Laptop chill pad
From DDL Wiki
We have completed a preliminary design study of the Logitech Cooling Pad N200. Initially, group discussions included problems with the existing model as well as possible and feasible improvements. With these in mind, we conducted a product dissection study. Our analysis of the design consisted of four approaches: design for manufacturing, design for assembly, failure modes and effects, and design for environment.
After conducting the design analysis for manufacturing and assembly, we can conclude that for the most part, the product has been designed for efficient manufacturing and assembly. Few possible design improvements linger, but determining their actual effectiveness will require further study on product use and specific manufacturing and assembly methods.
Our design for environment analysis showed that the production of our product would result in a minuscule CO2 tax, less than 2% of the retail value. Nearly 90% of our greenhouse gas emissions came from the laptop manufacturing and electricity production. Our product saves the user from replacing their laptop battery once throughout the product's lifespan which would cause the CO2 tax to be lowered.
Failure modes and effects analysis showed that the product is not likely to experience severe, commonly occurring and difficult to detect modes of failure. The biggest concerns are with the USB cord, specifically a break in the inner wires. Introducing a retractable element to the pad design would leaving no slack in the cord, lowering the occurrence of this failure. In general though, most failures can be fixed with simple design changes, allowing us to focus more on environmental and cost considerations.
After conducting the design analysis, we concluded that the product was designed to optimize manufacturing and assembly. We decided that our design would be more focused on the product performance than on the manufacturing and assembly aspect. Our improvements are going to focus mostly on the usage phase. Improving product performance would have a significant effect on the battery life.
There are four stake holders for the chill pad: the customer, the retailer, the manufacturer, and the shipper.
The primary consumers for chill pads are users who intensively use their laptops such as gamers and most college students. College students are much more likely to have laptop computers and laptops typically overheat when the user is playing games. Because the chill pad would be used mostly in dormitory settings, portability is not a main priority. Rather, durability and effectiveness are more important for the target consumer.
- Relatively cheap- under $50
- Life span- 3-4 years
- Effective cooling
- Less noise than computer
- Multi-surface use
- Effective fan mobility/placement
- Portability (semi)
- Well designed
- Good ergonomics
- Easy powering option (usb or battery or plug in wall)
- Adjustable power settings
- Low weight
- Adaptability to laptop size
- Manageable Size
The primary retailers are those who directly sell the product to consumers, varying from electronic stores to online retailers. They can be identified as stores that primarily sell technology-related products. These stores would prefer a slick design as well as product performance to attract younger, more tech savvy consumers.
- Good presentation
- Outstanding performance
- Good yet cheap material
- Less custom parts
- Easy to replace parts
Manufacturers are responsible for mass production of products. Therefore they would value low production costs.This means lower costs for raw materials, simple assembly, among others.
- Low production cost
- Fewer parts
- Parts with simple molds
- Less materials
- Common materials
- Cheap materials
- Easy to work with materials
- Low assembly time
Shipping/transport stakeholders are primarily commercial delivery companies. They would benefit from lighter, easily packaged products, and small manageable packages.
- Durable product
- Small and durable packaging
- Low weight
Different chill pads have variations in their use. However the basic steps are as follows:
1. Place chill pad on surface
2. Place laptop on chill pad
3. Plug chill pad into laptop
The specific steps for the N200 Chill Pad were as follows:
These are the instructions for another chill pad that we tested.
An experiment was conducted that assessed the effects of the chill pad on the temperature of a laptop. The stages of the experiment are as follows:
1.Ran several programs on a computer(SolidWorks, a graphic-intensive game, and youtube video) with the chill pad on (apprx 12 mins)
2.Continued running same programs on computer with chill pad off (apprx 8 mins)
3.Continued running same programs on laptop with chill pad on (apprx 3 mins)
The temperatures of the internal components (core 1 and 2 of a dual core computer processor) were measured during these three phases, and the results are graphed below:
The laptop had many programs running simultaneously which in turn increased the temperature within the laptop. After reaching the steady state without the chill pad, the chill pad was then turned on. The chill pad had a significant role in cooling the laptop because after the chill pad was turned on, the temperature of the cores on the computer dropped 20 degrees.
This table shows the results of high temperature on batteries. As can be seen, subjecting the laptop to high temperatures significantly and permanently decreases the battery life. During high activity, laptop interiors can reach temperatures up to 180 degrees Fahrenheit.
