Product Explanation - Gate 4

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Contents

Purpose

This portion of the project consists largely of the reassembly of the product. Using the information gathered in this process and throughout the project so far, detailed conclusions will be made about the Barbie Kawasaki KFX.

Critical Project Review

As we have come to the end of the year, everyone finds themselves stretching further than they go to accomplish what they need to do. Naturally, this puts stress on the group as many of the most important parts of the project approach. Our time management issued was very successfully solved throughout this gate in particular. We solved the problem using two major strategies. First, by making sure only the people needed went to group meetings, we saved the time of the others people. This saved time could then be put towards other parts of the project with no added strain on the group member. For example, since the presentation overlapped with this gate, it became a time stressor. To reduce that time stress, the group members who were presenting did not attend the meeting in which the presentation was developed. That saved time was put towards presentation adjustments and practicing for the presentation. Secondly, as schedules got tighter throughout the group, times that used to work for everyone were now slimmed down. To combat this issue, group members were more understand when others had commitments, and everyone made it to appropriate meetings when they could. For example, on the night of our product reassembly, two of the group members had the early part of night available and showed up first to set up. Another two had from the middle of the night on available, so they showed up and worked through the rest of the night. The last group member had the end of the night available, so he took over when two of the earlier workers had to leave. The keys to solving this issue were understanding attitudes and good time management skills. At this point in time we have only one minor unresolved challenge to face, and that is the corrections of past errors. To solve this we will assign everyone certain parts to edit, requiring that we successfully distribute the grading sheets by scanning and distributing. People will be assigned the part they originally worked on because they know that portion of the project the best. The remainder of this project should continue to run smoothly.

Product Archaeology

This Section details the reassembly process of the Barbie KFX Kawasaki.

Original Assembly

The Barbie KFX Kawasaki is manufactured in Mexico so a possible assembly line process could be where, at the first station, the gearbox motor assembly and wire assembly would be attached to the chassis. These assemblies would be fastened by screws with a philips head screwdriver. The product would be moved to the next station where the chassis is put together then the foot rest assemblies are done, all fastened together with the use of srews with a philips head screwdriver. The next station would either assemble the front clip and brush guard, body, or the rear axle assembly with the rear wheels fassened with two 9/16" socket wrenches one on each side of the rear axle. The product would move on to another station and have the steering linkage, steering column, and the forward/backwards switch assembled with the use of screws and a philips head screwdriver. Then finish off with the front wheels fassened using a 9/16" socket wrench and finally the seat which clips into the chassis. This process could also be performed entirely at one station where a set of workers assembles the entire product in one sitting, assembling several products in one day. There is also the possibility that the assembly process is entirely automated which would cut down on the use of many workers on the assemly line and also increase the speed of production.

Product Reassembly

The Barbie KFX Kawasaki was put back together in approximately 2 hours and 20 minutes which included the process itself and discussion of how to carry out each step. Table 1 describes the assembly process step by step while table 2 and 3 describe the assembly of the right footrest/foot board and steering column subsystems.

\'\'\'Note:\'\'\' Images shown with annotations should be viewed in full size to view the annotations properly.

The assembly process of the Barbie KFX Kawasaki has some variations from the disassembly process other than simply the reverse of some of the steps. The significant variations were that with the toothlock washers, they needed to be hammered down while in the dissassembly they were pryed off and for the assembly of the rear wheels and axle, several parts need to be put in the axle prior to putting it through the back of the chassis.


\'\'\'Tools Required\'\'\'

- 9/16" Socket Wrench or the 9/16" wrench assembly tool that comes with the Barbie Kawasaki KFX
- 3/8" drive 3" long Socket extension
- 9/16" socket 4" extension
- 1/8" Craftsman Flat head screwdriver
- P1 Phillips head screwdriver
- Hammer

\'\'\'Difficulty scale\'\'\'
\'\'\'1 (easy)\'\'\'- Assembly of the part requires basic knowledge of common hardware tools (i.e Philips head screwdriver, hammer and socket wrench) or the part is assembled with no tools and only requires an action as simple as placing a rod through a hole.
\'\'\'2 (medium)\'\'\'- Assembly of the part needed to be forced on in order to fit. No special tools necessary but can still be used to quicken the process.
\'\'\'3 (hard)\'\'\'- A method of assembly needs to be improvised due to a lack of proper tools that originally assembled the part at the time of reassembly.(This ranking may or may not apply based on technical background. See explanation below)

\'\'\'Explanation of the scale:\'\'\'
Steps such as step 13 of the assembly process are scaled 1 because the action of assembling requires no technical background, only basic knowledge of household hand tools like screwdrivers. For example, placing the front axle caps on the front axles is just a simple action of placing the cap over the front axle as described in the associated image and in the procedure. Securing the cap requires using a Philips head screwdriver to fasten the machine screws which requires only basic knowledge of hand tools.

