Automatic card shuffler 2
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The results of this experiment also confirmed our thoughts about the product. While this user didn’t analyze the product from an engineering perspective, most of her observations echoed our thoughts in a less scientific sense. She did point out that some type of instruction card would have helped and she would be much more likely to continue using the product if it were quieter. This provides us a little bit of insight into the minds of the general consumer and what aspects we should focus on for future improvement. | The results of this experiment also confirmed our thoughts about the product. While this user didn’t analyze the product from an engineering perspective, most of her observations echoed our thoughts in a less scientific sense. She did point out that some type of instruction card would have helped and she would be much more likely to continue using the product if it were quieter. This provides us a little bit of insight into the minds of the general consumer and what aspects we should focus on for future improvement. | ||
+ | |||
+ | == Bill of Materials == | ||
+ | |||
+ | {| class="wikitable" border="1" | ||
+ | |- | ||
+ | ! Part No. !! Part !! Qty. !! Wt. (oz) !! Material !! Function !! Manuf. Proc. !! Picture | ||
+ | |- | ||
+ | !Plastic Components | ||
+ | |- | ||
+ | ! 1 | ||
+ | |Cover plate support||1||0.025||Plastic||Holds together cover plate sub-assembly||Injection molding||[[IMAGE:Cover_Plate_Support.jpg|300PX]] | ||
+ | |- | ||
+ | ! 2 | ||
+ | |Cover plate||1||0.8||Plastic||Stops cards from flying up out of device||Injection molding||[[IMAGE:Cover_Plate.jpg|300PX]] | ||
+ | |- | ||
+ | !3 | ||
+ | |Card receptacle sleeve||1||0.7||Plastic||Catches shuffled cards and facilitates their removal||Injection molding||[[IMAGE:Card_Recepticle_Sleeve.jpg`|300PX]] | ||
+ | |- | ||
+ | !4 | ||
+ | |Battery flap||2||>0.1||Plastic||Covers batteries||Injection molding||[[IMAGE:Battery_Flap.JPG.JPG|300PX]] | ||
+ | |- | ||
+ | !5 | ||
+ | ||Main body||1||6.2|| Plastic||Hold device together/give product shape||Injection molding||[[IMAGE:Main_Casing.JPG|300PX]] | ||
+ | |- | ||
+ | !6 | ||
+ | |Motor holder plate||2||0.1||Plastic||Holds motor to gear sub-assembly||Injection molding||[[Motor_Holder_Plate.jpg|300PX]] | ||
+ | |- | ||
+ | !7 | ||
+ | |Button||1||>0.1||Plastic||Turns shuffler on||Injection molding||[[IMAGE:Operating_Button.JPG.JPG|300PX]] | ||
+ | |- | ||
+ | !8 | ||
+ | |Plastic washer (button)||1||>0.1||Plastic||Separate metal screw from contact switches in button sub-assembly||Injection molding||[[IMAGE:Plastic_Washer.JPG.JPG|300PX]] | ||
+ | |- | ||
+ | !9 | ||
+ | |Gear 1||2||>0.1||Plastic||Gear down motor to slow it down||Injection molding||[[IMAGE: Shuffler_Gear_1.JPG|300PX]] | ||
+ | |- | ||
+ | !10 | ||
+ | |Gear 2||2||>0.1||Plastic||Continues card motion through the shuffling slot||Injection molding||[[IMAGE: Shuffler_Gear_2.JPG|300PX]] | ||
+ | |- | ||
+ | !11 | ||
+ | |Gear 3||2||>0.1||Plastic||Initial impact on card to start motion||Injection molding||[[IMAGE: Shuffler_Gear_3.JPG|300PX]] | ||
+ | |- | ||
+ | !12 | ||
+ | |Gear 4||2||>0.1||Plastic||Gear down motor to slow it down||Injection molding||[[IMAGE: Shuffler_Gear_4.JPG|300PX]] | ||
+ | |- | ||
+ | !13 | ||
+ | |Gear 5||2||>0.1||Plastic||Gear down motor to slow it down||Injection molding||[[IMAGE:Shuffler_Gear_5.JPG|300PX]] | ||
