Gate 4: Reassembly and Explanation
Project Management: Critical Project Review
- Our group has been working on our time management which has been one of our greatest issues. Although we have increased our communication we still need to plan meeting times better and coordinate our schedules. The team manager has not taken an active role in setting up meeting times which means our group as a whole is taking a leadership role and pushing the groups work ethic in the right direction. Our team has been lacking in technical communications in our written reports and gates, even though the engineering side of the reports are solid. We have sought out help from the instructors, and have been told to use more direct language and answer the specific questions asked. We plan to utilize individuals outside of the group and teaching assistants, in order to identify the parts of our reports that lack clarity or succinct technical communication. We plan to meet multiple times before the final gate is due and work on our own in our free time in order to deal with timing issues.
Product Archaeology: Product Explanation
In order to define a meaningful scale we need to develop a relative scale with respect to Nerf guns on how difficult it is to reassemble them. There are three levels of difficulty that we defined based on our experience while reassembling the guns.
1) The least difficulty relatively. Reassembly only requires an alignment of the part in combination with the other part it may connect to. No tools were required and very little force and manipulation was required.
2) Medium difficulty relatively. Reassembly required connecting the part to 2 or more other parts and required some force and manipulation. Tools may be required.
3) Hardest difficulty relatively. Reassembly required reconnecting the part to multiple other parts and possibly fastening down that part in order to maintain its position. These parts require force to snap them or screw them into place, such as loading a high tension spring or a part that requires forcing an inclined plane into a clip slot.
Table 1: Speed Load 6 Reassembly
|Step Number||Picture||Description||Difficulty||Original Assembly||Challenges|
|1||In this step the barrel was reassembled and placed into casing. We took the cap and the barrel and put it on the slide. Next we put one end of the spring on the slide and one end in the spring cap. No screws were necessary to put these parts together. Lastly we placed the finished part into the case which also required no screws. No tools required.||1||The product was originally assembled by a machine.||This part wasn't too challenging. Some challenges we faced included getting the parts to fit together correctly. Since the parts weren't screwed together getting them to stay in the correct position was a little bit challenging.|
|2||The internal Magazine Track was easy to reassemble. The spring was placed into groves that hold it in place. The slide was snapped into place. The mechanism that helps load the gun was snapped into place then screwed onto the casing using a screwdriver.||2||Hands were used to assemble this originally.||Some challenges we faced here was snapping the slide back into the track. This step wasn't hard and not many challenges were faced.|
|3||The internal clip was screwed back onto the casing using a screwdriver. This was just a plastic covering.||2||A machine was used to assemble this in a factory.||Screwing the case on posed no challenges.|
|4||The trigger mechanism was put into place. The trigger fit right onto the case. The trigger spring was attached to the case and the trigger. The firing mechanism, which is the long blue piece above the trigger,was placed into the case just like the trigger. No tools required.||1||A machine was used to assemble the trigger in the gun casing as shown.||A big challenge with this step was connecting the blue trigger mechanism to the trigger and the barrel. This part is not screwed down so keeping it in place was difficult.|
|5||The main case was then screwed together using a screwdriver. The two halves were put together, one with the internal components, and one with the internal clip.||1||The screws were originally screwed in by a machine while originally assembled.||The only issue with this step was finding a screwdriver small enough to fit into the holes in the case.|
|6||The loading mechanism was screwed together with a screwdriver. A metal slide piece was screwed in place then screws holding the two plastic pieces were screwed together.||1||The screws were originally screwed in by a machine while originally assembled.||This step posed no challenges.|
|7||All the final touches were put on the gun. The rest of the screws were put in. We test fired the gun to see if it worked, and made sure everything was buttoned up. No tools required.||1||Hands were used to do this originally just as something is tested before it is shipped.||No challenges were encountered at this point.|
- The assembly that we had to do was much different than the dis assembly because reassembling gun required us to un-clip parts that are intended to be snapped into place but not removed. Disassembling the gun is much more difficult not because certain connections were permanent,but rather meant to be permanent and not intended to be removed. When being assembled in a factory the gun goes together in a uniform fashion along an assembly line, however removing the parts required much more dexterity and was not engineered to be taken apart.
- The assembly of this Speedload 6 was very similar to the dis assembly of the gun for every part. The Speed Six was assembled with non permanent connections and required few fasteners which leads to a less intensive assembly and dis assembly.In our assembly process it can be seen that we did not follow the same reverse process. The order does not completely matter in that, some of the components do not interact directly with each other so it can be assembled in a different way than the dis assembly.
