Product Dissection - Gate 2

From GICL Wiki
Revision as of 16:16, 20 December 2010 by MAE 277 2010 Group 16 (Talk | contribs)

(diff) ← Older revision | Latest revision (diff) | Newer revision → (diff)
Jump to: navigation, search

Contents

Purpose

Gate 2 contains the majority of the hands on physical work involved in this project. The group followed the plans established in Gate 1 to complete the tasks of this section. There are two major tasks, including the Preliminary Project Review and the Product Dissection.

The Preliminary Project Review will look back at the past several weeks of work and assess which parts of the initial plans were successful and which need adjustments, as well as providing a solution to any unresolved problems.

The Product Dissection section will effectively lay out the dissection step by step, answering questions about challenges, tools, and methods used. This would provide an individual who has never dealt with the product a clear plan for complete dissection.

Preliminary project review

Now that the Work and Management Plans have been put to use, it is time to support, critique, and adjust the plans. Overall, the plans have worked effectively in the sense that the team has moved through the dissection process seamlessly. There were only a few minor unforeseen issues in the dissection itself, which will be covered in the Product Archaeology portion of this gate.

Group 16 has been rolling along effectively, with a few minor changes to the Management Proposal. The parts of the plan that are working are working because the group discussed how we wanted the project to unfold before we started. Most notably, the subgroups that were proposed were replaced by an as needed approach. This new approach allows flexibility, so a group member can request as many partners as needed to accomplish the goals of the day. Since we received a relatively simple product in terms of dissection difficulty, the entire team decided to attend the two designated dissection days. This gives the entire group first-hand knowledge of the process. An example of the “as needed” approach is the Parts Technician returned to the lab for an extra night to assure we had each part properly represented, assisted by the Modeling Technician.

To this point, group meetings have not been necessary, with all information and plans discussed in class and by email. As we proceed into the next several gates, weekly meetings will be incorporated to ensure all aspects of the project continue to run smoothly. There have been no challenges thus far within the group. The only problem we have encountered thus far is in wiki development. No one in our group is familiar with wiki, so the familiarization process will take some time. To avoid this problem, everyone loaded their own work to the wiki for the first gate, giving everyone a basic knowledge of how the wiki works. To overcome the challenge, the wiki developer spent this time learning the wiki program in depth. Everyone taking care of their gate 1 wiki on their own provided this extra time for the wiki developer to learn the skills. In the future, challenges will be handled much in the same manner, with all members of the team aiding in the problem to account for a difficulty within the group. If the challenge involves a lacking team member, the process outlined in the project management section will be followed.

Parts List

The following table lists the parts that were taken from the Barbie KFX Kawasaki and its assembly units.

Part List
Part Number Part Quantity of Part Object Image Part Number Part Quantity Required Object Image
1 Body 1
Body G16.JPG
26 Forward/Reverse switch 1
Foward reverse control G16.JPG
2 Chassis 2
Chassis G16.JPG
27 Pedal 1
Foot pedal G16.JPG
3 Seat 1
Seat G16.JPG
28 Pushbutton Failsafe Switch (Accelerator switch) 1
Accelerator unit G16.JPG
4 Steering column 1
Steering column G16.JPG
29 Handel grips 2
Handle grips G16.JPG
5 Front clip 1
Front CLip G16.JPG
30 Steering column plate 1
Plate.JPG
6 Brush guard 1
Brush guard.JPG
31 Steering linkage cover 2
Steering linkage cover G16.JPG
7 Front wheels 2
Front Wheel G16.JPG
32 Wheel bushing 4
Wheel bushing G16.JPG
8 Rear wheels 2
Rear wheel G16.JPG
33 Steering Linkage lower bushing 2
Lower-bushing G16.JPG
9 Foot rest 2
Foot rest (rightside) G16.JPG
34 Steering column cap 1
Steering cap G16.JPG
10 Steering linkage 1
Linkage G16.jpg
35 Electrical wire harness 1
Harness assymbly G16.jpg
11 #7 19T Gearbox 2
- 7 Gear box complete G16.JPG
36 High speed switch cover 1
High speed control cover G16.JPG
12 19T pinion Motor 2
19T pinion gear motor G16.jpg
37 High speed wire harness 1
Turbo speed switch G16.JPG
13 Wheel cover 4
Wheel cover G16.JPG
38 Power relay PC board 1
Electronic brake G16.JPG
14 Spring cover 2
Spring cover G16.JPG
39 3/8" 16-hex nut 3
9 16 hex nut G16.JPG
15 Front axle 2
Front axle G16.JPG
40 7/16" Flat washer 7
7 16 flat washer G16.jpg
16 Rear axle 1
Rear axle G16.JPG
41 7/16” Tooth lock washer 2
Tooth lock washe G16r.jpg
17 Foot rest support rod 2
Foot rest support rods G16.JPG
42 8x2" Machine screw 4
-8x2 machine screw.JPG
18 Gear box cover 2
Gear box cove G16r.JPG
43 8x3/4" Machine screw 55
-8X3 4 machine screw G16.JPG
19 Driver 2
Driver G16.JPG
44 2" Fine thread machine screw 4
2 fine thread machine screw G16.JPG
20 Hub cap 4
Axle hub cap.JPG
45 3/4" Tap screw 8
3 4 tap screw G16.JPG
21 Forward/Reverse switch cover 1
Switch covering G16.JPG
46 2” Shoulder screw 1
Shoulder screw.jpg
22 79 Tooth gear 1
79 tooth gear G16.JPG
47 1/4” Machine screw 2
PC board screw.jpg
23 72 Tooth gear 1
72 tooth gear G16.JPG
48 12Volt Barbie Kawasaki charger 1
KFXcharger.JPG
24 62 Tooth gear 1
62 tooth gear G16.JPG
49 12 Volt battery 1
12volt battery.JPG
25 38 Tooth gear 1
38 tooth gear G16.JPG
50 Mock dash board 1
Handle bar mock dashboard G16.JPG
Table 1.