+ | |- | ||
+ | !14 | ||
+ | |Gear box||2||>0.1||Plastic||Hold gears in place and to motor||Injection molding||[[IMAGE:Gear_Box.JPG.JPG|300PX]] | ||
+ | |- | ||
+ | !15 | ||
+ | |Bottom plate||1||2.7||Plastic||Provides surface for gears and motors to attach to, provides space for batteries and attaches to main body to create shape of device||Injection molding||[[IMAGE:Bottom_Plate.JPG.JPG|300PX]] | ||
+ | |- | ||
+ | !Electrical components | ||
+ | |- | ||
+ | !16 | ||
+ | |Contact switch||2||>0.1||Copper||Complete electrical circuit when button is pressed to provide power to the motor||Cut and stamped|| [[IMAGE:Contact_Switch.JPG.JPG|300PX]] | ||
+ | |- | ||
+ | !17 | ||
+ | |Purple wire (9.2 in)||1||>0.1||Copper, Plastic insulation||Feedback link between two motors||Purchased|| [[IMAGE:WHEELS.JPG|300PX]] | ||
+ | |- | ||
+ | !18 | ||
+ | |Red wire (4.5 in)||2||>0.1|| Copper, Plastic insulation ||Connect contact switches to motors|| Purchased || [[IMAGE:WHEELS.JPG|300PX]] | ||
+ | |- | ||
+ | !19 | ||
+ | |White wire (8 in)||1||>0.1|| Copper, Plastic insulation ||||Feedback link between two motors || Purchased || [[IMAGE:WHEELS.JPG|300PX]] | ||
+ | |- | ||
+ | !20 | ||
+ | |Black wire (1.5 in)||1||>0.1|| Copper, Plastic insulation ||Ground wire|| Purchased || [[IMAGE:WHEELS.JPG|300PX]] | ||
+ | |- | ||
+ | !21 | ||
+ | |Black wire (6.5 in)||1||>0.1|| Copper, Plastic insulation ||Ground wire|| Purchased || [[IMAGE:WHEELS.JPG|300PX]] | ||
+ | |- | ||
+ | !22 | ||
+ | |Negative battery terminal||4||>0.1||Aluminum||Connects negative side of battery to circuit to provide power to the motors||Stamped, spring drawn out|| [[IMAGE:Neg_Battery_Terminal.JPG.JPG|300PX]] | ||
+ | |- | ||
+ | !23 | ||
+ | |Positive battery terminal||4||>0.1||Aluminum||Connects positive side of battery to circuit to provide power to the motors||Stamped|| [[IMAGE:Pos_Battery_Terminal.JPG.JPG|300PX]] | ||
+ | |- | ||
+ | !24 | ||
+ | |Standard motor||2||1.0||Purchased||Turn gears in order to force motion of cards||Purchased|| [[IMAGE:Card_Shuffler_Motor.JPG.JPG|300PX]] | ||
+ | |- | ||
+ | !Fasteners | ||
+ | |- | ||
+ | !25 | ||
+ | |Visible flathead screw||4||>0.1||Steel alloy||Attaches cover plate sub-assembly to body of device||Purchased||[[IMAGE:Visible_Screws.JPG|300PX]] | ||
+ | |- | ||
+ | !26 | ||
+ | |Small screw in cover plate sub-assembly||2||>0.1||Steel alloy||Holds together cover plate sub-assembly||Purchased||[[IMAGE:Small_Screw_Cover_Plate.JPG|300PX]] | ||
+ | |- | ||
+ | !27 | ||
+ | |Washer for small screw in cover plate sub-assembly||2||>0.1||Steel alloy||Locks cover plate sub-assembly together||Purchased||[[IMAGE:Cover_Plate_Washers.jpg|300PX]] | ||
+ | |- | ||
+ | !28 | ||
+ | |Battery area screw 1||4||>0.1||Steel alloy||Holds motor plate to body of device||Purchased||[[IMAGE:Battery_Area_Screw1.JPG|300PX]] | ||
+ | |- | ||
+ | !29 | ||
+ | |Battery area screw 2||4||>0.1||Steel alloy||Holds together gear box sub-assembly||Purchased||[[IMAGE:Battery_Area_Screw2.JPG|300PX]] | ||
+ | |- | ||
+ | !30 | ||
+ | |Button screw||1||>0.1||Steel alloy||Holds together button sub-assembly and allows the pressing of button to complete electrical circuit||Purchased||[[IMAGE:Button_Screw.JPG|300PX]] | ||
+ | |- | ||
+ | !Miscellaneous Metal Components | ||
+ | |- | ||
+ | !31 | ||
+ | |Hinged metal piece in cover plate sub-assembly||1||0.15||Aluminum||Prevents more than a few cards from entering center slot at once||Stamping, Bending|| [[IMAGE:Top_Sub-assembly_Hinge.JPG|300PX]] | ||
