From DDL Wiki

First Report

We received your report on the automatic card shuffler and were confused. The report appears to be incomplete, and it fails to address the items agreed upon for deliverables. You were highly recommended by Professor Michalek as being a confident team with the necessary skills for the project, so we cannot understand why you have submitted such a poor and incomplete document to us – is there some mistake? It’s clear that you have begun to do some work on the project, since we see an initial BOM and some bulleted lists, but the document fails to adequately address any of the items we asked for, and it doesn’t even look like a report at all, but rather just some notes.

We also received a letter from you via the Blackboard site that provides somewhat of an overview, but you must understand that your documentation is far below our expectations. We will plan to meet with you this Wednesday to discuss the situation and determine what steps should be taken next. We expect that your next report will deliver the missing information that was supposed to appear in this report and do a competent job addressing the requirements for the next deadline.

---

We received your revised report on the automatic card shuffler, and it looks like you have done some interesting analysis and came up with a few good ideas for minor improvements of the design. We will be looking forward to your next report to see if you come up with more substantial design ideas or are able to do more in-depth analysis of your proposed improvements if they turn out to be straightforward. 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. [We have revised our executive summary to includes our conclusions]
• You mention an important point about randomness - if card shuffler shuffles the cards too consistently, then a card-counter might be able to predict the outcome of the deck. The need for a certain amount of randomness might be very important in these situations. [Addressed in section 6 - Market Research and Observations and in the Card Shuffler Improvement Ideas page]
• You mention “human error” several times in the report – what do you mean? To what kind of “error” are you referring. [Addressed in executive summary]
• You mention that the shuffler will save time; however, the dealer must still cut cards, set them, wait for the shuffler to operate, and then remove the deck from the tray. Have you observed that it actually saves time in practice? [Section 6 - Market Research and Observations]
• You bring up an important point about the need to avoid damaging cards (this should be a customer need). The automatic shuffler reduces bending, but it also increases side impact as cards bang against the tray. Is the effect of side impact negligible, or will this wear cards out over time? [Section 6 - Market Research and Observations]
• Removable tray – do cards have to be turned over to get them out, revealing bottom card? [Section 2.4 Use and Operation]
• It is difficult to understand the description of how the product works without a labeled picture of the assembly. Please include one in your revised report. [Section 2 How the System Fucntions]
• The parts list appears to be very incomplete. For example, the cover, base, and card tray appear to be missing from the list, and you did not respond to our request to identify likely manufacturing processes for each component. The “clear top cover” also appears to be an assembly.
• We’re curious about your analysis that the motor was probably the only component that the manufacturer did not produce themselves. Gears, wires, and fasteners are typically purchase components.
• Interesting DFE opportunity. Do you think there is a good solution where the user can actuate the shuffling process without an electric motor (for example, by pressing down on a lever or turning a crank?) [covered in Section 4.1 Design for Environment]
• Interesting items in your FMEA table – what are your recommendations? Also, what happens if the cards are shuffled without the tray in place? [Section 5 Failure Mode and Effects Analysis]

Revision

We received your response to our comments on the first report, and we are generally satisfied with the response; however, the report still seems to contain incomplete text such as “post conclusions and recommendations from the fmea table here”. For the final report, please split your reports into two pages – the first will be “automatic card shuffler”, and the second will be “automatic card shuffler redesign”. We also realize that we failed to ask you for a mechanical analysis of the card shuffler, but we would like you to calculate torque and speed reduction from the motor to the card and find out how much force and speed is applied to the card (using normal forces with a full deck and with a single card to capture the range). This information should be helpful both in examining the current product and in your redesign.

Report 2

We received your second report (which you integrated into the revision of your first report), and you have identified some important opportunities. It appears that there were some incomplete sections in the report. We found text such as “add more research topics here”. We also did not find your VOA. You have made some good observations, including the importance of random card ordering, the time taken to use the shuffler, observations about the experience of using the shuffler (noise, fun, etc), and the observation that the shuffler makes cards last longer by avoiding bending. This may also be able to help prevent cheating (http://www.pokerology.com/articles/cardcheating.htm, http://www.cardcheaters.com/). Your list of improvement ideas all make sense, and many would be easy to implement. FYI, the choice of wire gauge is for cost reduction.

You have interesting initial ideas for design concepts, although some refinement is needed. The ramp idea is a nice idea – very simple. This would require testing to avoid cards becoming jammed - If cards arrive faster than they can fall into ramp slot, what would happen? The automatic card cutting concept is great – consumers and players would like it – but we can’t quite see how your sketch would accomplish both cutting and shuffling. A more detailed sketch needed before we can assess feasibility. This design would require testing to ensure robustness and avoid jamming or other failures. The digital readout is an interesting idea. Programming game rules would be a better project for a programmer, but card counting is something you could implement. Have you identified a real need for a card counting feature? Finally, the elongated card slot idea is interesting. Our first concern is increased potential for jamming – suppose two cards fall one after the other on the ramp below – these cards may butt up against one another rather than one sliding on top of the other. Secondly, it seems to us that the majority of the deck would slide to the bottom of the rack and be fed by the last wheel. The concept does not appear very robust. The increased footprint is also a significant concern. The primary advantage seems to be novelty and fun of the experience using it (like a Rube Goldberg machine). This is a fun direction to go, but we don’t think the current sketch is there yet.

We think you have identified some very important areas, but your design concepts require another iteration and quick movement into detailed design for analysis and testing. Our suggestion is to follow one of two paths:

• 1) Improve existing design: Integrate the ideas of concept 1,2 and 4 into a single device that cuts cards, increases randomness of shuffle, and outputs cards via ramp to improve retrieval. Also integrate noise reducing options that were mentioned but not shown in the concepts. We suggest that you consider simpler and more reliable ways to improve randomness of shuffling, including varying the voltage to each motor with a periodic function or adding a mechanical approach to randomizing motor speed. The card cutting concept also must be more fully flushed out. This option would require detailed analysis of shuffling patterns, including dynamics of the motors, as well as significant testing.
• 2) New shuffler/dealer concept: Pursue concept 3, but do not focus on the digital readout interface design (which we can hire electrical engineers to do). Instead, implement a card counter (probably using photointerrupters) and brainstorm concepts for the device to automatically deal cards (would require new motors and controls). We would then take your dealing concept to an electrical engineering team who could program the device to deal differently for different games. This option would require a fast iteration of brainstorming and immediate movement into detailed design, and it would require some research on your part for electromechanical components and basic circuits.

We look forward to seeing your prototypes in the design review.