required only a simple Phillips head screwdriver or Allen Wrench and then only hands to easily remove the parts. Thus, the entire process was relatively easy until the screws that held the power tube and valve body to the marker casing. These screws were secured with an adhesive Loctite which did not allow for a normal removal; a great deal of force to be applies in order to loosen the screws. At first we had not recognized the red adhesive with those certain screws, but after removing the casing, we speculated that the manufacturers applied adhesive to these screws in particular to prevent the valve body from moving.

Overall Difficulty

The Tippmann 98 Custom paintball marker’s disassembly was easy for the most part and did not require great ingenuity to outline the necessary procedures for disassembly. This is most likely due to one of this product’s key feature: customizability. The Tippmann 98 custom is widely recognized for being a very standard model paintball marker that allows owners to customize and provide routine maintenance easily for the marker. With this is mind, dissecting the product for analysis is not much different than if an actual user wished to clean the marker. However, our analysis wishes to evaluate each individual part and the subsystems composed of those parts, while also acknowledging the particular arrangement and interaction of these components. While this marker represents a very user-friendly product, the manufacturer has clearly set a limitation disassembly at the valve body/power tube by making it exceedingly difficult to remove it from the maker casing; while the power tube and valve body can separate from the casing, the valve body is welded shut, so disassembly would not be an easily reversible process.

Product Sub-Systems

Image	Sub-System	Parts/Components
	Outer Casing	Marker Housing Halves
	Trigger System	Trigger & Trigger Spring Trigger Guard Sear & Sear Spring Dowel Pins
	Air Tank Storage System	Tank Adaptor Air Line
	Bolt System	Front Bolt Power Tube Valve Body Linkage Arm Rear Bolt Rear Bolt Plug Drive Spring Drive Pin Buffer O-Ring End Cap Bolt Handle
	Hopper System	Hopper (Plastic Shell and Lid) Feed Elbow

Analysis of Sub-systems

As the table above shows, the marker consists of four main sub-systems. Overall, each sub-system interacts with at least one other sub-system to allow for a fully functioning paintball marker. However, a further analysis of the sub-system and the interactions between sub-systems will reveal how the sub-system is useful to the entire product.

Marker Casing

The marker casing is probably the most important sub-system, since the outer casing physically connects to all the other systems.; without the marker casing to provide a point of support for the other sub-systems, the marker would demonstrate any useful function at all. The casing is not connected with any subsystem by way of signals, rather simple physical means such as screws and bolts. Also, since the marker casing is made of a strong metal material, the casing also serves to protect the certain sub-systems that reside within (bolt system and trigger system). As the trigger and bolt system consist of numerous, the protection of these components are most likely necessary for continued operation of the product. Another aspect of the casing is the front grip handle which is mainly serves to provide the user with better control of the marker.

Trigger System

The trigger system resides between the two halves of the marker casing. This trigger system is also connected to the bolt system though ways of signals. When the user pulls the trigger, a signal is sent to the bolt system for it to release the bolt and to export the mass. This is accomplished by the sear and sear spring which provide a medium for the trigger to send a signal, while physically interacting with the bolt system. If the trigger system was connected physically to the bolt system, the marker could fire unexpectedly and the user would not have complete control over the marker. User-regulated input to the bolt system allows for complete control by the user.

Air Tank Storage System

The air tank storage system is attached to the outer casing by screws and the bolt system by attaching the air line directly into the power tube. The tank adaptor is made to fit the standard CO2 tank size, since the energy source of the paintball is pneumatic in nature. When the tank is connected, the adaptor is opened and compressed gas is allowed into the system. From there, the air line supplies air to power tube; the gas is constant supplied but only the use of the trigger will allow bolt system to utilize the pressurize gas for pneumatic energy. Once the trigger is pulled, the gas applies a great amount of force to the paintball though the barrel, where the paintball is then projected. This system is efficient because only a certain amount of compressed gas is allowed out of the system at any one time, rather than letting gas escape while the marker is idle. The location of where the gas is temporarily stored is suited near the hopper subsystem, so when the gas is expelled through the barrel, the paintballs receive the majority of the pneumatic energy.

Bolt System

The bolt system resides within the outer casing and connects with the hopper system. The trigger system and air tank storage system provide a pneumatic energy and a signal which regulate how this sub-system functions. Since the bolt system interacts with each sub-system, many functions occur when the bolt system is used. When the bolt is pulled back via the bolt handle by the user, several actions should occur:

• A paintball will succumb to gravity and fall from the hopper into the chamber.
• Pneumatic energy derived from pressurized gas is allowed into the system from the air tank storage system .
• The user can now use the trigger system.

This function of the bolt system is clearly a result of the interaction between every other sub-system and allows for the primary objective of the paintball marker, projecting paintballs, to be accomplished.

Hopper System

The hopper system is physically mounted on the front end of the marker casing, adjacent to the front sight. Though mounted on the outside, an opening in the marker casing allows for an individual paintballs to enter the chamber where the bolt system resides. The hopper is mounted on the casing in a vertical, upright position that allows for paintballs to fall freely into the chamber and not be impeded by anything, provided that the bolt system in pulled back to allow paintballs to enter. The hopper also has an easy to open lid, that allows the user to supply ammunition with ease.

Sub-System Interactions

Connection and Interaction Diagram

Since the sub-system, the Marker Casing, is connected continuously to every other sub-system, the marker casing will be discussed with other sub-systems and not have its own section here.