+ | |- | ||
+ | !32 | ||
+ | |Shaft in gear box (0.9 in)||2||>0.1||Steel alloy||Goes through center of gears and through gear box to hold gears to the gear box||Drawn out, Cut|| [[IMAGE:Smooth_Shaft.JPG|300PX]] | ||
+ | |- | ||
+ | !33 | ||
+ | |Grooved shaft in gear box (0.9 in)||4||>0.1||Steel Alloy|| Goes through center of gears and through gear box to hold gears to the gear box || Drawn out, Cut || [[IMAGE:Grooved_Shaft.JPG|300PX]] | ||
+ | |- | ||
+ | |||
+ | |||
== Design for Manufacturing and Assembly == | == Design for Manufacturing and Assembly == |
Revision as of 16:33, 5 February 2011
Contents |
Report 1: Competitor Product Analysis - Executive Summary
Major Stakeholders and Needs
There are four main stakeholders for this product: Families/Individuals, Casinos, Retail Stores, and Shipping Companies. Each of these stakeholders has different needs, although most of these needs align nicely with each other. The resulting needs are summarized below.
Families/Individuals
Families and individuals are the main users for this product. As such, these users have the most and most well-defined needs in regard to a card shuffler. Their needs are as follows:
- Low cost
- Appealing aesthetics
- Small, lightweight, and portable
- Able to be operated by adults and children age 8+
- Should not jam easily
- Shuffle at least 2 decks of cards
- Fast, should be faster than shuffling by hand
- Minimal/no assembly required
- Child-proof (no sharp edges, little to no risk of fingers getting pinched)
- Uses standard batteries
- Easy to store
- Quiet (so as to not disturb conversation)
- Accident-proof/Waterproof
- Cordless/battery-operated
- Easy to clean
- Sit flat/balance on table
Casinos
Casinos make up the second set of stakeholders in this product. While it is more likely that these establishments would purchase higher end card shufflers, it is possible that they would use our product as a low cost alternative. Their needs are as follows:
- Very Reliable (cards don’t jam)
- Appealing Aesthetics
- Shuffle at least 2 (potentially more) decks of cards
- Very Fast
- Small/doesn’t take up a lot of space
- Cordless/battery-operated (so that patrons don’t trip on cord)
- Sit flat/balance on table
- Easy to clean
Retail Stores
Retail stores are the ones who will be stocking our product and serve as the middle-man between production and the end user. As such they have a special set of needs in regards to our product, which are as follows:
- Small and lightweight
- Easy to store and stack
- Appealing packaging
- Reliable/high quality
- Low wholesale cost
Shipping Companies
Shipping companies make up the final main stakeholder in our analysis. Their needs are similar to the retail store, but they also have several differences. Their needs are as follows:
- Small/compact packaging
- Easy to stack/fit in standard boxes without wasted space
- Lightweight
Product Operation
Upon being removed from its packaging, the competitor card shuffler must be equipped with 4 C batteries (not included). Two batteries are placed in each side of the base by opening two plastic tabs that lift two flaps to reveal the respective battery locations (see image to the right). It is interesting to note that the springs for each negative terminal twist and bend, thus providing only marginal contact between them and the batteries.
