Group 21 - Jeep® Wrangler Power Wheels 1 - Gate 4
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Project Management: Critical Project Review
With only a short time before the final submission of the project, Group 21 has worked out almost all of its kinks. The problems that the group has resolved prior to this Gate can be viewed in the Project Management sections of the previous gates. There is still one issue that the group still needs to resolve that grows more and more important as the presentation date approaches. No members of the group feel completely comfortable with speaking in front of a large group. Since the presentation portion of the project is this heavily weighted, it is creating stress for the individuals of the group. When asked the reason for the lack of confidence, most members explained that they feared they would be unable to convey their knowledge for the product in the way the instructors expect. In addition to that, the fear of receiving a obscure question that would leave a presenter stumped at the podium.
Unfortunately, stage fright is not a simple problem that can be resolved a week before the project presentation. However, implementing proper preparation can instill the confidence necessary for a quality presentation. Making sure that every point in the presentation can be fully backed up with data and rationale. Also preparing for possible questions that other students and instructors could possibly ask will show how much Group 21 understands the product. This ability to concisely and coherently convey ideas and concepts to the public is an important skill for an engineer.
Product Archaeology: Product Explanation
Reassembly Challenges
The only tools used in the reassembly process were the P2 Phillips Head Screwdriver, the 1/8 Flathead Screwdriver, and the Assembly Wrench.
In order to define the difficulty of reassembly scale, the condition of each part after the dissection must be considered, which is done in Figure 1. If the part was damaged it automatically makes the reassembly more difficult because the part possibly might not be able to be used, or it may inhibit the original purpose of the vehicle. If a tool is required in the reassembly step and it is substantially different from the dissection, the process is considered to be more difficult than a process that requires no tools and follows very similar steps as the dissection.
Figure 1: Reassembly Complexity Scale
During the reassembly of the product the major challenge dealt with the metal retainer and black plastic cap. These two parts were used to hold together the wheels and the top of the front axle. The reason for this challenge was because during the disassembly of the product these parts had to be forced off and were bent and warped during this. These parts were not meant to be removed by the consumer and therefore after the removal it was difficult to put back. However, we did force these components back on the wheels but they were not as sturdy as they were originally. We would not recommend this product to be used because of the weak connections at the front axle and the wheel. The metal retainer can be seen in Figure 2.
Figure 2: .354 Retainer
When the product is received by the consumer the only parts that come assembled are the wheels and the axles onto the body of the Jeep. This is most likely done by an automated assembly process which takes the parts after they are machined and assembles them. The other parts which come assembled are the motor, wires and gearbox. This would always come assembled because Fisher Price would not want the consumer to have to attempt to assemble difficult portions of the Jeep, especially when electricity and moving parts are involved. When the axle was attached to the Jeep with the wheels on it, a metal retainer is placed to prevent the axle from being removed. From here the consumer is required to assemble the rest of the product. This requires simple tools and knowledge. By following the steps outlined in the manual any adult could complete the assembly in under an hour.
Overall the assembly and disassembly were very similar. The same tools and amount of time was spent on almost all of the steps. The main difference was that getting the traction bands back onto the wheels took more time than getting them off. Also the metal retainer and plastic caps were damaged during removal and this made it more difficult to put the product back together. However, the overall time spent on the assembly process was much less than the disassembly process because we were already very familiar with the components and the systems.