Table 2: Vortex Vigilon Reassembly
|Step Number||Picture||Description||Difficulty||Original Assembly||Challenges|
|1||The barrel and the spring (white piece) snap together. The barrel itself is one big piece along with the spring. No tools required.||1||This was originally assembled by a machine.||Snapping the spring into place posed no challenges.|
|2||We continued to assemble the internal components by screwing on the trigger, the trigger bracket to the ammo holder. We screwed on the spinner device to the barrel. Lastly we screwed the ammo holder and trigger to the barrel. This required the use of a screwdriver. We had to fit the component to the barrel and secure them to the barrel.||3||This was assembled using a machine at first assembling.||This step posed many challenges. Our first challenge was finding where each part was fit together. There were a lot of small parts when we took it apart we lacked some details. Another challenge was finding where all the screw went. There were silver and black screws used on the internal components. This was a very difficult step.|
|3||In this step we screwed down the internal components onto the case using a screwdriver. We also had to put on the front plastic covering. This just added aesthetics of the gun. We also put the spring and an ammo piece into the ammo holder.This didn't require any screws we just had to connect the spring to the case.||3||This was done by a machine during original assembly.||This step had a lot of challenges. Finding out where the screws go to screw down the internal components was difficult. There were a lot of hidden spots where screws went. Since black and silver screws were used in this step, this step was quite difficult.|
|4||In this step we put the ammo holder cover on it and the release mechanism for the ammo holder cover. The release mechanism is the red piece above the trigger in figure 4. To put in the release mechanism we had to screw the piece down on the inside of the case using a screwdriver. The ammo holder cover was just placed in a track.||2||This was done using a machine in the factory.||The only difficulty with this step was screwing on the release lever was difficult once the internal components were in. Snapping the ammo door wasn't easy as well. It proved difficult to put in the track and make it slide.|
|5||To put the cocking mechanism on the gun we had to screw them together and make sure the pieces are on the track. We used a screwdriver to do this.||1||This was done by machinery.||This step posed no challenges.|
- When assembling the Vigilon Vortex it was found to be much harder than the actual disassemble of the gun. The whole gun was assembled in a factory and it was not meant to be taken apart. This posed problems for reassembling of the gun.
- The assembling and disassembling were different in the processes due to the complications of the gun. There were small pieces that we could not have control over and were hard to find the places in which they belonged.
The challenges we faced were:
- Permanent connections
- Small parts intricately connected
- Non permanent connection meant to be permanent
Design Revisions: System Level
Major Revision Clarification: The following design revisions are to work in conjunction with one another in order to increase the firing speed of the Speedload Six and in turn the overall performance. The dart redesign is a system level redesign due to the new interactions it will have with the firing mechanism and redesigned barrel.
The firing mechanism in the Speed Six should be replaced with the firing mechanism from the vortex; as shown as figure 1. As a system level revision the change of mechanisms would require a reconfiguration of the ammunition and barrel but I will focus on the firing mechanisms effect. The change in mechanism would increase the performance of the gun by propelling the dart further at a faster rate of speed. By removing the excess material required for a pneumatic system as shown in Figure2, the lever arm firing system will reduce plastic which will reduce the negative environmental impact. The main factor that would drive this revision would be economic. If the new mechanism were used it would be heavily advertised along with the redesigned ammunition in order to generate interest and sales. The novelty of a mechanical firing mechanism combined with a new dart type would drive sales and eventual profits. Since the new mechanism can be a scaled version of the Vortex mechanism it can be applied cheaply and even cut production cost due to its relative simplicity in comparison to the pneumatic assembly that is currently used. By increasing the muzzle velocity the target demographic would be very excited and interested in the redesigned model. The main concern of most Nerf consumers is the performance of the gun, especially the velocity and distance it can shoot, which would both be improved by the redesign. By incorporating an existing mechanism from a similarly priced model the price point of the Speed Six could be held constant.
One design revision that we would make to the Nerf Speed Six is to make the barrel one solid piece of plastic with openings in it to accommodate the new firing mechanism. There would be a slot in the bottom to allow the firing mechanism to come up and contact the dart. Another opening would be in the side to allow the dart to be put in the barrel and be fired. This would address an environmental concern with the reduced use of plastic and molds needed to make the barrel. This would also be an economic concern of price, the reduced plastic and manufacturing time would make it cheaper to produce and can bring down the overall price of the gun. The gun would still be focused at the same audience and aim for the same price point.
The ammunition would be revised by taking the classic Nerf dart or Dart Tag Dart (shown in Figure 3) and redesign the composition of the projectile while maintaining the classically identifiable look. The new dart would be made of a dense foam to make it more stiff and have a solid plastic core to give it the structural stability necessary to take the forces of the firing mechanisms lever arm. This redesign would be required to accept the new forces exerted on the dart and removal of the existing pneumatic mechanism. The dart would have longer flight times and velocity which will allow for further shooting of the dart. The new design revision would create competition within the Nerf line and generate more sales. By creating competition within their target demographic there would be a main economic result of increased sales and profit. By maintaining the price point for the Nerf guns and redesigning the ammunition, the company would be able to market this new gun competitively with their new Vortex line.