Remote control tarantula
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==Executive summary== | ==Executive summary== | ||
==Customer needs== | ==Customer needs== | ||
+ | The Tarantula is designed primarily as a form of entertainment for its user, and to a lesser degree, as an educational tool. | ||
+ | |||
+ | |||
+ | Users of this product seek out the novelty of a seemingly ‘alive’, self-contained creature, that they in turn are able to manipulate and direct, remotely. They may use it to observe the walking behavior of a simulated tarantula; more likely, they may use it to scare other people. | ||
+ | |||
+ | |||
+ | To this end, the user would require that the tarantula be '''durable, realistic,''' and '''easy to operate.''' | ||
+ | |||
+ | ===Durability=== | ||
+ | Ideally, the tarantula would be able to durable enough to function in different environments: indoors, outdoors, and on a variety of surfaces, including carpets and tile. The tarantula may be placed in an elevated location and then drop; therefore, the tarantula should be able to survive falls. The tarantula would also be frequently exposed to a younger audience, so it would need to survive pulling, tugging, tosses, and possibly even being struck or chewed on. | ||
+ | |||
+ | ===Realism=== | ||
+ | In order to convince other people that the tarantula is alive – even momentarily – the user requires a certain degree of realism. The user would want the tarantula to appear physically realistic, therefore it should be of the same size, color and texture as a generic ‘tarantula,’ or specifically, what the general population believes a tarantula to resemble. The user would also want the tarantula to have a realistic motion – its individual legs should move in a similar fashion to a real arachnid. The user would want the arachnid to not make a lot of noise – mechanical whirring would be a clear giveaway. Because a typical human being can easily cross a room in several seconds, the tarantula should be somewhat fast in its mobility. The goal would not be to outrun a person, necessarily, but to be able to encroach a person very quickly. | ||
+ | |||
+ | ===Ease of Use=== | ||
+ | Finally, the tarantula should be easy to operate. The user expects it to operate in a similar fashion to motor vehicles or other RC cars – in that navigating should be easy. The remote control’s buttons should be few and clearly labeled. The user would not expect to be required to articulate each individual leg, for example. Supervising adults would require that the tarantula not pose a threat, whether a choking hazard, or getting fingers, hair, jewelry, etc, caught in its moving parts, or being struck by the tarantula if it ran too fast. The user would also expect the tarantula to use standard-size batteries, preferably inexpensive, as well as have a long battery life, for multiple or extended use. The batteries should be secure, yet easy to replace if frequency was required. | ||
+ | |||
+ | ===User Research=== | ||
+ | In talking to users and allowing users to interact with the tarantula, the above three tenets were commonly raised in some form. Users frequently asked if the tarantula could survive a fall from a table, what directions it could move in, how fast it could run, and how far or how well concealed could the remote be, while still allowing the tarantula to operate. | ||
+ | |||
+ | ===Target Audience=== | ||
+ | It is clear from the packaging that scaring other people is the primary function. The ‘creepy’ aspects of the product are focused on. The ‘realism’ of the product is also heavily advertised, although the educational value of the product is dubious. The product is largely targeted to a youth demographic, as it falls under the purvey of ‘toy,’ however, all ages appear to enjoy the product, due to its novelty. | ||
+ | |||
+ | |||
+ | |||
+ | The following table summarizes the highest ranking customer needs, and product requirements. | ||
+ | {| class="wikitable" border="1" | ||
+ | |- | ||
+ | ! Rank !! Customer Needs !! Product Requirements | ||
+ | |- | ||
+ | ! 1 | ||
+ | | Realism || Durability | ||
+ | |- | ||
+ | ! 2 | ||
+ | | Ease of Use || Realism | ||
+ | |- | ||
+ | ! 3 | ||
+ | | Durability || Ease of Use | ||
+ | |} | ||
+ | |||
==Stakeholders== | ==Stakeholders== | ||
Revision as of 01:47, 24 September 2007
Contents |
Executive summary
Customer needs
The Tarantula is designed primarily as a form of entertainment for its user, and to a lesser degree, as an educational tool.
Users of this product seek out the novelty of a seemingly ‘alive’, self-contained creature, that they in turn are able to manipulate and direct, remotely. They may use it to observe the walking behavior of a simulated tarantula; more likely, they may use it to scare other people.
To this end, the user would require that the tarantula be durable, realistic, and easy to operate.