Only 2 steps ranked a 2 on the scale which were steps 3 and 4 of the assembly of the steering column. Assembling the handle bar grips is a simple process of just sliding them on the handle bars. However the handlebar grips are designed to fit very tightly on the bar so that they do not slip during usage so they will have be forced on. No tools are necessary for forcing on the handle bar grips, just heavy pressure.

Only step 10 of the assembly process ranked a 3 on the scale. The reason for this ranking is because the tooth lock washers attaching the front axles to the steering linkage were likely assembled by some sort of press machine that presses the tooth lock washer onto the front axles. Such a tool was not available during the time of assembly so the group had to devise a method of attaching the washers. The group ended up using a socket from a socket wrench to place over the washer and hammer the washer down as far as possible along the front axle. The difficulty of this step may vary depending on the technical background of the person or people assembling the Barbie KFX Kawasaki. For instance a mechanic may quickly come up with a method due to their profession or may actually have a tool that can perform the operation as opposed to an average person (with little engineering knowledge) who may have a harder time devising a solution.

\'\'\'Challenges of assembly:\'\'\'
Our only two challenges were the assembly of the motor to the gearbox and reassembling the toothlock washers, The toothlock washer was most likely attached to the front axle by a machine that obviously the group did not have access to. So we had to come up with a way to push the washer back on the axle without breaking it and making sure that we had a secure connection. We ended up using a 9/16" socket to put over the washer and used a hammer to force it down for a tight fit.

\'\'\'Note:\'\'\' It is recommended that the assembly is done in pairs of people to make the process faster and easier.

-*see Table 2 for the assembly of this part.
-**see Table 3 for the assembly of this part.

Product reassembly procedure
Step Procedure Tool required Approximate time required Difficulty scale(1-3) Image of the process
1 Attach the PC board to the right side chassis frame as shown in the image in the rear end. There will be a letter R marking on the inside identifying the right side frame. Use a Philips head screwdriver and put in two screws to secure the board as shown in the image.Then attach the shown connectors to the PC Board making sure to align the connectors correctly. On the PC Board there will be letters that label the orientation of the color of the wires in the connectors. P1 Philips Head screwdriver 00:45 1
Location of PC Board
Pc Board connectors
2 First feed the Accelerator switch connector through the hole in the right side chassis frame as shown. Then put the two chassis frames together and screw in 18 #8x3/4" machine screws with a P1 Philips head. P1 Philips Head screwdriver 1:50 1
Connector fed through right side
Accelerator connector
3 First put the two foot pad support rods through the two circular holes in the chassis located in the middle of the sides and at the bottom. Attach the right foot pad assembly* to the right side of the chassis as shown and fasten it to the chassis with 2 #8x3/4" machine screws with a P1 Philips head. Do the same for the left side foot rest. P1 Philips Head screwdriver 2:30 1
Top side of right footrest
Top side of left footrest