Design For Manufacturing and Assembly
Design for Manufacturing
The competitor’s product has been designed well with respect to manufacturability, especially in high volumes. The product has a low complexity as well as a part count that matches its level of complexity. All of the plastic parts are injection molded and have been designed well with respect to their manufacturing process. For instance, each part has uniform wall thickness and has ribs and other strengthening features with good dimensions. In addition, the manufacturer made new parts for parts with different geometry in order to keep the molds simple. Another good feature is that the coloring of parts can be incorporated into the molding process, thereby cutting down on the steps needed to manufacture the product. Once the parts are molded, they do not need secondary operations, except for painting on the Logitech logo on the front of the chillpad.
Another well designed aspect is the use of rubber spacers in between the top and bottom cover. One of its main uses is that it allows for lower requirements on tolerance of the molds, thus making the molds cheaper.
The most number of parts comes from the number of screws. Although this could be lowered by changing from screws to a molded in, snap-fit feature, using screws allows the part to be assembled easier, allows for the ability to open the product without breaking it, and keeps the mold simpler and cheaper. However, instead of having different screws, the screws can be standardized for all uses.
In summary, the competitor’s product has been designed well for manufacturing and there is little room for improvement in this area.
- Relatively low part number and simple parts
- Mostly all parts injection molded
- Plastic material, easy to work with
- allows color to be built in, instead of painting
- Parts designed well for molding: same wall thicknesses, ribs and strengthening features are good dimensions
- Areas of the part with different geometries were made into different parts,
- To keep mold simple
- Used rubber stoppers between parts to account for tolerances
- Lower tolerance allowed
Areas of Improvements
- Different screws, standardize them
Design for Assembly
Although the design for assembly can be improved on, most aspects of the design have been optimized to enable an easy, cheap assembly process. As for major improvements, the fan containment shell could be joined with the bottom body piece as one piece. There could be certain problems regarding the manufacturing process, but it would improve the design for assembly. In addition, the fan and shell casing components could be a subassembly that could be manufactured separately. The Logitech logo piece is unnecessary and just adds to the complexity of the assembly. Lastly, joining the felt to the bottom piece provides an assembly complexity as it may require multiple assembly directions or manual assembly. As for minor improvements, screws could be replaced with snap-fit designs and the screws necessary could be standardized. As for the current design, the elastic spacers between two parts are a useful inclusion for variable manufacturing tolerances. Another noteworthy design decision was the fan subassembly. The fan component contained a circular magnet, and it rested over a chip with four copper coils, a simple electrical motor with no rotating shafts or additional components to bog down the assembly and manufacturing processes. The general assembly process seems unambiguous and the assembly surfaces are kept to a decent minimum.
- Assembly directionality is mostly unambiguous and simple
- Fan subassembly is designed to function without rotating shaft
- Elastic spacers are used to fit pieces with variable manufacturing tolerances
Areas of Improvement
- Fan and casing could be subassembly
- Rubber Logitech piece is unnecessary and just adds to manufacturing and assembly complexity
- Attaching felt onto plastic piece provides assembly complexity
FMEA (Failure Mode and Effects Analysis)
|Failure Modes and Effects Analysis - Laptop Chill Pad|
|Items and Function||Failure Mode||Effects of Failure||Severity||Causes of Failure||Probability of Occurrence||Design Control||Detectability||RPN||Recommended Actions|
|Fan - cools laptop||Fan blades break off||Laptop heats up||6||Dent/Other Defect Causes Fan to Collide with Casing||1||Tolerance Testing on Fan/Casing||3||18||Keep Injection Mold Simple to Avoid Defects|
|Fan stops spinning||7||Fatigue, Loss of Power from Motor||1||Fatigue Testing of Fan||1||7||Choose Material to Meet Needs|
|USB - Provides Power||Disconnection||Loss of power to chill pad||2||Loose Port, Something Snags Cord||7||None||1||14||Entertain options for compact cord wrapping|
|Broken inner wires||Loss of functionality||6||Damage to cord||2||3||36||None (Out of Designer Control)|
|Bend on connector||Connector could break off inside laptop||7||Bumping Connector While Inside Port||2||1||14|
|Power diverted elsewhere||Lower performance of chill pad||2||Too Much Usage from Programs||3||3||18||Keep Software to Low Power Usage Specs|
|Casing - Protects fan||Fan blades break off||Laptop heats up||6||Dent/Other Defect Causes Fan to Collide with Casing||1||Tolerance Testing on Fan/Casing||3||18||Keep Injection Mold Simple to Avoid Defects|