Assembly units

As stated before, the table below lists the assembly units contained in the Barbie KFX Kawasaki.

Assembly units list
Assembly number Name of Assembly Components of the Assembly Assembly Image
1 Gearbox motor Assembly 79 tooth gear, 72 tooth gear
62 tooth gear, 38 tooth gear
Gearbox casing
Gear box apart G16.JPG
2 Footboard Assembly Right side foot rest
Pedal
Failsafe switch accelerator switch
Foot rest support rods x2
Underside cover
Topside
Bottom side taken apart
3 Steering system assembly Steering linkage
Steering column
Steering column cap
Steering column plate
Front axles x2
steering linkage with cap, plate and axles
steering column
4 Wire Harness Assembly 19T pinion motor
PC Board connector
Failsafe switch connector
12volt Battery connector
High speed wire connector
Harness assymbly G16.jpg
Table 2.

Product Dissection Plan

The table below contains a detailed step-by-step procedure to aide in the dissection of the Barbie KFX Kawasaki. The dissection process by itself takes approximately 22 minutes with at least 2 people working at steps that had several parts that could be taken off simultaneously such as step 1. The entire process of the product dissection took approximately 3 hours over 2 days in which time was taken to document the dissection process with notes and images, documenting and organizing the parts in between the steps of taking apart the vehicle.

Special Recommendations:

Removal of rear axle:
The nut which holds the rear “passenger side” wheel on is secured with a significantly greater force than the opposite nut. Therefore one should not attempt to remove this nut themselves. One should instead remove only the “drivers side” wheel, nut, and driver, and then slide the whole axle out of the rear of the vehicle which will pull the wheel and driver assembly with it.

Removal of the tooth lock washer:
The tooth lock washers which hold the front axles to the steering linkage require a lot of force to remove. These clips can be removed with a flat head screwdriver. Exercise caution when utilizing the screwdriver to pry these clips off, as the excessive force on the screwdriver may cause the head to slip off the clip and cause serious injury.

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
- 1/8" Craftsman Flat head screwdriver
- P1 and P2 Phillips head screwdrivers

Difficulty Scale
1- Easy: Basic knowledge of household hardware tools(i.e screwdrivers, wrenches and so forth) required and removal of the part is a simple action i.e removing pulling out a rod from a hole.
2- Medium: Needed some prior thinking to remove the part as to not break it.
3- Hard: Multiple attempts were made to remove the part due the part not intended to be removed easily with conventional home tools.

Explanation of the scale:
Parts that were held either by screws or simply held in place by other parts being attached to it(i.e rear axle, and footrest support rods) are easy to remove with basic knowledge of household hardware tools and the axles can simply be pulled out from where they are held after the parts holding them were removed. For parts that needed prior thinking, the part had to be looked at and observed carefully as to devise an efficient way to remove it without damaging it or causing harm to the person removing it. Reasons for this included the part not originally intended to be removed but still can be removed with conventional home tools(i.e screwdriver). The only procedure that registered a 3 on the scale was the removal of the toothlock washers because they are intended not to be taken off easily due to the teeth on the washer being angled upward. They were likely put on by a pressure machine that took a fraction of second to perform the task. As a result a flat head screwdriver was used to pry it off on all sides as to not break the washer.