Underside of right footrest
Underside of left footrest
4 Attach the body frame to the chassis making sure it is secure. Then fasten it with 8 #8x3/4" machine screws with a P1 Philips head. P1 Philips Head screwdriver 1:00 1
Body attached to chassis
5 Attach the gearbox to the motors using a 1/8" flat head screwdriver to fasten 2 2" fine thread machine screws(2 per gearbox motor assembly). The screw holes on the side of the motor with the pinion should line up with the holes indicated in the image with a red line.(There were no markings to indicate which motor should be on the left or right, so it was assumed that the motors are to be arranged so that the wires are not crossing each other.) To determine which gearbox should be on the left/right, when preparing to attach the motor to the gearbox, the holes where the screws go in to attach the motor should be on the bottom with the white gear point away from the chassis. The image shows a clarification of this. 1/8" Flat Head Screwdriver 4:30 1
Blue arrow indicates where the Motor pinion goes.
6 Put the gearbox in the chassis as shown in the image and by the red arrow, the end with the motor attached should fit inside the chassis.(Not the whole gearbox goes into the chassis) Then use a P1 Philips head to fasten the gearbox cover to the chassis with 3 #8x3/4" machine screws. This step is done twice as there are two gearbox covers and two gearboxes. It does not matter which gearbox cover goes on the left/right as they are identical. P1 Philips Head screwdriver 2:00 1
Red arrow indicates where to put the gearbox
Gearbox in the chassis
7 Put the steering column assembly** through the hole in the front of the Barbie KFX Kawasaki while feeding the turbo cable through the same hole and into the compartment as shown. Make sure the front of the dash board faces forward. The front of the dash board is the ramped side. The red arrows indicates the hole where the steering column is to be placed and the blue arrow shows the compartment where the turbo wire will end up. None 1:00 1
arrows showing location of steering column and turbo wire
Steering column attached
8 Attach the column plate to the bottom of the chassis as shown and fasten it with a #8x3/4" machine screw with a P1 Philips head. P1 Philips Head screwdriver 00:20 1
DSC04411.JPG
9 Attach the front axles to the sides of the steering linkage( the front axles are identical so it will not matter which side the axles goes on). Then attach the steering linkage to the bottom of the chassis as shown. Then attach the steering column cap to the tip of the steering column bar and fasten it with a #8x3/4" machine screw with a P1 Philips head. P1 Philips Head screwdriver 1:00 1
Red circle is where the cap goes
Cap attached
10 First support the vehicle properly and place it on a flat surface. Take the 7/16" toothlock washer and place it on top of the front axle as shown with the teeth pointing upward. Take a 9/16" socket 4" extension(a longer one works as well, a 4" one was used because there is no difference in using a longer one as opposed to a 4" extension which is the minimum needed) and place it on the toothlock washer with the hex nut end facing downward. Take a hammer and hit the socket from the top which will force the toothlock washer down. Do so until the toothlock washer is tightly holding the front axle against the chassis. This step is performed twice, once for each front axle. Hammer
9/16" Socket 4" extension
3:00 3(may vary see difficulty scale explanation)
Placement of washer
washer fully fastened to axle
11 Take the rear axle and put the following components in the mentioned order on the rear axle, wheel cover, rear wheel, wheel bushing, driver as shown in the image. When putting the wheel on the axle, the wheel cover should fit into the dipped inner radius. When assembling the driver, the shaft needs to fit into the white visible gear of the gear box so that the teeth of the gear fits with the lines of the driver on the inside of its shaft. The wheel on one side has four ridges that need to fit with the notches of the end of the driver. None 1:30 1
Note:Driver not shown in this image
Driver locking with the wheel
12 Feed the rear axle through the gearbox(there is a hole in the center of the white visible gear)and the hole in the rear of the chassis which should be lined up with the hole in the gearbox.(The side does not matter) Then place the parts on the other side the axle when it has been fed through in the following order, driver, 1/8th flat washer, wheel bushing, rear wheel, wheel cover. Once this is done, attach the 9/16" hex nut to the end of the axle and tighten snuggly using 2 9/16" wrenches (one on each side of the axle). 9/16" Sockets Wrench 1:30 1
Red arrow showing where the axle is fed
Rear axle and wheels assembled
13 Put the front axle caps(2) on the front axles and secure them with 2 #8x3/4" machine screws for each axle cap with a P1 Philips head. P1 Philips Head screwdriver 00:30 1
DSC04416.JPG
14 Place the 7/16" washer, wheel bushing(shaft end pointing outward), front wheel(the mostly flat side goes against the vehicle) and the wheel cover(should fit inside the wheel) in the stated order. Then fasten the end of the axle with a 9/16" hex nut. This step is done twice, once for each front axle. 9/16" Socket Wrench 00:30 1
arranged of the bushing and washer
wheel cover attached
15 Attach the 4 hub caps to the wheels, one for each over where the end of the axle showing in the wheel where the hex nuts are placed. The connection of the hub cap is a simple snap connection. The image shows where the snap clips go into. None 00:20 1
Red arrow showing where the snap clips go
16 Insert the top of the front clip in between the front of body and the chassis as shown in the image. Then secure the brush guard in front of the front clip as shown and fasten it to the chassis with 4 8x3/4" machine screw with a P1 Philips head. P1 Philips head screwdriver 00:40 1
Red arrows showing the space where the top of the front clip goes
Arrows showing the top pointing to the top of the clip
Front clip and Brush guard assembled
17 Place the forward/reverse switch into the rectangular hole in the cover and connect it to the forward/reverse connector. Place the forward/reverse cover at the front of the Barbie KFX Kawasaki in the shown location which should be in the front and on top of the vehicle and behind the steering column and secure it with 2 #8x3/4" machine screws with a P1 Philips head. The switch should snap in place. Then put the seat on the body covering the large gap in the middle of the vehicle. The seat has snap clip in the back that should snap it into place and should be towards the rear of the vehicle. P1 Philips Head screwdriver 00:30 1
Locations of parts shown
Forward/reverse switch connected
Cover attached
Table 1.