After inserting the batteries and closing the flaps, the entire shuffler can then be equipped with decks of playing cards on each side of the clear plastic top. Note that according to the competitor's description, up to 2 decks can be placed on either side, though for the operation illustrated in the pictures, only one deck was placed on either side. The image to the left illustrates this first step of operation. Also, the loose clear plastic tray should be situated snugly within the alcove prior to operation of the shuffler.
To begin shuffling the decks of cards, a plate labeled "Press Down to Operate" is pushed. The plate must be held down continuously until both decks are completely processed through the shuffler. Cards are shuffled by being shot forward via a circulating wedge that is driven by the internal gears and motor. The wedge regularly breaks the surface of the deck-holding area, thrusting the card in contact with it towards a narrow crevice underneath the clear plastic top. Cards then fall onto the plastic tray. At the end of this report, a link to a video of the card shuffler in use can be seen.
Since the wedges on either side of the card collection cache move out of sync, the cards from either deck enter at alternating times. Sporadically during any given run, some cards from either side get caught along the side walls of the collection cache and do not fall onto the other cards accumulating on the plastic tray.
Once all the cards have been thrown into the cache, removal is performed by clasping the edges of the plastic tray and sliding it out. Care has to be taken on the user's part to ensure cards in a large stack (i.e. when more than 2 decks are shuffled) are not accidentally shaken off. Once fully removed from the shuffler cache, the cards themselves can be removed from the tray and used for play. The plastic tray is then re-inserted in the cache.
Post-operation maintenance and storage is very simple. The biggest detriment to the shuffler's useful life-span is the accumulation of dust over not just the entire surface, but upon the exposed gear assemblies. Over an extended period of time, dust and dirt accumulation on the gears can lead to destruction of the teeth (exacerbated during operation while not clean), which will wear down or loosen due to the minuscule (but growing) obstructions. Therefore, some cleaning must be done regularly if the shuffler is used often (once a week, for example) and kept out in the open. A dry cloth or rag will suffice in order to remove the majority of the superficial dust. However, for long-term survival, storing the shuffler in the box that it came packaged in is a viable and cost-effective option for the user. Note that while these care and maintenance suggestions have been discussed, they are no where to be mentioned in any documentation that came with the shuffler, no doubt signaling the manufacturer's intent to merely create and sell a "bare bones" model that is intended to be thrown away upon the first failure not attributable to dead batteries.
User Studies
Engineer's Analysis
Before we tested this product with a random user to see how they would use the shuffler, we conducted our own user study to see how we thought that it performed from an engineering standpoint. Our results can be seen below.
Good Points:
- Cheap (~$16)
- Small size
- Portable
- Easy to store
- Easy to clean
Areas for Improvement:
- Loud (could scare pets, children, unsettling to adults)
- Uses C batteries (not conventional AA or AAA), does not indicate on box what type of batteries are required, needs 4 batteries total
- Cards occasionally get stuck/jammed with 2 decks of cards (because shuffler takes too many cards at once from one side)
- Cards almost always get stuck with 3+ decks of cards (advertised as able to handle 4 decks)
- Have to hold button down entire time, cannot just press once
- Dangerous for finger pinching
- No directions or safety guidelines provided
- Battery springs deform very easily
- Does not shuffle particularly well, cards “clump”
These findings indicate much of what we suspected from the start, which is that you get what you pay for. This card shuffler is designed to be a cheap alternative to shuffling cards by hand, where quality is not always the highest priority. The main issue that we found with this product pertains to the main function, which is its ability to actually shuffle cards. For one or two decks, the product performs relatively well, with both sides finishing at almost the same time. Once additional decks are added, the performance drops drastically, with the product frequently jamming or having one side finish several seconds before the other. The main issues involve the fact that the shuffler is loud and the button to shuffle the cards needs to be held down the entire time the cards are being shuffled. While these issues do not affect the usability of the product, they are definite areas for improvement to improve the general product experience for the user.