Product dissection procedure
Step Procedure Tool required Approximate time required Difficulty scale(1-3) Image of the process
1 Take off the hub caps from the wheels by using a flathead screwdriver by wedging the screw driver between the hub cap clip and the wheel cover where there are slits where the hub cap fits into in the wheel cover. The image shows where the flat head should be placed to pry out the hub caps. 1/8" Flathead screwdriver 1:00 1
Arrows pointing to where the hub cap clips fits and should be pried out
2 Remove the wheel covers(4) by first removing the 3/8" 16-hex nut(3) from the two front wheels and from 1 of the rear wheels. Then simply remove the wheel covers from the front wheels and from the rear wheel where the hex nut was removed. 9/16" socket wrench with a 3/8" drive 3" long Socket extension. 2:00 2
Rear end wheel with hub and wheel caps removed
3 Remove the wheels(2), washers and bushings from the front axle and the rear end wheel where the hex nut and wheel cover was removed. Then remove the driver and the wheel bushing from the side where the rear end wheel was removed. Remove the rear end axle by carefully pulling it out from the side where the rear end wheel has not been removed and then remove the wheel cover, driver and bushing from the axle. none 00:30 2
Front axle parts removal
Rear axle parts removal
Rear axle removal
4 Remove the brush guard by removing the 4 #8x3/4" machine screws with a P1 Philips head screwdriver. Then remove the 2 #8x3/4" machine screws from the front clip to remove it from the chassis. P1 Philips head screwdriver 00:30 1
Left image showing brush being removed and the right shows the front clip being removed
5 Remove the steering linkage cap by using a P1 Philips head to remove the #8x3/4" machine screws(2 per cap). Now remove the steering column cap by removing the #8x3/4" machine screw with a P1 Philips head screwdriver. P1 Philips head screwdriver 1:00 1
Steering linkage cap removed
6 Remove the column plate by first removing its #8x3/4 machine screw with a P1 Philips head screwdriver, then with a 1/8" Flat head screwdriver carefully force it out from the bottom of the chassis. Then remove the steering column from the chassis while carefully fishing out the high speed wire that is connected to the steering column through the hole where the steering column is located. 1/8" Flathead screwdriver
P1 Philips head screwdriver
1:00 2
steering plate and steering column cap shown
7 Remove the handle grips from the steering column handle bars and remove the high speed wire cover using a P1 Philips head to remove 3 #8x3/4" machine screws. Remove 2 #8x3/4" machine screws from the mock dashboard cover to remove it. P1 Philips head screwdriver 1:00 2
steering column taken apart
8 First remove the seat by pressing the clip at the back end to remove it from the body. Afterwards check if the high speed wire connector is connected to the electrical wire assembly. If it is, remove the connector from the wire assembly. Remove the body by using a P1 Philips head screwdriver to remove the #8x3/4" machine screws(8) attaching the body to the chassis. P1 Philips head screwdriver 2:00 1
chassis with body and seat removed
9 Remove the tooth lock washers(2) that are attaching the steering linkage to the chassis by prying it off with a 1/8" flat head screwdriver. Do this by wedging the flat head under the washer as shown in the image by red arrows. To impede the destruction of the washer, the washer should be pried off at all sides. The steering linkage and the front axles will fallout from under so it is suggest another person hold them for support and to prevent damage. 1/8” Flathead screwdriver 1:30 3
Arrows showing where to wedge the flat head
10 Remove the front axles(2) the steering linkage, none 00:30 1
steering linkage with out the axles
11 First remove the he 2 #8x3/4" machine screws with a P1 Philips head screwdriver holding the forward/reverse switch cover to the body. Once the screws are out, the cover can be lifted off the body exposing the forward/reverse switch connection. Detach the forward/reverse switch from the electric wire assembly which will allow removal of the switch and cover. P1 Philips head screwdriver 1:00 2
cover detached from body with connection exposed
12 Use a P1 Philips head screwdriver to remove the #8x3/4" machine screws(2) from the left foot rest. Then carefully pull out the left foot rest and the foot rest support rods(2) and it is suggested that another person hold the right foot rest for some support. P1 Philips head screwdriver 2:00 1
Foot rest and support rods removed
13 Use the P1 Philips head screwdriver to remove the 2 #8x3/4" machine screws from the right foot rest. Then remove the #8x3/4" machine screws from the Failsafe accelerator switch cover from the underside of the right side foot rest. Now detach the Failsafe accelerator switch from the electric wire assembly connector. Then remove the 2" shoulder screw with a P1 Philips head screwdriver to remove the pedal from the cover. The right side foot rest can now be completely removed from the chassis. P1 Philips head screwdriver 3:00 1
Right foot rest with accelerator switch detached from the wire assembly
14 Remove 3 #8x3/4" machine screws from each gearbox cover(2) from both sides of the chassis using a P1 Philips head screwdriver P1 Philips head screwdriver 00:30 1
gearbox cover removed
15 Detach the gearbox(2) from the 19T Pinion motor by removing the 2" fine thread machine screws(2 per gearbox) with a 1/8" flat head screwdriver. 1/8" Flathead screwdriver 00:30 1
Motor with gearbox removed
16 First remove the plastic spring covers with a 1/8" Flathead screw driver by wedging the screwdriver between the spring cover clips and carefully prying them off. Take apart the chassis by using a P1 Philips head screwdriver to remove the #8x3/4" machine screws(14) holding the chassis together. P1 Philips head screwdriver 3:00 2
chassis pulled apart
17 Remove the PC Board from the chassis by first detaching the wire assembly PC board connectors and then using a P1 Philips head screwdriver to remove the 3/8" machine screws(2) from the PC board. The wire assembly can now be removed easily from the chassis as well. P1 Philips head screwdriver 00:30 1
chassis with PC board and wire assembly
18 Take apart the gearboxes(2) by removing the 3 #8x3/4" tap screws(3) with a P1 Philips head screwdriver. The gears will then simply slide out of the gearbox. P1 Philips head screwdriver 00:45 1
Gearbox taken apart with gears
Table 3.