Durability
Ideally, the tarantula would be able to durable enough to function in different environments: indoors, outdoors, and on a variety of surfaces, including carpets and tile. The tarantula may be placed in an elevated location and then drop; therefore, the tarantula should be able to survive falls. The tarantula would also be frequently exposed to a younger audience, so it would need to survive pulling, tugging, tosses, and possibly even being struck or chewed on.
Realism
In order to convince other people that the tarantula is alive – even momentarily – the user requires a certain degree of realism. The user would want the tarantula to appear physically realistic, therefore it should be of the same size, color and texture as a generic ‘tarantula,’ or specifically, what the general population believes a tarantula to resemble. The user would also want the tarantula to have a realistic motion – its individual legs should move in a similar fashion to a real arachnid. The user would want the arachnid to not make a lot of noise – mechanical whirring would be a clear giveaway. Because a typical human being can easily cross a room in several seconds, the tarantula should be somewhat fast in its mobility. The goal would not be to outrun a person, necessarily, but to be able to encroach a person very quickly.
Ease of Use
Finally, the tarantula should be easy to operate. The user expects it to operate in a similar fashion to motor vehicles or other RC cars – in that navigating should be easy. The remote control’s buttons should be few and clearly labeled. The user would not expect to be required to articulate each individual leg, for example. Supervising adults would require that the tarantula not pose a threat, whether a choking hazard, or getting fingers, hair, jewelry, etc, caught in its moving parts, or being struck by the tarantula if it ran too fast. The user would also expect the tarantula to use standard-size batteries, preferably inexpensive, as well as have a long battery life, for multiple or extended use. The batteries should be secure, yet easy to replace if frequency was required.
User Research
In talking to users and allowing users to interact with the tarantula, the above three tenets were commonly raised in some form. Users frequently asked if the tarantula could survive a fall from a table, what directions it could move in, how fast it could run, and how far or how well concealed could the remote be, while still allowing the tarantula to operate.
Target Audience
It is clear from the packaging that scaring other people is the primary function. The ‘creepy’ aspects of the product are focused on. The ‘realism’ of the product is also heavily advertised, although the educational value of the product is dubious. The product is largely targeted to a youth demographic, as it falls under the purvey of ‘toy,’ however, all ages appear to enjoy the product, due to its novelty.
The following table summarizes the highest ranking customer needs, and product requirements.
Rank | Customer Needs | Product Requirements |
---|---|---|
1 | Realism | Durability |
2 | Ease of Use | Realism |
3 | Durability | Ease of Use |
Stakeholders
The stakeholders for this product are defined as entities that are involved at any of the stages of the product life cycle. All of these entities have an economic investment in the product. This includes the end user, as well as the suppliers of the raw material and components necessary to manufacture the finished product.
- Users
- Designers
- Suppliers (Plastic components, electrical assemblies)
- Manufacturers (Toy production/assembly)
- Distributors (Retailers, novelty specialty stores)
Function
The Tarantula is a variant of commonly seen remote controlled toys. The user holds a controller which sends radio signals to the Tarantula and controls its movement. The appeal of this toy is the novelty of a large moving spider as a remote controlled vehicle. Also, the realism of the device adds to the user’s enjoyment by allowing him or her to scare others with it.
Forward Locomotion
The controller only has two outputs, forward and back. During “forward” the motor runs in a clockwise direction engaging the drive wheels through a gear system. The drive wheels are under the head of the spider, and pivot to steer. A second set of wheels attached to the battery cover support the abdomen of the spider, but do not contribute to steering or propulsion. The drive wheels are vertically offset from each other to mimic a “crawling” motion and add to the realism. Due to the high gear ratio, the movement is slower than most RC toys, similar to what one would expect of an actual spider. However, the toy only functions well on very flat surfaces, and will become stuck on carpet or small obstacles.
Leg Movement
When the motor is engaged, a turn table in the head of the spider also spins. This table is cam shaped which causes it to asymmetrically engage 8 levers which are connected to the 8 legs of the spider. As the turn table engages the legs they are lifted up, but pulled back down by gravity as the turn table disengages them. This up and down motion of the legs mimics the crawling of a spider and it is central to the realism and novelty of the product.
Turning
The spider has no specific steering input form the remote control; rather it turns when the motor is running counterclockwise or receiving a “backwards” input. The drive wheels are setup such that depending on the direction the motor is running, the wheels will align to a certain orientation. The drive shaft for the wheels descends vertically from the head of the spider and connects to the drive wheels at a 90° angle. The bracket which holds the axle sits in two slots which allow it to rotate along the axis of the drive shaft. When the motor runs there is a net torque on the drive wheel axle, causing the bracket and axle to rotate if they are able. The wheels turn 45° relative to the centerline of the Tarantula if the motor is running backwards, and point straight ahead if the motor is running forwards. This causes the spider to turn while it is moving backwards, allowing the user to control the eventual destination of the device.