|Motor - Drives Fan||Fatigue||Stops rotating fan||6||Electrical Problem, Demagnetization||1||Cyclic Testing of Motor||3||18||Entertain Different Motor Configurations|
|Air Intake - Allows Air to Enter Through Bottom||Allowance of More than Air to Get Through Fan||Lower fan performance, Possible damage fan||3||Over-sized openings||3||Testing with Dust/Debris Under Chill Pad||2||18||Reduce Hole Size|
|Mechanism Holding USB Cord Breaks||No convenient storage of for USB Cord||3||Broken(Yielded) Tabs||3||Cyclic testing of tabs||2||18||Retractable USB Cord|
|Grill - Allows Air Through Top||Particles slipping through grill||Possible damage to fan||3||Over-sized openings, Damaged grill||2||Strength testing of grill||2||12||Change Angle of Grill, or Use Different Cooling Method|
|Screws - Holds Assembly Together||Loosening||Assembly falling apart||4||Overuse, Fatigue||2||Testing of regular use||3||24||None (Out of Designer Control)|
|Rubber stoppers - Stops the computer from slipping||Disconnects from grill||Laptop slips off chill pad||4||Overuse, designed too loosely||3||Load and cyclic testing on stoppers||2||24||Put stronger grips on rubber stopper or adhere them differently|
|Rubber spacers - Pushes apart the top and bottom cover||Rubber tears||Top and bottom are not tightly connected everywhere||4||Overuse, weak rubber material||2||Cyclic testing on the assembly with spacers||4||32||Add more support to lessen the load on each spacer|
Across the board, the detectability scores for the device’s failure modes are very low, that is, anything that goes wrong with the device will be quickly and easily spotted by the user. The highest RPN value is associated with the mode of failure wherein the USB cord stops transmitting power due to damaged wires inside. This is a critical failure mode because it compromises the functionality of the whole device, the part is not easily replaceable, and USB wires are not typically very strong. To combat this potential failure, we propose a mechanism to retract the cord, which would avoid situations where slack in the cord makes it susceptible to damage. Another major concern from the analysis above is a tear in the rubber spacers between the top and bottom plates of the chill pad. More in depth analysis should be done to test whether the material of the rubber is strong enough to withstand overuse or if more support points should be added to better distribute the load. In general though, these failure modes have mostly low scores, and we do not expect them to get in the way of improving on the product’s design for cost effectiveness, lessening environmental impact, and other factors more constraining than failure mode analysis.
Design for Environment
As companies and engineers are becoming more aware of how their products impact the environment, consideration of this has been added to the product design process. As global warming becomes a more widely recognized fact, the reduction of greenhouses gas emissions has become important. With a possibility of a federal tax on the emissions of greenhouse gases($30/mt), it is necessary to conduct a study on how this tax would effect a laptop chill pad.
Using the EIOLCA model (See reference #3 at the bottom) we were able to determine an estimate on the total amount of CO2 the production phase of a laptop chill pad would produce. We ran the model using the small electrical appliance manufacturing sector(#335210) with an input of $1 million. As seen on the chart on the left 570mt of CO2 were emitted. Scaling this to the emissions for the manufacturing of a single laptop chill pad costing $40 we found that 0.0228mt of CO2 are released. A $30/mt tax would cost a company an additional $0.68 per laptop which is 1.7% the total cost.
An analysis of the economic activity shows that per $1 million spent on the retail value of the product, $2.18 million is spent in creating it.
There are two components that are used in conjunction with our product. The first and most obvious is a laptop that the chill pad is specifically designed for. The second component is the electricity that is needed to power the laptop while it is in use.
The CO2 emissions that are involved with the manufacturing of a laptop are needed. The EIOLCA model was used with an input of $1 million to determine the amount of CO2 emitted. For a laptop we choose to use the electronic computer manufacturing sector, #334111. A total of 284 mt of CO2 were produced and when scaled to the production of a single laptop(~$1000) we see that 0.28mt of CO2 are emitted. With a tax of $30/mt this equates to $8.52 or 0.852% the total cost.
The production of the electricity needed to power the laptop emits C02. As done previously the EIOLCA model is used per $1 million to compute an estimation. The power generation and supply sector, #221100, was run to determine that 9370mt of CO2 were emitted per $1 million. A few assumptions were made to determine the impact for the chill pad's life cycle:
1. An average laptop uses 70 watts per hour
2. An average user will use their laptop for 2.5 hours a day
3. The chill pad has a life cycle of 3 years.
4. 1 kWh costs $0.112 (See Reference #2)
Using these parameters we estimate that 191.625 kWh are consumed at a cost of $21.46. Thus per life cycle 0.2010802mt of CO2 are emitted at a cost of $6.03.