Assembly Units

Note: Assembly for the footpad

Footpad Assembly reconstruction
Step Procedure Tool required Approximate time required Difficulty scale(1-3) Image of the process
1 Attach the accelerator to the right side footpad rest(the one with the square opening in the middle of it. The accelerator has a little edge that needs to fit with the slot in the footpad rest as shown in the image. The accelerator should fit in the pedal with its clips and go into to the hole from the top prongs first. None 00:35 1
Foot petal assembly (accelerator).JPG
2 Take the pedal and attach it to the topside of the footrest where there will be a small rectangular slot for the end of the pedal with a clip to fit into(shown by the red arrow). Then take the 2" fine thread machine screw and put it through the slot in the front of the pad from the bottom of the footrest thread end first.(Shown by the blue arrow) Then fasten the pedal to the machine screw with a P1 Philips head. P1 Philips Head Screwdriver 00:35 1
arrows showing the slots where the clip and machine screw go
Pedal and machine screw assembled to the foot rest
3 Attach the accelerator connector to the accelerator. Orient the wire as shown in the image to allow the cover to go on properly. Then place the cover on the footrest as shown and use a P1 Philips head to screw in 4 #8x3/4" machine screws. None 00:15 1
Setup of the accelerator wire
right footrest assemled
Table 2.
Steering column assembly
Step Procedure Tool required Approximate time required Difficulty scale(1-3) Image of the process
1 Take the mock dash board and attach it to the plastic under casing on the steering column as shown in the image. Fasten the two pieces together with 4 8x2" machine screws with a P1 Philips head. The holes for the screws will be on the underside of the bottom dash board casing. P1 Philips head screwdriver 1:00 1
Annotated.JPG
2 Slide the left side turbo switch casing(the one without the handlebar grip) on the right handle bar which is the bar with the smaller radius. Make sure that the rectangular ridge is facing up as shown in the image. Then take the handle bar grip with the other side of the casing and slide it onto the same handlebar but not all the way, leave some space between it and the other casing. none 00:40 1
DSC04399.JPG
Red arrow showing area that should be facing upward
3 Place the turbo switch in the casing as shown in the image. Then adjust the wire so it fits tightly in the casing. Now put the two casings together preferable keeping the casing without the grip as far along the bar as possible while bring the other casing with the grip to it. Secure the case with 3 8x3/4" machine screws with a P1 Philips head. Push the handlebar grip and casing as far along the steering column bar as possible to secure it. P1 Philips head screwdriver 2:00 2
arrange of turbo switch
4 Now slide the left handlebar grip on the left bar of the steering column and push it against the bar as much as possible to get a tight secure fit. none 00:30 2
Steering assembly complete
Table 3.