Intention of Disassembly

The KFX Barbie Kawasaki is a child's toy and is not meant to be disassembled regularly. This is because the overall complexity is relatively low compared to an actual ATV. Due to this low complexity, the only maintenance that would need to be performed would be cleaning the product and the occasional inspection of the product before use to make sure it is functioning correctly. So breaking down the product is not needed at all.

There are however, many parts that are connected by screws or hex nuts; objects that can be removed by the common Philips head screwdriver and socket wrench. It can be stated that these parts are allowed to be disassembled, not necessarily meant to be disassembled in the event that a part would need to be taken apart to correct functionality such as if some weeds became wrapped up in the axles. Then the wheels would need to be removed from the axle and to do so one would need a socket wrench, a common tool in the average household.

The one part that is meant to be taken apart from the product regularly and for functionality purposes are the seat and the high speed wire connector. The seat covers the section of the chassis where the 12v battery goes and the compartment housing the high speed wire connection. This conclusion was made based on that the battery would need to be recharged and removed from the product. Removal of the seat allows access to the high speed wire connection to allow parents to enable the high speed option. The seat is connected to the product by a snap clip, a common fastener that allows for easy removal. Theoretically, this would allow easy access to the battery and the high speed connector for the user(child) as well. So potentially the child could figure out how to enable high speed for themselves or interact with the battery. Although this presents possible safety issue, the model of batteries that the Barbie KFX Kawsaki uses are generally heavy and the child would likely not have the strength to remove it. Also it is unlikely that the child would figure out how the high speed connection works at the age of 3. At older ages, the child would likely be able to handle the high speed and by then have the option already enabled by the parents.

It was concluded that the following parts were not intended to be disassembled

Steering Linkage and Tooth Lock washers
The steering linkage is secured to the chassis by two tooth lock washers. The washers have teeth angled upward so that they dig into the axle and prevent the washers from being popped off. This indicates that the steering linkage and the washers are not meant to be removed from the chassis.

Steering Column
Because the steering column is connected to the steering linkage and can not be removed unless the steering linkage is removed as well, this also implies the steering column is not intended to be disassembled as well.

Gearbox and Motor
Although the gearbox can be disassembled easily, it is not meant to be taken apart because of the chemical materials inside of it that pose a potential danger to the user. Taking apart the gearbox and reassembling it incorrectly will cause a cease of function, however because of the shapes of the gears, it would eventually be placed back together properly by trial and error. If maintenance needs to be done on the gearbox, it would have to be taken to a service center. The motor/gearbox assembly is also not meant to be taken apart due the complexity of assembling both the parts and ensuring that they function properly. The assembly is located in the chassis and to even reach these parts requires removing the entire rear axle along with the wheels. The motor is a very complex part in terms of function and assembly. If the motor were to be disassembled, there is a high chance that the motor would end up being destroyed in the process (without extensive technical knowledge) rendering it useless.