General Consumer's Analysis
To get an outside opinion on the product and its usability, we got a volunteer to use the product and tell us their general opinions and impressions about the product. No instructions were given to the volunteer about how to use the product so that we could observe the thought process of how users approach such a product. This would also simulate the experience of actually buying the product and using it for the first time since no instructions were included with the product. The volunteers thoughts are summarized below:
- Thought product was cool (hadn’t seen before)
- Did not find button immediately
- Hesitated when pushing button which caused a jam
- Noise shocked her
The results of this experiment also confirmed our thoughts about the product. While this user didn’t analyze the product from an engineering perspective, most of her observations echoed our thoughts in a less scientific sense. She did point out that some type of instruction card would have helped and she would be much more likely to continue using the product if it were quieter. This provides us a little bit of insight into the minds of the general consumer and what aspects we should focus on for future improvement.
Bill of Materials
Part No. | Part | Qty. | Wt. (oz) | Material | Function | Manuf. Proc. | Picture | |||
---|---|---|---|---|---|---|---|---|---|---|
Plastic Components | ||||||||||
1 | Cover plate support | 1 | 0.025 | Plastic | Holds together cover plate sub-assembly | Injection molding | ||||
2 | Cover plate | 1 | 0.8 | Plastic | Stops cards from flying up out of device | Injection molding | ||||
3 | Card receptacle sleeve | 1 | 0.7 | Plastic | Catches shuffled cards and facilitates their removal | Injection molding | Image:Card Recepticle Sleeve.jpg` | |||
4 | Battery flap | 2 | >0.1 | Plastic | Covers batteries | Injection molding | ||||
5 | Main body | 1 | 6.2 | Plastic | Hold device together/give product shape | Injection molding | ||||
6 | Motor holder plate | 2 | 0.1 | Plastic | Holds motor to gear sub-assembly | Injection molding | 300PX | |||
7 | Button | 1 | >0.1 | Plastic | Turns shuffler on | Injection molding | ||||
8 | Plastic washer (button) | 1 | >0.1 | Plastic | Separate metal screw from contact switches in button sub-assembly | Injection molding | ||||
9 | Gear 1 | 2 | >0.1 | Plastic | Gear down motor to slow it down | Injection molding | ||||
10 | Gear 2 | 2 | >0.1 | Plastic | Continues card motion through the shuffling slot | Injection molding | ||||
11 | Gear 3 | 2 | >0.1 | Plastic | Initial impact on card to start motion | Injection molding | ||||
12 | Gear 4 | 2 | >0.1 | Plastic | Gear down motor to slow it down | Injection molding | ||||
13 | Gear 5 | 2 | >0.1 | Plastic | Gear down motor to slow it down | Injection molding | ||||
14 | Gear box | 2 | >0.1 | Plastic | Hold gears in place and to motor | Injection molding | ||||
15 | Bottom plate | 1 | 2.7 | Plastic | Provides surface for gears and motors to attach to, provides space for batteries and attaches to main body to create shape of device | Injection molding | Image:Bottom Plate.JPG.JPG | |||
Electrical components | ||||||||||
16 | Contact switch | 2 | >0.1 | Copper | Complete electrical circuit when button is pressed to provide power to the motor | Cut and stamped | ||||
17 | Purple wire (9.2 in) | 1 | >0.1 | Copper, Plastic insulation | Feedback link between two motors | Purchased | Image:WHEELS.JPG | |||
18 | Red wire (4.5 in) | 2 | >0.1 | Copper, Plastic insulation | Connect contact switches to motors | Purchased | Image:WHEELS.JPG | |||
19 | White wire (8 in) | 1 | >0.1 | Copper, Plastic insulation | Feedback link between two motors | Purchased | Image:WHEELS.JPG | |||
20 | Black wire (1.5 in) | 1 | >0.1 | Copper, Plastic insulation | Ground wire | Purchased | Image:WHEELS.JPG | |||
21 | Black wire (6.5 in) | 1 | >0.1 | Copper, Plastic insulation | Ground wire | Purchased | Image:WHEELS.JPG | |||
22 | Negative battery terminal | 4 | >0.1 | Aluminum | Connects negative side of battery to circuit to provide power to the motors | Stamped, spring drawn out | ||||