Design Revisions

The follow statements outline 3 system design revisions that we came to a conclusion on and that we thought would best improve the product at a system level. This does not mean that the product built by Fisher-Price is substandard in anyway.
Converting to four wheel drive:
The first design revision to be discussed is a conversion from two wheel drive to four wheel drive making the KFX more enjoyable to the user as it would be able to drive through various terrains. This is a very complex design change, since it will affect a majority of the components on the vehicle.
The first thing that must be changed is the placement of the motors. In its original state, the KFX has two motors in the rear each attached to a gearbox. To make the conversion to 4WD, there must be motors in the back and front. Otherwise some sort of torque converter would have to be used to get the power from the rear to the front (i.e. a belt or driveshaft). For our purposes we will assume that there are going to be motors and gearboxes in the front and rear of the vehicle. This means that the shape of the front end must be made slightly larger to accommodate the space required for the addition of these parts.
The second change that must be made is the addition of a solid axle in the front of the KFX. Since the original design was comprised of two independent axles to allow for steering in the front end, the addition of a solid axle will as a result affect the original steering design.
With the addition of the solid axle, the third change to be made is a new steering system. A rack and pinion steering system similar to what cars use will be considered to accommodate this design revision(See figure 1. below). This means that the axle will have to have a form of rack attached to the top surface of it, and the steering column will simply need a pinion which when turned, will cause the rack to move left to right, thereby turning the vehicle. I
The fourth and final change that must be made for this design revision is the altering of the electrical system. Assuming the same battery will be used; (albeit, the battery will drain faster) the speed control will have to be replaced with one capable of controlling all four motors. Also, there will have to be wires running to the front end from the speed control to power the two additional motors.


Figure. 1 Steering rack pinion in a car

Increase in motor power:
The next design revision focuses on a change in motor power. (This design revision could be combined with the above design revision to help provide a longer running time per charge) An increase in motor power could allow for a faster driving experience, although our aim isn’t to change the marketed age group of 3 years+, rather it is to help the vehicle drive through its expected environment such as tall grass, bumps, and gravel. If more powerful motors were used, without changing anything else, the battery would drain at a much faster rate. The solution to this problem will be the addition of a new, more powerful 12 volt Li-ion battery. The biggest change that will come as a result of this design revision is the increase in cost. Since the motors now have an increased power and longer run time, a change in the gear ratio will be made to make use of the increased torque output of the new motors. To maintain a similar top speed of 5mph, the gear ratio will have to be reduced relative to the change in motor power. Since the gear ratio has now been altered, it is likely that we will have to change either the shape of the gear box and or the placement of the gears in the gearbox. Therefore it should be noted that depending on the change in motor power, the gearbox will likely have to be redesigned.

Addition of Suspension:
The last design revision to be discussed is the addition of suspension to the Kawasaki KFX. The addition of suspension to this vehicle will make it look and ride more like an actual ATV, which is what the product is of course modeled after. The first and most critical change which the addition of suspension will cause is a new chassis design. The chassis must be isolated from the axles and power plant(s) by the implementation of small shocks, and springs. The part of the chassis which currently contains the gearboxes and motors must now be designed to move independently from the main chassis and body of the vehicle which the user rides on. The front axle and steering system will also be separated from the main chassis. The next change that must be made with the addition of suspension is the addition of suspension arms which will connect the axles and motor/gearbox assemblies to the actual shocks. The shocks will be attached to the underside of the rear and front of the chassis, as well as the top of each of the four suspension arms. The last change to be made to the KFX regarding this design revision is the addition of a universal joint to the steering column. Installing this joint in the steering column will allow the front axle to move freely up and down without the restriction of a stiff steering column, while still allowing the user to steer the vehicle in a safe manner.


The Factors affected by these Revisions

Each of these design revisions address one factor in particular, Societal. The four-wheel drive and suspension revision are meant to increase the performance of the vehicle on all surfaces. The addition of 4 wheel drive will give the Barbie KFX an edge over the competitor and as long as the price doesn’t rise too much, will give it a significant advantage in the marketplace. As well as the battery revision, these revision are meant to increase the performance of the vehicle, while keeping the prices low to keep this product competitive in the American market.

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References

[1]"Barbie™ Kawasaki® KFX with Monster Traction™." Fisher-price.com 27 SEPT 2010 <http://www.fisher-price.com/us/powerwheels/product.aspx?pid=47340>
[2]"Power Wheels Parts Diagrams." mendingshed.com 13 OCT 2010 <http://powerwheels.mendingshed.com/P5066.pdf>
[3]"How car steering works." Howstuffworks.com 9 DEC 2010 <http://static.howstuffworks.com/gif/steering-rack.jpg>