Power Train
The spider is powered by two AAA batteries connected in series. This powers the small motor and electronics (circuit board, LED eyes). The motor is connected to a gearing system with a large gearing ratio by a worm gear. This results in a slower movement, but higher torque on the drive wheels.
Product use
Components
Part # | Part name | QTY | Function | Materials | Manufacturing Process | Picture |
---|---|---|---|---|---|---|
001 | Cover Screws | 13 |
| Steel | Cold headed, Thread Rolled | |
002 | Inner Flat-headed screw | 2 |
| Steel | Cold headed, Thread rolled | |
003 | Battery Cover | 1 |
| Plastic | Injection Molded, hand modified | |
004 | Back Wheel housing | 1 |
| Plastic | Injection Molded | |
005 | Back Wheel | 2 |
| Plastic | Injection Molded, smoothed | |
006 | Small Leg | 4 |
| Plastic | Injection Molded | |
007 | Medium Leg | 2 |
| Plastic | Injection Molded | |
008 | Large leg | 2 |
| Plastic | Injection Molded | |
009 | Feelers | 2 |
| Plastic | Injection Molded | |
010 | Driving Wheel 1 | 1 |
| Plastic | Injection Molded, smoothed | |
011 | Driving Wheel 2 | 1 |
| Plastic | Injection Molded, smoothed | |
012 | Plastic Protection housing | 1 |
| Plastic | Injection Molded | |
013 | Back Wheel Axle | 2 |
| Steel | Cut wire, smoothed | Image:RC Tarantula Part 013.jpg |
014 | Battery Cover Washer | 1 |
| Plastic | Punched | Image:RC Tarantula Part 014.jpg |
015 | Gear 1 | 2 |
| Plastic | Injection Molded | |
016 | Gear 2 | 1 |
| Plastic | Injection Molded | |
017 | Gear 3 | 2 |
| Plastic | Injection Molded | |
018 | Gear 4 | 1 |
| Plastic | Injection Molded | |
019 | Axle 1 | 1 |
| Steel | Cut wire, smoothed | |
020 | Axle 2 | 1 |
| Steel | Cut wire, smoothed | |
021 | Axle 3 | 1 |
| Steel | Cut wire, smoothed | |
022 | Axle 4 | 1 |
| Steel | Cut wire, smoothed, stamped rough areas | |
023 | Axle 5 | 1 |
| Steel | Cut wire, smoothed, stamped rough areas | |
024 | Axle Cap | 1 |
| Plastic | Injection Molded | Image:RC Tarantula Part 024.jpg |
025 | Switch Assembly | 1 |
| Circuit Board (silicon), metal wires, plastic switch | Assembly | |
026 | Switch Cover | 1 |
| Plastic | Injection Molded | |
027 | Motor Assembly | 1 |
| Metal wiring, magnets, Metal casing, plastic gearing | Assembly | |
028 | Circuit Board Assembly | 1 |
| Circuit Board (silicon), metal wires | Assembly | |
029 | LED Assembly | 1 |
| Circuit (silicon), metal wires, LED | Assembly | |
030 | Tarantula exterior bottom | 1 |
| Plastic | Injection Molded, hand modified | |
031 | Tarantula exterior top | 1 |
| Plastic | Injection Molded, hand modified | |
032 | Battery Connector | 1 |
| Steel | Cut sheet metal | Image:RC Tarantula Part 032.jpg |
033 | Battery + connector | 1 |
| Steel | Cut sheet metal | Image:RC Tarantula Part 033.jpg |
034 | Battery - connector | 1 |
| Steel | Cut sheet metal | Image:RC Tarantula Part 034.jpg |
035 | Metal screw receiver | 1 |
| Steel | threaded cylinder | Image:RC Tarantula Part 035.jpg |
036 | Drive Wheel Mount | 1 |
| Plastic | Injection Molded |
Design for manufacturing and assembly
Failure mode effects analysis
Item & Function | Potential failure mode | Potential failure effects | SEV | Potential causes | OCC | Design controls | DET | RPN | Actions recommended | Respons ibility | Actions Taken | New SEV | New OCC | New DET | New RPN |
Internal Electronics Components | Wiring Disconnect |
| 8 |
| 4 |
| 6 | 192 |
| N/A | N/A | 6 | 2 | 6 | 72 |
Power Train | Wearing of gears or motor. Loose mounting allowing for vibration. |
| 4 |
| 5 |
| 6 | 120 |
| N/A | N/A | 4 | 3 | 6 | 72 |
Gears | Gear slip |
| 6 |
| 4 | Textured axels. Quality controls of gear supply and positioning. | 5 | 120 |
| N/A | N/A | 6 | 2 | 5 | 60 |
Motor | Overheating resulting in seize |
| 7 |
| 3 |
| 5 | 105 |
| N/A | N/A | 7 | 2 | 5 | 70 |
Internal Electronics Components | Short circuit |
| 7 |
| 5 |
| 3 | 105 |
| N/A | N/A | 6 | 2 | 3 | 36 |
Drive Wheel Mount | Mount is unable to pivot |
| 6 |
| 4 |
| 4 | 96 |
| N/A | N/A | 6 | 2 | 4 | 48 |
Hair Covering | Flaking of hair off of body |
| 3 |
| 10 |
| 3 | 90 |