Product Reassembly
Motor and Gearbox
1-Medium sized gear (gear 2): Slide onto the vertical axis in the middle of the bottom part of the gearbox, with the small part that is attached to the gear on top (facing up). Difficulty Rating: 1
2-Largest gear (gear 1): Place in the largest side of the gearbox with the smaller part on top (facing up), making sure the gears fit together. Difficulty Rating: 1
3-Smallest gear (gear 3): Slide onto the vertical axis in the smaller end of the gearbox, with the small part that is attached to the gear on the bottom (facing down). Difficulty Rating: 1
4-Top of gearbox: Place on top of the gearbox bottom, making sure the ends match up so the top slides onto the bottom. Difficulty Rating: 1
5-Flip the gearbox over so the bottom is facing up, holding onto it so it does not fall apart. Place 2 screws in the and screw them in with a 1/8 flathead screwdriver. Difficulty Rating: 1
6-Flip the gearbox over again, so the top is facing up. Place two 1.25” screws in the smaller end of the gearbox (the ends of the screws will stick out of the bottom) Difficulty Rating: 1
7-Stick the gear attached to one end of the motor into the bottom of the gearbox. The two 1.25” screws will go into holes in the motor on the end with the gear, so the motor will be attached to the gearbox. Difficulty Rating: 1
8-Put the black plastic motor case around the motor and snap it shut. The end with the hole goes around the end of the motor that has the gear attached to it. The wires attached to the motor go out of the motor case through the small square opening. This opening is on the side of the case that snaps together (not the hinged side). Difficulty Rating: 1
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Rear Axle Assembly
9-Take the gray body of the Jeep. Place it on a surface (like a table) and stand behind it, so you are looking in the direction the driver would be looking in. Make a note of which side of the Jeep is on the left and which is on the right. Now flip the body of the Jeep upside down, so you are looking at the bottom, remembering which sides were designated left and right. Difficulty Rating: 1
10-Take the two white plastic triangular spacers (axle protectors). Slide them into the gray parts that stick out in the back end on the bottom of the body. Make sure the holes of the spacers line up with the holes of the body. The longest edge of each spacer should be parallel to the gray part it goes into. Difficulty Rating: 2
11- Slide the back axle (a straight metal rod) into the holes that go through the gray parts and the white spacers. Make sure there is an even amount of the axle sticking out of each end. On the back left side, first slide the black cylinder onto the axle. Difficulty Rating: 1 Slide the white cylinder on.
12- Take one of the wheels and slide it onto the axle. The side with the “bolts” should be facing away from the vehicle. Difficulty Rating: 1
13- Slide the black cone-shaped “wheel bushing” onto the axle, with the smaller end fitting into the wheel. Difficulty Rating: 1
14- Slide the metal bearing (looks like a metal ring) onto the axle. This piece does not fit exactly as it did originally. During disassembly that piece had to be pried off, and was bent and misshapen in the process. Difficulty Rating: 4
15- Put the black plastic cap onto the axle. You should be at the end of the axle now. The cap will snap into the hole in the wheel. This piece also had to be pried off during disassembly, so it is dented and does not fit exactly as it did before. Difficulty Rating: 3
16- Snap the red plastic cap into the wheel over the black cap. The rounded part of the red cap will be sticking out of the wheel. This part requires a hammer (or a similar tool) to hit it until it snaps back into place. It is too difficult to push back in with just your hand. Difficulty Rating: 2
17-Take the black rubbery ring (“traction band”) and fit it onto the wheel. It will be centered around the wheel when it is on all the way. It is somewhat difficult to put on, but can be done without the use of any tools. Difficulty Rating: 3
18-Now go to the back right side. Slide the gearbox onto the axle. The flat side of the gearbox goes against the body of the Jeep, with the part with the motor attached closer to the front of the Jeep. Difficulty Rating: 2
19- Slide a wheel onto the axle. The part of the gearbox that sticks out goes into the wheel. Difficulty Rating: 1
