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Revision as of 18:03, 8 October 2009

Client Comments on Report 1

We received your report, and we have some comments and questions. It sounds like you have identified a few opportunities for improvement, including reducing likelihood of being cut, improving flexibility for alternative mounting directions, and improving the suction stability. Please respond point by point to the items below. We are looking forward to seeing your ideas in Report 2.

• Executive Summary: Nice overview of findings. Could be more concise - e.g.: no need to explain FMEA here.
  • HAHA
• Stakeholder Needs: Good initial list. Some needs appear to be missing, such as easy to clean and store, reliable, robustness to working on alternative work surfaces, etc.
• Use: Good description and observations. This product as a lot of potential areas for improvement. Is the product intended and/or used for any objects besides apples?
• Assembly: Clearly labeled.
• Mechanical Function: The report describes the steps the user takes and some observations about use, but there is no section describing how the peeling, slicing and coring actually takes place mechanically. A diagram or labeled picture would help. It is not clear how pressing the vacuum lever creates the suction.
• Mechanical Analysis:
  • What are the design implications of your analysis question and result?
  • How do you know that 40N applied to the handle is sufficient to peel an apple? Do these findings correspond to the experiences of the users?
  • Please define your notation and be consistent (P versus Pmax, r versus d). Also state where each equation comes from.
  • Your free body diagrams are somewhat confusing as the forces and pivot points seem to move around between the different diagrams. Please explain why they move and justify your assumptions of force and pivot point locations. You may consider simplifying the problem by modeling the suction cup as a pin instead of a cylinder.
  • Where do your numbers come from, in particular the mass? Is that the measured mass of your product? Does it include the mass of an apple?
  • You might need an additional free body diagram to show where you got the suction cup forces from.
  • Your sig figs (111.684N) suggest a level of precision that we are doubtful one could achieve.
• Bill of Materials: Good.
• DFMA: You say that paint is necessary to keep the aluminum parts from rusting? Although aluminum does oxidize, it does not rust like steel. Is there an increased risk because of contact with fruit juices? Please explain. Standardizing fasteners seems like a reasonable goal - are there any other relevant comments about DFA guidelines?
• FMEA: Good list. You only have one failure mode listed for "vacuum", which is simply labeled "failure". Is this due to deformation or use on a rough surface or hardening of the material or some other mode?
• DFE: Good observations. Do you think the sector you chose is sufficiently representative of the apple peeler? You did not answer our question about a CO2 tax. You say that the product is used by itself. We thought it was used with apples?
• If any of your images, figures, or text were taken from another source, please be certain to provide proper attribution.