| N/A | N/A | 3 | 5 | 3 | 45 |
Remote Control | Interference with other RC devices |
| 5 |
| 8 |
| 2 | 80 |
| N/A | N/A | 5 | 2 | 2 | 20 |
Legs | Legs become fixed in a single position |
| 4 |
| 5 |
| 3 | 60 |
| N/A | N/A | 4 | 3 | 3 | 36 |
LED Eyes | LED eyes become dim, asymmetrical or unlit |
| 3 |
| 6 |
| 3 | 54 |
| N/A | N/A | 3 | 4 | 3 | 36 |
Design for environment
EIOLCA
The amount of environmental impact attributable to a single Tarantula is relatively negligible. But when the large volume of numbers produced is taken into account, the amount of pollutant emissions, economic demands, and energy needs become a larger factor to consider. The apparently environmentally harmless product becomes more a larger problem when considered in the grander scale of manufacturing and production.
The method used to calculate the environmental and economic impact of the Tarantula involves the use of data provided through the Economic Input-Output Life Cycle Assessment (EIO-LCA) database. In order to get a proper appreciation of the impact of the product, all calculations and measurements are done in terms of millions of dollars of economic activity. The database compiles information pertaining to the economic demands, pollutants emitted, energy demands, even the labor needs for certain sectors of different industries. Once a sector’s impact is calculated, the information pertaining to the contributing factors for each million dollars of activity can be accessed and compared.
Production of the Tarantula pertains primarily to sector 33930 - Dolls, Toys, and Game Manufacturing. However, over the lifetime of the product’s use, multiple purchases of batteries are required. As a result, the economic and environmental impact of the product is also linked to sector 335912 - Primary Battery Manufacturing. The focus of this analysis is to observe the main sources of emissions and demand for energy. The types of emissions observed are greenhouse gases, conventional air pollutants, and toxic releases.
For sector 33930, the primary consumer of energy is power generation itself. It consumes nearly three times the energy as the next two sectors, which are toy manufacturing and paperboard mills. These three sectors combined contribute for approximately half of the total energy required, amounting to 3.99 TJ/$1 Million for Production. The non-toxic emissions produced are also primarily attributable to power generation.
However, the toxic releases caused by sector 33930 are attributable to the nature of the type of manufacturing methods required. Plastics material manufacturing is a vital factor necessary for the production of dolls, toys, and games. Of the 46.4kg/$1M, approximately 20 kg is caused by toy manufacturing and plastics material manufacturing. Additionally, the dependence upon the use of batteries over the lifetime of the product requires an analysis of the toxic releases of sector 335912. Due to the nature of battery production, inorganic chemical manufacturing is required. Inorganic chemical manufacturing contributes a significant portion of the total toxic emissions caused by battery production. With this in mind, a possible course of action for product improvement would be to decrease the amount of batteries consumed over the product life cycle.
Toxic Releases
The contributing sectors primarily to Toxic Releases for sector 33930 Doll, Toy and Game Manufacturing are:
- 325211 Plastics material and resin manufacturing
- 331112 Ferroalloy and related product manufacturing
- 325190 Other basic organic chemical manufacturing
- 325110 Petrochemical manufacturing
When factoring in the reliance on battery usage over the lifetime of the product, considerations must be made. The end-life status of the batteries is the main concern for our study. The corresponding sectors that contribute to sector 335912 Toxic Releases are:
- 325180 Other basic inorganic chemical manufacturing
- 326290 Other rubber product manufacturing
- 331492 Secondary processing of other nonferrous
- 325190 Other basic organic chemical manufacturing