20- Slide the rest of the parts onto the axle. (See instructions for the previous wheel, starting with step 13 and ending with step 17). Difficulty Rating: 1
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Wires
21- Start at the motor. Hold the wires coming out of the black motor case, and follow them away from the case until you get to a white plastic case. This case slides into the square opening in the center of the body of the Jeep. The wires stick out of the opening. Difficulty Rating: 2
22- Continue along the part that has blue, black, and white wires. The white plastic case attached to them goes through the vertical rectangular opening on the right side. Difficulty Rating: 2
23 - Go back to the first plastic case and continue along the part that has black and white wires. The black plastic case attached to them goes into the small opening below the previous opening. Difficulty Rating: 2
24 - Now go back to the motor case and follow the wires again. When you get to the smaller white plastic “clips” that hold the wires together and have a hole on the end, place one of the smallest screws through the hole and screw it into a gray cylinder sticking out of the body. There will be three of these clips. Difficulty Rating: 2
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Front Axle
25 - Take the front axle. Slide a washer onto each end. Then put the same wheel assembly components on as in the rear wheels (starting with step 13 and ending with step 17). Difficulty Rating: 1
26 - Hold the axle with the shorter metal rods pointing down. Look at the white plastic parts attached to the axle. Make sure the long flat part is facing away from you. Stand at the front of the Jeep, with the body still upside down. The 2 shorter metal rods go into the 2 holes that are at the top of cone-shaped pieces sticking out of the body. Difficulty Rating: 2
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Steering Assembly
27- Take the steering column (the metal rod with the bent part at the end). Put the long straight part through the hole in the body of the Jeep that is close to the front end. The column will be at an angle. Difficulty Rating: 2
28- Lift the front axle slightly to put the steering column through the hole in the front axle. The short end of the column (at the end of the bent part, that has threads on it) is the part that goes through the hole. Difficulty Rating: 2
29- Using a wrench, twist a 3/16” locknut onto the end of the steering column, so the column becomes attached to the front axle. Difficulty Rating: 2
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Body
30- Flip the body of the Jeep over so it is right side up. Difficulty Rating: 1
31- Find the white plastic casing on the wires that stick out of the center of the Jeep. Plug the forward/reverse button (white) into the casing. Difficulty Rating: 2
32- Find the white plastic casing on the right side of the center hollow part of the body (where the driver would sit). Plug the foot pedal into this casing. Difficulty Rating: 2
33- Look in the hollow part that is closest to the front of the Jeep on top. The 2 short metal rods that attached to the front axle should be visible. Put a black plastic cone (like the ones used in the wheels) on each rod, with the smallest end of the cone pointing down. Difficulty Rating: 2
34- Put a metal bearing and a small black plastic cap on each rod. These parts are like the parts used in the wheels, and were also damaged during disassembly. Difficulty Rating: 4
35- Place the battery into the hollow part between the parts where the rods are. Plug the battery into the black casing attached to the wires. Difficulty Rating: 1
36- Place the battery retainer (small gray plastic cover) over the battery compartment, with the circle that on it closest to the dash. Difficulty Rating: 2 Connect the yellow “spark plugs” to the holes in the battery retainer.
37- Using a P2 Phillips head screwdriver, screw one #8x1” screw through each side of the battery retainer. Difficulty Rating: 2
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Dash Board
38- Take the dashboard and place it onto the top of the Jeep behind the battery compartment. There is a part sticking out on the top of the Jeep on each side that the dashboard goes on top of. Make sure the steering column goes through the hole in the dash.
39- Take the red activity panel (with the lever and knobs) and place it on the right side of the dash. Put the bottom pegs into the dash and screw two #6 x ½” screws (using a P2 Phillips head screwdriver) into the top of the panel.
