Talk:Ratcheting screwdriver

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We received your [http://ddl.me.cmu.edu/ddwiki/index.php?title=Ratcheting_screwdriver&oldid=9801 report], and you have some interesting results, but we would like to see more detail specific to your design and more clear findings and conclusions. Comments follow:
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We received your [http://ddl.me.cmu.edu/ddwiki/index.php?title=Ratcheting_screwdriver&oldid=9801 report], and you have some interesting findings, but we would like to see more detail in some areas. Comments follow:
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* Executive summary is quite vague and generic. What are your findings and conclusions?
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* Please include a picture of the product
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* Customer needs - should consider things such as ability to carry up and down stairs, noise, ability to clean alternative surfaces, etc.
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* Nice executive summary your findings are clear.
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* The description of product function is cursory. Please explain in more detail the mechanical function for your specific product. A figure would help.
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* Explanation of product function is rather clear, but figures would help. It is difficult to imagine the packaging of the mechanism without documentation.
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* It is unlikely that your screws are cast. Do you see evidence of casting?
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* The customer use description is fine, but a more detailed account of the procedure would be useful.
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* It appears that you did not take the disassembly entirely down to individual components. For example, part #A-008 appears to be an assembly, rather than a single injection molded part. Please reexamine and clarify.
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* The DFMA is detailed. A summary of findings before including the list of data would be helpful.
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* Your FMEA is just a table. What are your conclusions. We typically do not expect to see raw data without explanation or conclusion in a professional report.
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* The LCA is interesting, but a change to nuclear power is far beyond our scope. More detail on your analysis would be helpful – which sectors did you use to represent ratcheting screwdriver manufacturing? Does use phase or manufacturing dominate the drill impact?
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* Your LCA is interesting, but the link to results does not function. You seem to conclude that impact from the use phase is greater than from manufacturing. Is this on the basis of GHGs? Should we focus on redesigning the product for reduced energy use?
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* The FMEA appears to be just a data table with no discussion. What are we supposed to do with this? How will stronger metal reduce failure from the dead battery pack?
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* It is difficult to follow the component air flow in your air flow analysis. Relating to an assembly figure would help. You seem to throw a few generic equations around, but what are the numbers for this design, and what do they tell you?
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* Some pictures appear to be missing from the parts list, and some pictures include multiple components without identification of the component in study. Also, your parts list includes only one sun gear and one planet gear, but there seem to be more. Why would copper be selected for the gears? Please reexamine.
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* The gear analysis is clear – so is the 0.011 gear ratio the right ratio for the drill? What can you conclude?
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**The mechanical analysis of the gear train has been expanded to include an overall conclusion of this gear ratio.
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* It is difficult to follow your analysis of the pawl without a diagram. Is the pawl the most likely point of failure, or would it be the ratchet wheel? Is the resulting failure torque of 23 N-m reasonable? What factor of safety does it give for the most extreme working conditions you might expect?
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**The mechanical analysis of the pawl has be redone within the report, including diagrams explaining parts of the analysis.

Current revision

We received your report, and you have some interesting findings, but we would like to see more detail in some areas. Comments follow:

  • Please include a picture of the product
  • Nice executive summary – your findings are clear.
  • Explanation of product function is rather clear, but figures would help. It is difficult to imagine the packaging of the mechanism without documentation.
  • The customer use description is fine, but a more detailed account of the procedure would be useful.
  • The DFMA is detailed. A summary of findings before including the list of data would be helpful.
  • The LCA is interesting, but a change to nuclear power is far beyond our scope. More detail on your analysis would be helpful – which sectors did you use to represent ratcheting screwdriver manufacturing? Does use phase or manufacturing dominate the drill impact?
  • The FMEA appears to be just a data table with no discussion. What are we supposed to do with this? How will stronger metal reduce failure from the dead battery pack?
  • Some pictures appear to be missing from the parts list, and some pictures include multiple components without identification of the component in study. Also, your parts list includes only one sun gear and one planet gear, but there seem to be more. Why would copper be selected for the gears? Please reexamine.
  • The gear analysis is clear – so is the 0.011 gear ratio the right ratio for the drill? What can you conclude?
    • The mechanical analysis of the gear train has been expanded to include an overall conclusion of this gear ratio.
  • It is difficult to follow your analysis of the pawl without a diagram. Is the pawl the most likely point of failure, or would it be the ratchet wheel? Is the resulting failure torque of 23 N-m reasonable? What factor of safety does it give for the most extreme working conditions you might expect?
    • The mechanical analysis of the pawl has be redone within the report, including diagrams explaining parts of the analysis.
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