Group 28 - Gate 4 - Product Explanation - 2012
Gate 4 will analyze the reassembly of the Tippmann 98 Custom and the mechanisms that are within the product. Several design revisions at the system level of the product will also be presented to demonstrate how the product could be improved or modified to address certain factors.
Critical Project Review
Cause for Corrective Action
With the finalization of the project nearing, the group has gotten better at managing when each objective of the project needs to be done. The group uses each meeting to discuss what needs to be completed and distributes the workload evenly in order to create a fair workload among each member. If any group members needs help, the entire group will attempt to solve the problem rather than waiting for the problem to be solved right before the deadline. The group has also continued improving the previous gates in order to make the final presentation better.
The reassembly procedure begins with almost each component separate from any other component. The exceptions to this are the valve and the trigger, and elbow feed, which were not completely disassembled (for reasons of complexity/no need for disassembly).
No additional tools were needed to reassemble the product besides the tools originally used to disassemble the product. Those Tools were:
- 1/8” Allen Wrench
- Phillips head Screwdriver
Difficulty of Reassembly
The difficulty of the entire reassembly was relatively simple and straightforward, with the exception of a few procedures. The reassembly was completed with consideration to the product being fully functional and stable when completely put together.
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. Improper usage of tools or excessive force may result in minor to major damage of some components.
Rating Scale: Difficulty of Procedure
|Rating Symbol||Degree of Difficulty||Practical Example|
|+||Very Easy - Any task rated here can be accomplished almost immediately and with little effort. No physical exertion or advanced coordination is necessary.||Inserting Dowel into hole.|
|++||Normal - Any task rated here will involve a relatively simple procedure using coordination of the hand or use of simple tool(screwdriver, pliers, forceps, etc.). The ability to use a tool properly along with decent hand coordination is necessary.||Screwing in a screw with a screw driver.|
|+++||Moderate - Any task here will involve a procedure that requires prior knowledge on how to properly approach the certain scenario. Whether by hand or with multiple tools, these procedures will require aptitude and higher levels of coordination to disassemble the product in a timely manner. Reassembly in these certain procedures need to take into consideration how the components interacted with each other prior to disassembly, in order for the reassembly to be proper.||Having to insert a compressed spring into a space where other components are near.|
Original Assembly - At the end of reassembly, the product was identical to how it was when the group first received it. Anyone disassembling this product should be able to reassemble the product to its original state if they correctly do each procedure; disassembling the Valve is not recommended, since reassembly could be impossible unless advanced tools use.
Disassembly vs. Reassembly - The Reassembly and Disassembly are basically the same steps in reverse, with the exception of making sure each component is set in the right position. The disassembly was simply to take an inventory of each component and observe where the component was located in the product and with respect to other components. The reassembly was more exact and required precision in terms of replicating how the product looks assembled. There are no especially difficult steps that make either process very distinguishable from each other.
The main mechanism that appears in the product is the spring. More specifically, these are Compression Springs which are designed to compress (get shorter) as a load acts upon them, and consequently the spring provides a restoring force to when the load no longer acts upon them. These Compression Springs are present in three location of the product: the Trigger, Sear, and Rear Bolt System.
The Trigger Spring and Sear Spring function similarly as they both provide a restoring force to the component they act on, respectively.
- Trigger Spring – In the position where the Trigger Spring is located, the Trigger will compress the Trigger Spring when the user pulls it. When the user does not hold/squeeze the Trigger, the spring will naturally go back to its state of equilibrium by providing a force derived from its elastic potential energy. Overall, this spring ensures the Trigger goes back to the position where it started.
- Sear Spring – The Sear rests on top of the Sear Spring, and when the Trigger is pulled the Sear is raised on the left end, which lowers the right end and thusly compresses the Sear Spring. Exactly like the Trigger Spring, the Sear Spring restores the original position of the Sear.
- Drive Pin - The Drive Pin is located between the Rear Bolt/Plug and End Cap, and is compressed when the marker is in the cocked position. While the Drive Pin restores the original position of the Rear Bolt in the same manner of the two other springs, the Drive Pin contains a much larger elastic potential energy while being compressed. This elastic potential energy of this spring is used to propel the Rear Bolt forward which will then strike the Valve and allow paintballs to be fired.
Governing Equations -
- Hooke’s Law describes the force exerted by the spring; F = - kx, where F is the restoring force the spring exerts, x is the displacement of the spring from the equilibrium length, and k is the spring constant which is dependent on the properties of the spring.
- Elastic Potential Energy describes the amount of energy stored in the springs when compressed; U = ½ kΔx2, where x is the displacement of the spring from the equilibrium length and k is the spring constant which is dependent on the properties of the spring.
These design revision modify the product at the system level without modifying the component which the product is currently comprised of. They provide improvements and modification that allow the product to be used in more ways than previously before or improve the way the product functions.
- Rail Interface System - An R.I.S. can be placed on the top or sides of the gun in order to mount optics or flashlights. This has no effect on any subsystem of the marker but can give the user a distinct advantage over the rest of the competition. For example, a scope mounted to the top of the marker will allow the user to acquire and engage potential targets over a longer distance. A flashlight can be used for low light or nighttime uses of the paintball marker. The social effects of this are that it looks nicer and appeals to more people that want a customizable marker. The rails themselves do not offer an increase in performance but the attachments that can be put onto the rails can improve performance.
- Flatline Barrel - The user can remove the original barrel and replace it with a flatline barrel. This piece does not require any modification of the marker; it simply screws on like the original barrel. The barrel is designed to put backspin on the paintball. This improves the range and accuracy of the shots. The social effects is that it will appeal to people who want a better performing marker, and it can set the stage for further improvements and redesigns. Economically, a user can save money on paintballs because they will not have to fire as many rounds to hit their intended target. Also, this upgrade will only cost the user around $50.
- Stock - A stock can be attached to this marker. This will allow for greater comfort and stability for the user. The user has many different options to choose from as well. The stock can be a folding style, collapsible style, or a fixed style stock. Depending in the user’s preference each stock has benefits and weaknesses. For the folding stock, a weakness is the user is limited to the length it comes as. A benefit if this stock is that it can be folded to the side and be completely out of the way for close quarter encounters. A weakness of the collapsible stock is that it is not able to fold out of the way. A benefit is that it can be adjusted to the length the user prefers and it is generally more comfortable than a folding stock. For the fixed stock, a weakness is that it cannot be adjusted or moved at all. The benefit of having it is that it is generally comfortable and simple (no moving parts). The social factors of having a stock is that it will appeal to a wider audience that wants a more realistically looking and feeling paintball marker. Economically, this along with the previous design improvements is both affordable for the consumer and profitable for the manufacturer.