From DDL Wiki

First Report

We received your report on the inkjet printer and were generally impressed with your work; although we found the documentation lacking in the completeness and professional format usually expected of a report. It is clear that you have done some interesting analysis, although we had a hard time following your logic on which areas you decided to focus and what your conclusions and recommendations are. Detailed comments follow:

• In our company (and in most companies that we know of) reports will contain an executive summary that typically outlines your conclusions, not just a summary of what topics will be discussed in the report. This would be helpful for us in the next report, since our executives typically do not have time to read the full report.
• Many of the aspects of the report appear to be only headings with bulleted lists, rather than a report. We are happy to see your bulleted lists, but we would normally expect to see a paragraph explaining each list and outlining conclusions of each section. For example, there is no introduction under the “product study” heading to let us know what aspects you are focused on, and does the heading “inputs/outputs” refer to the components that receives input from the user? Some explanation would be helpful.
• Energy is clearly an input to the product – it seems to be missing from the input/output list.
• We certainly understand that you chose to list only the printer components most relevant to your design goals; however, we had expected you not to skip any parts, but rather to describe certain components as assemblies if it turned out to be too labor intensive to list every component individually. For example, we did not find mention of gears in the components list except for the paper roller encoder gear – you should make sure that you do not miss any parts; however, if you wish to identify some subassemblies, such as the geartrain, as a single item in your list, that will be okay as long as you identify the set of components in the assembly. For the “subassembly analysis of the main gear”, to which item(s) on the parts list does this refer?
• From our experience, we believe that the encoder circuit probably uses a photointerrupter (LED and photodiode) rather than a laser – you might check this.
• There seems to be a long list of notes and images at the end of the report that repeat some of the information from the table above. Was this intended to function as an appendix? What conclusions did you draw from these notes?
• It seems that you have not described the function of the product, although you have described the function of the encoder subsystem. We had expected a description of the mechanical components of the entire printer. Please be sure to address this in your next report.
• We can tell you from our experience that environmental impact for this product will likely be dominated by the use phase – ink use and energy use. Does the printer use much energy when idling?
• It looks like you have identified three FMEA items – of course there are a great many more for the printer – how did you choose these three, and what are your recommendations?
• We appreciate your attempt to document the analysis of the main gear, but we found it difficult to understand without some context – a paragraph and maybe a picture would help.
• Also, please include a free body diagram with numerical analysis for one of the subsystems on the printer – for example the input/output speed and torque of one of the geartrains or an analysis of the forces on rollers during different phases. Please select the analysis that will be most appropriate for your needs in the next phase, but we would like to see some numerical analysis to determine if sizing of components is correct. You can talk with Prof. Michalek if you are unsure of the appropriateness of the analysis.

Additional Comments

It would be useful if your executive summary contained more of your researchers conclusions, rather than just being an introduction to your findings.

While your Design For lists some very useful and important ideas, it would be nice if you also listed a few ways in which their design could be improved.

Revision

We received your revised report 1, but we could not find responses to the comments we provided. It appears that you have addressed some of the issues in the report itself, but you did not provide a summary of responses on the discussion page, so it is difficult for us to assess. Please provide a summary. We also were unable to find the free body diagram and mechanical analysis requested.