Product Dissection Assessment

Difficulty of dissection
In general, each component on this product was easily removed. In Table 3 above, the difficulty of each individual part's removal is assessed. The exceptions to this smooth dis-assembly procedure included the removal of the tooth lock washer and the "passenger side" rear lug nut. The tooth lock washer holds the front axles in place, and requires considerable force to remove, therefore it can be concluded that the front axle is not intended to be taken apart. Of the two rear lug nuts, only one was originally installed to be literally permanent on the rear axle. This nut was put on with such force, that no combination of wrenches, and or vice grips could remove it. Although it is still possible, then to remove the rear axle from the motor/gear box assembly, the nut was never removed, which helps to draw the conclusion that the wheels were probably not supposed to be removed by the consumer.

Subsystems
In the Barbie Kawasaki KFX, there are several subsystems that work together that enable the product to achieve its primary function. These subsystems include the steering column, the wheels, speed control and the motor. Figure 1. shows how the steering column connects to the chassis. The bottom of the steering column is connected to the front axle wheels by the steering linkage and is further secured against the chassis by a plastic clip(shown in figure. 2) The bottom of the steering column fits into a hole in the steering linkage which transfers the rotational energy from the handlebars, inputted by the user to the axle. This allows for the directional signal from the column to be translated to the wheels. Human energy is transferred from the operator, to the steering column in the form of rotational energy, to the wheels by means of the steering linkage. The other connected subsystems are the motor, speed control and the rear axle wheels, the last two are connected via the gearbox. The foot pedal is connected to the speed control via wires that output to the motor the desired speed. The motors are connected to the speed control and battery by more wires. There are two motors, one on each rear wheel. The gearbox is physically connected to the motor at one end(see figure 3.), and at another end the rear axle is fed through the hole in the gearbox(see figure.4). The axle goes into the gearbox and has a gear that allows for the rotation, while the gearbox itself is connected to the frame by the axle and a cover the keeps the gearbox secure against the frame. The signal is an input from the pedal, to the speed control to the motor, which in turn signals the battery to translate electricity into Kinetic energy, moving the gears and turning the axle.

Connections
The connections of each subsystem are implemented in a few different manners ranging from steering linkage connecting the steering column to the front axle, to the gearbox that connects the motor and the rear axle. Influencing these connections are some different factors. This product is aimed to be sold in America, and with the money in this country, companies are allowed to use technology on recreational vehicles, even toy such as the Barbie KFX Kawsaki. But since making money is also a factor, Fisher Price can use a plastic clip to connect two of the most important parts of the product, instead of using a metal clip. Society plays a role here as well. Since it is acceptable, and pretty much the norm, to use plastic over metal for many things in our world, consumers would not think twice as long as there was no doubt about the safety of the product. Environmental concerns led to the creation of a mostly plastic model, and choosing a standard 12 V battery that isn’t necessarily environmentally friendly, but is cheap and acceptable. Fisher price and the Power Wheels brand are trusted brands and this also implies a level of trust between the company and consumers.
The performance of this product is relatively low, so the connections don’t need to be as strong and secure as a sports car per say, but still need to account for child safety. The area of highest importance for performance is the motor and gearbox, and the gears are all plastic, encased in a plastic box. This allows for the reduction of money spent and the decreasing the weight of the prodcut.

Arrangement
The subsystems are arranged in manner that replicates a standard vehicle. The steering column being in the front right by the seat and the wheels are underneath the body. The motor is located in the body close to the rear axle so that the lost energy from transportation is minimized. And finally, the speed control is located by the foot pedal and in the throttle which is located in the steering column. The foot pedal is placed where your feet hang for comfort and ease of access and the throttle is in the handle for ease of use and access. The steering column and steering linkage subsystems must be adjacent to eachother in order to carry out the function of steering the product. The motor gearbox assembly and rear axle system must be adjacent to eachother to effectively perform the action of creating translational motion. However the steering system(steering column, steering linkage) can not be adjacent to the motor system(gearbox, motor, rear axle) as doing would impede the functionality of the product.

Main Page

Main Page

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]"Gear box Identification." Mltoyz.com 19 OCT 2010 <http://www.mltoyz.com/gb/index.html> [4]"Washers." Mcmaster.com 20 OCT 2010 <http://www.mcmaster.com/#washers/=9dxu8z>
[5]"Screws." Mcmaster.com 20 OCT 2010 <http://www.mcmaster.com/#screws/=9dxvso>
[6]"Digi-Key - PB380-ND (Manufacturer - T7NS5D1-12)." Digikey.com 20 OCT 2010 <http://search.digikey.com/scripts/DkSearch/dksus.dll?WT.z_header=search_go&lang=en&site=us&keywords=T7NS5D1-12&x=22&y=22>
[7]"Pushbutton Failsafe switch." Hellotrade.com 21 OCT 2010 <http://www.hellotrade.com/lamb-industries/pushbutton-failsafe-switch.html>