23 | Positive battery terminal | 4 | >0.1 | Aluminum | Connects positive side of battery to circuit to provide power to the motors | Stamped | ||||
24 | Standard motor | 2 | 1.0 | Purchased | Turn gears in order to force motion of cards | Purchased | ||||
Fasteners | ||||||||||
25 | Visible flathead screw | 4 | >0.1 | Steel alloy | Attaches cover plate sub-assembly to body of device | Purchased | ||||
26 | Small screw in cover plate sub-assembly | 2 | >0.1 | Steel alloy | Holds together cover plate sub-assembly | Purchased | ||||
27 | Washer for small screw in cover plate sub-assembly | 2 | >0.1 | Steel alloy | Locks cover plate sub-assembly together | Purchased | ||||
28 | Battery area screw 1 | 4 | >0.1 | Steel alloy | Holds motor plate to body of device | Purchased | ||||
29 | Battery area screw 2 | 4 | >0.1 | Steel alloy | Holds together gear box sub-assembly | Purchased | ||||
30 | Button screw | 1 | >0.1 | Steel alloy | Holds together button sub-assembly and allows the pressing of button to complete electrical circuit | Purchased | ||||
Miscellaneous Metal Components | ||||||||||
31 | Hinged metal piece in cover plate sub-assembly | 1 | 0.15 | Aluminum | Prevents more than a few cards from entering center slot at once | Stamping, Bending | ||||
32 | Shaft in gear box (0.9 in) | 2 | >0.1 | Steel alloy | Goes through center of gears and through gear box to hold gears to the gear box | Drawn out, Cut | ||||
33 | Grooved shaft in gear box (0.9 in) | 4 | >0.1 | Steel Alloy | Goes through center of gears and through gear box to hold gears to the gear box | Drawn out, Cut |
Item and Function | Failure mode | Effects of Failure | S | Causes of Failure | O | Design Controls | D | RPN | Recommended Actions | |
---|---|---|---|---|---|---|---|---|---|---|
Wire – makes electrical connections | Wires come unattached | The system won’t operate | 5 | Dropping, wearing out or repeated use | 2 | The motor won’t turn on while testing | 2 | 30 | Have more spaces between contacts, make stronger connections, longer wires | |
Gears – drive cards through shuffler | The gears can be loosely assembled or misaligned; the lubricant on the gear could dry out | Whole assembly stops moving, it causes more noise or can break | 7 | Poor manufacturing – inexact teeth, overuse | 3 | can see the irregular motion of the cards; they do not move in the right direction | 1 | 21 | Requires higher precision manufacturing | |
Plastic – casing holding the parts together | Cracks, pieces breaking off | All parts will come apart, therefore it will not shuffle the cards correctly | 4 | high impact caused by dropping the product | 4 | cracking sound of plastic | 1 | 16 | use better quality plastic; provide some kind of rubber covering at the corners | |
Motor – runs the gears | Motors burn out or stop working | The gear system will stop working | 5 | Usually occurs due to overuse | 5 | Object stops working entirely when tested | 1 | 25 | The motor has to be replaced or requires service. | |
Plastic Card catcher | It is not attached properly therefore can be easily lost | Easy to lose and harder to remove cards | 3 | Lost in transportation | 5 | If you don’t see it then you know its lost | 1 | 25 | Have some kind of groove to slide it in instead of it just sitting in the space. |
FMEA Conclusion
The most significant failure of our products is that of the gear system which could result due to improper manufacturing. Most of the other modes of failure are due to improper use or over use. We will address these failures in our new part based on the recommended solutions listed in the table above.
Team Member Roles
- Alexander Harber - Team Leader
- Alana Yoel - Safety Lead
- Paul Wagner - Manufacturing Lead
- Tanvi Bubna - Environmental Lead
Roles in the team formed more so than they were selected. With each exercise in class regarding DFMA, FMEA, and DFE, a different person naturally took to over-seeing its completion not just in class, but during our own reunions for the sake of writing this report. A couple of us had worked together before on previous projects, so there was a spark of familiarity that promoted thorough collaboration right from the start.