We assumed that a laptop battery lasts 1.5-3 years(See References #4 & #5) and thus the consumer would replace the battery once throughout the chill pad's lifespan. Analyzing the emissions in producing a single laptop battery shows that 0.05mt are emitted. With the CO2 tax this would equate to $1.56. However our analysis in the User Study section illustrates the chill pad has the potential to cool the laptop enough to allow the battery to last the duration of the chill pad's lifespan.
The summary for the analysis of the environmental impact from production and usage phases are displayed in the table below. The pie graph shows the breakdown of how each component contributes to the overall CO2 tax that we would incur. The important takeaway is that the production phase only accounts for $% of the total CO2 tax. The laptop manufacturing and electricity production account for the majority of the tax, combining for 87%. While the manufacturing of a laptop battery is only a tenth of the overall tax, it has the possibility to be negated. Early evidence shows that the chill pad has the possibility to keep the laptop at a cool enough temperature that it will extend the battery's lifespan. If this longer lifespan can last the duration of the chill pad's lifespan then the consumer would not have to purchase a new battery and would lower our CO2 tax.
Bill of Materials
The chill pad consists of five simple components: top cover, bottom cover, air intake, grill, and fan subassembly. The assembly is fairly straight forward. There are 16 parts we identified in the assembly. It consists mostly of plastic parts which were manufactured using different molding methods. Several metal screws were used to attach the components together. There are electrical components in the assembly that we did not disassemble such as the motor, switch and the USB connector. In the table below, the parts we identified are listed along with their properties and functions.
List of Components
|Part Number||Part Name||Quantity||Weight (g)||Material||Manufacturing Process||Function||Part Image|
|1||Top Cover||1||262.2||Plastic||Injection Molding||Connects to the top grill and bottom cover. Protects inner workings.|
|2||Top Grill||1||170||Plastic||Injection Molding||Connects to the top cover. Protects the fan and allows fan blown air to go through.|
|3||Screws||5||< 1||Steel||Purchased||Connects the top cover to the bottom cover.|
|4||Rubber Screws||4||.25||Rubber||Injection Molding||Connects the fan assembly to the top cover.|
|5||Fan Casing||1||16.5||Plastic||Injection Molding||Connects to the top cover and the fan.|
|6||Fan||1||25||Plastic||Injection Molding||Spins and blows air through the grill.|
|7||Motor||1||7.4||Various||Purchased||Connects to the fan. Spins the fan.|
|8||Felt||1||40||Felt||Purchased||Glued to the bottom cover. Provides soft interface between the user and product.|
|9||Bottom Cover||1||186||Plastic||Injection Molding||Connects to the top cover and protects the inner workings. Provides a base for the product.|
|10||Air Intake||1||81||Plastic||Injection Molding||Connects to the bottom cover. Allows air to flow into the chillpad.|
|11||Small Screws||3||< .1||Steel||Purchased||Connects the air intake to the top cover.|
|12||Rubber Spacers||4||.25 each||Rubber||Injection Molding||Pushes on the top and bottom cover to provide a space in between.|
|13||Removable Rubber Stoppers||2||12 each||Rubber||Injection Molding||Connects to the top grill. Provides increased friction between the laptop and chillpad to keep it from moving.|
|14||USB Connector||1||4.3||Various||Purchased||Connects the chillpad to the computer to draw power.|
|15||Switch||1||3.7||Plastic||Injection Molding, Assembled||Allows the user to control the fan speeds.|
|16||Wires||1||4.2||Copper||Purchased||Connects the motor to the switch and then to the USB Connector.|
|17||Logo Tab||1||2.3||Rubber||Injection Molding||Marketing purpases|
|18||Small Screw||2||< .1||Steel||Purchased||Attaches the logo tab to the chill pad|
The numbers coordinate with the part number in the bill of materials.
Team Member Roles
For coordinating the work, we had group meetings in which we all helped with high level brainstorming for all the parts of the analysis. After that, each group leader worked on on his respective area and would ask for the group help, if and when needed.
Phase I Team Roles
- Team Leader - James Chon
- DFMA(Assembly) Leader - Jay Kim
- DFMA(Manufacturing) Leader - Mukul Bhatt
- DFE Leader - David Gregor
- FMEA Leader - Brenden Patch