40- Snap the red instrument panel into the left side of the dash. Difficulty Rating: 2
41- Put the windshield and frame together. The part of the windshield that sticks out goes into the frame (from the back of the frame). Difficulty Rating: 2
42- Using a P2 Phillips head screwdriver, screw five #6 x ½” screws into the windshield and frame (from the back). Difficulty Rating: 1
43- Put the windshield and frame onto the body of the Jeep, with the frame facing forward and the “hinges” closest to the body. Difficulty Rating: 2
44- Using a P2 Phillips head screwdriver, screw two #8 x 1” screws into each hinge that connects the windshield frame to the body (4 screws in total). Difficulty Rating: 2
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Body (continued)
45- Go to the front of the Jeep. Slide the grille into the front, with the “headlights” facing forward. Difficulty Rating: 1
46- Put the tabs attached to the hood into the slots on the body of the Jeep (close to the windshield). Lower the hood so it covers the battery compartment. Difficulty Rating: 1
47- Lift the red hinges on the body and place them into the slots on the hood. Difficulty Rating: 1
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Steering Wheel
48- Put the top and bottom of the steering wheel together, lining up the plastic parts. Screw four #6 x ½” screws through the bottom of the steering wheel. The bottom is the side with the part sticking out. Difficulty Rating: 2
49- Slide the steering wheel onto the steering column with the bottom facing down. Difficulty Rating: 2
50- Using a wrench, twist a 3/16” locknut onto the steering column. Difficulty Rating: 2
51- Place the black steering wheel cap over the locknut, in the center of the steering wheel. Screw two #8 x 1” screws into the steering wheel through the cap. Difficulty Rating: 3
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Design Revisions
Second Gear Box
Mounting of another small electric motor on the other wheel will give the Jeep an increased power output, giving the vehicle a faster velocity. This change will be more appealing to the older users of this toy. This would greatly impact the economic factor of the Jeep. Adding the necessary parts will result in an 80-dollar price increase. The parts needed include a 12V battery, an additional motor, secondary gearbox, wiring, and mounting components. The Jeep will be marketed along with more luxurious Power Wheels priced at $300 and over, but this product can still be sold at a slightly lower price, allowing more units to be sold. This increase in price could very well turn some consumers off of the product, but the changes may give others even more of an incentive to buy. On a societal level this product is directed towards small children from ages 1 and a half to 4 but with the possibility of a faster more “thrilling” ride this revised product could be sold to older children. However, to compensate for the added weight due to older children driving the Jeep, the body of the vehicle will have to be stronger. The battery compartment in the front will also need to be larger to hold the new battery. The entire Jeep will most likely need to be made larger to balance out the changes in the front and to hold an older child.
Stock price point: $200.00 [1]
Price increases:
-Secondary motor : $ 15-20 [2]
-Replacement battery: $50 [3]
-Secondary gearbox: $30 [4]
With removal of the 6V battery, Fisher Price is saving roughly $20 thus the net increase in price point is $80.
Global: The global issue of this change is virtually non existent.
Societal: The addition of power and speed will help market this product to older children.
Economic: The price does significantly increase but it can still be marketed at a lower price than comparable models.
Environmental: More parts need to be manufactured, so the environmental footprint will be larger. Manufacturing more plastic parts will increase the amount of pollution associated with the creation, usable life span, and the disposal of the product.
Changes associated with the new motor
-As seen in figure 1 the current housing for the 6V battery will not hold a new larger 12 battery. During the manufacturing process the slot for the battery was only made to accommodate a 5.5x4.5x5.5 inch battery.
-A new motor gearbox will have to be installed to the rear axle, like the set-up shown in Figure 2.
Figure 1: Battery Housing
Figure 2: Dual Gear Boxes on Rear Axle
Steering Wheel Impact Cushion
Placing a soft cushion in front of the steering wheel provides optimal safety for the child. As a cushion is well known for its shock absorption, we believe that such addition to the design will drastically decrease the chance of children getting injured during impact.
Economically, the cost a cushion with the size 15 x 15 x 3 in depth, width and thickness respectively range between 5 dollars to 30 dollars, depending on its quality/hardness. Instead of risking the safety of a child and possibly spending 50 dollars on medical bills, a 5 dollar addition to a product is definitely the best deal every parents could afford. Cushions and foams are mainly made out of polyester polyurethane. This polymer product can be decomposed into isocyanates, carbon monoxide, nitrogen oxides, and hydrogen cyanide upon contact with flame. Even though minimal, these chemical still causes harm to the environment thus it is advisable to keep the cushion away from flame. Such modifications to the design will bring slightly further burden to current petroleum industries, however being able to ensure the safety of the user, the benefit outshines the disadvantage altogether.
Global: The global issue of this change is virtually non existent.
Societal: Safety guaranteed, decreasing the risks of injury to children upon impact.
Economic: Additional cost of 5~30 dollars for every cushion included into the model.
Environmental: Petroleum production tend to increase as this is one of the ingredients to create polyester; isocyanates, carbon monoxide, nitrogen oxides, and hydrogen cyanide would be released into the air upon the disposal of the product.
