Talk:Baby stroller
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| + | Client Comments on Report= | ||
| + | We received your [http://ddl.me.cmu.edu/ddwiki/index.php?title=Baby_stroller&oldid=16641 report]. Your main conclusions seem to be that the stroller is already well designed, and the specific opportunities you see are to change the fabric/frame connection and increase structural stability of the tray to reduce failure potential. You mention that your FEA analysis predicts a 17cm deflection of the tray when lifted - does this match your physical observations? We look forward to seeing your research findings and new ideas in the next report. | ||
| + | |||
| + | Detailed comments follow: | ||
| + | # Your bill of materials has no introduction - what are your main findings? | ||
| + | # It seems that you did not disassemble the product down to individual components. Although you may have chosen due to budget limitations not to separate subassemblies that require destruction to separate (which is not ideal), it is important that you still identify all individual components with clear pictures highlighting each separate component and identifying manufacturing operations. For instance, part 1 appears to be two components, parts 5, 9-10 are difficult to identify, and the frame and seatbelt subassemblies are not identified by individual components. Part F1 also appears to be two parts. | ||
| + | # Your usability descriptions are interesting, but it would be easier to understand with pictures - particularly to show folding and locking of the stroller. What happens if the handle is dropped while folding the stroller? Is it necessary for the user to bend down to the ground? The gear mechanism that locks the wheels is not documented elsewhere. The difference between wheels "turning" and "rotating" should be clarified. | ||
| + | # You have identified some important stakeholders and needs, but some important ones appear to be missing, including easy to store, maneuverable, portable, light weight, stable, etc. The space constraints may also play different roles in storage vs. use (e.g.: fitting in a checkout aisle). Please expand on these. | ||
| + | # In your functionality section, you describe how the user interacts with various aspect of the stroller, but you do not show how these mechanisms actually work. In particular, the folding mechanism, seatbelt mechanism, and wheel locking mechanism need more explanation. | ||
| + | # What scales are you using for your FMEA numbers? | ||
| + | # Your DFMA seems to conclude that there are no opportunities for improvement? Are DFM guidelines followed well? Are the DFA operations really as easy as you claim? For example, do the riveting operations on the frame require a special fixture to hold the tubes in place while fastening? Are there intermediate parts at rotating joints that must be held in place? You mention that the assembly has a logical order, but you don't discuss any specifics about what that order would be or what makes it logical. | ||
| + | # We were disappointed to find a range of grammatical and spelling errors and incomplete sections in the text (for example, the text "part#" appears instead of true part numbers, "additional futures for the stroller", "There are Things fit", etc. Please be sure to proofread any future reports for clarity and professionalism. | ||
| + | # Why does the "nature of the product" require that customers assemble certain parts themselves? | ||
| + | # You mention that tolerances were chosen to "avoid necessary tight precisions". We assume you mean "avoid unnecessarily tight tolerances", but what are specific examples? | ||
| + | # In your LCA, does the doll and toy sector include stroller manufacturing? Is the sector representative? You mention that reduction of impact would mostly be through more efficient transportation, which is outside of our control, but how do the product decisions affect transportation efficiency? How do you conclude that energy used to recycle the product is less than energy needed to manufacture from raw materials? You seem to confuse waste management related to manufacturing with waste management at the product's end of life. Please comment. | ||
| + | # In your mechanical analysis, why did you choose a 40 lb load? How does your deflection compare to observation of the real product? | ||
| + | |||
==Client comments on the Mechanical Analysis== | ==Client comments on the Mechanical Analysis== | ||
This is a useful analysis to know the possible deformation of the plastic tray. My comments are listed in follows: | This is a useful analysis to know the possible deformation of the plastic tray. My comments are listed in follows: | ||
Revision as of 13:44, 30 September 2008
Client Comments on Report= We received your report. Your main conclusions seem to be that the stroller is already well designed, and the specific opportunities you see are to change the fabric/frame connection and increase structural stability of the tray to reduce failure potential. You mention that your FEA analysis predicts a 17cm deflection of the tray when lifted - does this match your physical observations? We look forward to seeing your research findings and new ideas in the next report.
Detailed comments follow:
- Your bill of materials has no introduction - what are your main findings?
- It seems that you did not disassemble the product down to individual components. Although you may have chosen due to budget limitations not to separate subassemblies that require destruction to separate (which is not ideal), it is important that you still identify all individual components with clear pictures highlighting each separate component and identifying manufacturing operations. For instance, part 1 appears to be two components, parts 5, 9-10 are difficult to identify, and the frame and seatbelt subassemblies are not identified by individual components. Part F1 also appears to be two parts.
- Your usability descriptions are interesting, but it would be easier to understand with pictures - particularly to show folding and locking of the stroller. What happens if the handle is dropped while folding the stroller? Is it necessary for the user to bend down to the ground? The gear mechanism that locks the wheels is not documented elsewhere. The difference between wheels "turning" and "rotating" should be clarified.
- You have identified some important stakeholders and needs, but some important ones appear to be missing, including easy to store, maneuverable, portable, light weight, stable, etc. The space constraints may also play different roles in storage vs. use (e.g.: fitting in a checkout aisle). Please expand on these.
- In your functionality section, you describe how the user interacts with various aspect of the stroller, but you do not show how these mechanisms actually work. In particular, the folding mechanism, seatbelt mechanism, and wheel locking mechanism need more explanation.
- What scales are you using for your FMEA numbers?
- Your DFMA seems to conclude that there are no opportunities for improvement? Are DFM guidelines followed well? Are the DFA operations really as easy as you claim? For example, do the riveting operations on the frame require a special fixture to hold the tubes in place while fastening? Are there intermediate parts at rotating joints that must be held in place? You mention that the assembly has a logical order, but you don't discuss any specifics about what that order would be or what makes it logical.
- We were disappointed to find a range of grammatical and spelling errors and incomplete sections in the text (for example, the text "part#" appears instead of true part numbers, "additional futures for the stroller", "There are Things fit", etc. Please be sure to proofread any future reports for clarity and professionalism.
- Why does the "nature of the product" require that customers assemble certain parts themselves?
- You mention that tolerances were chosen to "avoid necessary tight precisions". We assume you mean "avoid unnecessarily tight tolerances", but what are specific examples?
- In your LCA, does the doll and toy sector include stroller manufacturing? Is the sector representative? You mention that reduction of impact would mostly be through more efficient transportation, which is outside of our control, but how do the product decisions affect transportation efficiency? How do you conclude that energy used to recycle the product is less than energy needed to manufacture from raw materials? You seem to confuse waste management related to manufacturing with waste management at the product's end of life. Please comment.
- In your mechanical analysis, why did you choose a 40 lb load? How does your deflection compare to observation of the real product?
Client comments on the Mechanical Analysis
This is a useful analysis to know the possible deformation of the plastic tray. My comments are listed in follows:
- Please list your ABS material property settings (e.g. tensile strength, Young’s modulus and Poisson’s ratio) used in the finite element analysis and indicate the reference for the values.
- Please verify that the assumption of 20 lb is large enough to cover the weight of whole stroller and a baby setting in it. A scenario may often occur when a user holds the front edge of the tray and the rear handle to lift the whole stroller for going up/down stairs. The assumed force should represent this possible maximum force applied to the tray.
- Is the simulation result closed to the real displacement? The real tray has round fringes, which actually increases the structural strength of the tray. This point should be included in your discussion.