The diagram illustrates the connections between the sub-systems and primarily the marker casing, and the interactions between all of the sub-systems. Square, colored boxes symbolize a distinct connection between the sub-system and marker casing, while arrows symbolize an energy, signal, or material transfer from a sub-system.

The Bolt System -

• No box is provided for the bolt system, since the entire sub-system resides within the marker casing.
• The red arrow symbolizes the transfer of pressurized gas, which leads into the bolt system.
• The yellow arrows denote that the bolt system is able to move back and forth. This is accomplished when the user pulls back the bolt handle, and then pulls the trigger.
• The orange arrow denotes the product of the the pressurized in the system along with the action of using the trigger after the bolt handle is pulled back. The pressurized gas is allowed to flow freely though the barrel of the marker and will produce a pneumatic energy transfer in this area.

The Hopper System -

• The hopper point of connection is pointed out but the violet boxes. This connection is primarily between the elbow latch and the front of the marker casing.
• The blue arrows represent the flow of paintballs into the chamber where the bolt chamber resides.
• The blue arrows end inside the chamber and meets with the orange arrow, which means that the paintballs will interact with the pneumatic energy produced by the bolt and air tank storage system. This will almost always result with the paintballs being propelled out through the barrel.
• The hopper is the only sub-system with only one area of connection, and is the easiest to removes compared among any components of the marker. As this particular hopper is the stock hopper, it can be replaced by third-party hoppers is the user wishes so. Thus, this sub-system is also the least important sub-system.
• The hopper provides the materials to complete the main function of this product; however, the action of feeding paintballs into the barrel is achievable by hand (single paintball feeding). Yet, this sub-system provides the user with the luxury of only having to reload in bulk periodically and more efficient results than feeding with a single hand.

The Air Tank Storage System -

• The primary points of connection of this sub-system to marker casing is at the bottom of the rear hand grip and in front of the trigger. However, at the latter of the connection areas, the sub-system goes through an opening in the casing and is directly connected to the bolt system, but since the bolt system is only held in place by the marker casing this does not mean anything significant.
• If a CO2 canister was attached to the right side of this system, a mass flow of air would enter the system. This is denoted by the red arrow. The red arrow follows the air line, which provides the means for the pressurized gas to flow into the bolt system.
• As regulated by the trigger and bolt systems, the air tank storage system is the primary source of energy in the product, while almost every other system provides only materials or signals in the entire process.

The Trigger System -

• The trigger system is housed mainly with in the marker casing, but the trigger and trigger guard are exposed for apparent reasons of being able to pull the trigger and preventing accidental trigger pulls.
• The light blue arrows symbolize the user’s action of pulling the trigger, which will interact with the bolt system and allow the bolt to carry out its actions.
• The trigger system is composed of mainly the trigger and the sear; the interaction between these two pieces is primarily between springs. As the trigger is pulled the spring moves the sear, and then the sear is what actually allows the bolt system to move. The trigger does not physically interact with the bolt system.
• The user controls the signal input that is carried out by the trigger system. Essentially, all other sub-systems are on standby until the user inputs the signal into this sub-system. The overall function of the product is regulated by this signal input.

Influence of G.S.E.E. Factor on Sub-Systems

Global -

• This marker is the epitome of customization in the world of paintball markers. The ability for users anywhere to disassemble, provide maintenance, and reassemble makes the entire product full of relatively simple sub-systems.
• Similar to the prior statement, completely new users to paintballs markers will probably not know how to use the product. However, little intuition is needed to recognize that the only the trigger, hopper, and air adapter are available to the user from the outside. A new user will find the layout of this product simple and intuitive towards firing paintballs.

Societal -

• The outer casing represents the support system of the entire product as every sub-system must function within or on it. Thus, the casing must be strong enough to withstand the forces exerted by the pressurized gases in the chamber and maintain its integrity if ever dropped.
• The hopper must also be durable enough to prevent paintballs from littering any nearby environment. While the effects of paintballs are temporary, other people may find any mess they create unpleasant
• The outer casing of the marker also does not resemble a standard issue firearm. The casing was designed to function as the body of something that acts like a firearm but will not confuse other people if they happen to see this product.

Environmental -

• The user monitors the expenditure of CO2 while the system is being used, rather than the gases being allowed to continuously flow out of the system.

Economic -

• The amount of part and components in each sub-system is very small in comparison to other similar products. Only having to create a few universal parts is more cost effective than having numerous parts; the manufacturer will be able to save much more money in the long run when they only have to create this certain set of parts.
• The primary source of energy for this product is pneumatic-based but more specifically pressurized CO2. The reliance of this simple, cheap, and easily-obtained gas only required a few simple sub-systems (air line & adapter) to properly transfer and regulate the gas. Simpler components will reduce design and production costs in the end.

Arrangement of Sub-Systems

As discussed in several other sections, the arrangement of this paintball marker is quite simple and intuitive to what the product is trying to achieve. The Hopper rests at the front of the casing and feeds the paintballs into the chamber. The particular place of where the paintballs enter is the exact spot where the pneumatic energy from the air tank storage system will interact with the paintball and propel it through the barrel. The Air tank storage system is attached to the bottom of the rear grip in order to prevent the canister from freely hanging from the marker. The connection of the air line hose to the bolt system does not impede the action of pulling the trigger or managing the hopper, which is as it should be. Since the hopper is located at the front the gun is top-heavy if paintballs are loaded, and the addition of the front grip allows the user to counteract the torque this weight causes on the front of the gun.