Changes associated with the addition of cushion: As seen in the picture, there’s a space in the middle of the steering wheel that can be utilized fully. The size of the hole is smaller than the dimension mentioned for the cushion pricing, thus the charges for new cushion are to be suspect to be lesser.
Variant Speeds
Second speed added to Jeep, allowing the vehicle to move at a maximum speed of 5 mph and a minimum speed of 2½ mph. The reverse function would operate at the minimum speed.
System Changes:
1. The current 6-volt battery would need to be replaced with 12-volt battery to allow the vehicle to reach the maximum speed of 5 mph.
2. Dimensions of battery increase from 3.5” x 4.75” x 3.5” to a possible 4.5” x 5.88” x 5.63” – this would require an increase in the size of the front end, where the battery is located. It would be beneficial to find the smallest 12-volt battery possible so that the change in the front end could be minimized.
3. The motor would not change; it is already a 12-volt motor.
4. A control would need to be added so the user could select the desired speed. The forward/reverse control would be modified so that it had a reverse button, and the two buttons labeled speed 1 and speed 2. The location of the forward/reverse control would remain the same, except the size of the button, and consequently the size of the hole the button fits in would change.
5. Other Power Wheels vehicles that can reach speeds up to 5 mph are restricted to the ages 4 to 6. So it would be recommended that children under 4 do use the higher gear. To address this issue an optional protective cover for speed 2 would be included so the parents could restrict the younger users from going faster than recommended. The protector would be fastened to the vehicle by two extra screws that would be included. This would broaden the target age group to 1 ½ to 4 years old to 1 ½ to 6 years old, which would hopefully help cover the cost of the improvements made to the Jeep.
6. The average weight of a 6 year old is approximately 47 pounds, which does not exceed the current maximum weight of 50 pounds. However to ensure the product does not fail it would be beneficial to look into reinforcing the frame of the car, and possibly other parts of the vehicle through force analysis.
7. The added speed control would call for more wiring to the forward/reverse control. The additional wiring would most likely not significantly impact the cost of the vehicle.
4 Factors:
Global Concerns- The change in the maximum speed of the Power Wheels Jeep would not alter the global concerns that the Jeep had prior to the changes. The Jeep is not meant for sale outside of English speaking areas due to the fact that all of the decals have English writing on them, and more importantly the entire Owner’s Manual is completely in English.
Economic Concerns-The cost of the battery would increase based on the prices that retailers are selling the 12-volt batteries at compared to the prices of the 6-volt batteries. Their prices range from 40 – 60 dollars for the 12-volt, while the 6-volt battery ranges in price from 15 – 40 dollars. The extra button, wiring, speed protective cover, and screws would also influence the price.
Societal Concerns- The original target age group of 1 ½ to 4 years old would have to be raised to at least 4 to 6 years old because of the increase in speed. We addressed this concern by adding the optional speed control cover, which would allow the parents to limit the speed the child could travel at.
Environmental Concerns- Increasing the size of the battery would increase the amount of waste that is produced for every car that is sold, and the increased size of the Jeep would also create that much more plastic waste.
Sources
[1]-Amazon?',, By. "Amazon.com: Fisher-Price Power Wheels Hot Wheels Jeep: Toys & Games." Web. 09 Dec. 2010. <http://www.amazon.com/Fisher-Price-Power-Wheels-Hot-Jeep/dp/B001MM1XOW/ref=sr_1_4?s=toys-and-games&ie=UTF8&qid=1291925184&sr=1-4>.
[2]-Numbers, By. "550 Size Motor." Hobbymasters Hobby Store: 7000 Square Feet of Hobbies. Web. 09 Dec. 2010. <http://www.hobbymasters.com/550sizemotor.aspx>.
[3]- Amazon?',, By. "Amazon.com: Power Wheels 12-Volt Rechargeable Battery: Toys & Games." Web. 09 Dec. 2010. <http://www.amazon.com/Power-Wheels-12-Volt-Rechargeable-Battery/dp/B00004TFT1/ref=pd_sim_dbs_t_2>.
