Paper towel dispenser

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(→FMEA Analysis)
(→FMEA Analysis)
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| 01 || Front Housing || Protects device from exterior ||Fractures||  
+
| 01 || Front Housing || Protects device from exterior ||Fractures, Warped||  
*Exposure of internal components  
*Exposure of internal components  
*Possible injury to customer
*Possible injury to customer
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||6||
||6||
* Improper handling
* Improper handling
-
* Improper assembling
 
* Improper manufacturing
* Improper manufacturing
* Incorrect design
* Incorrect design
||3||
||3||
* Material selection
* Material selection
-
* Injection mold design
+
* Mold design
||2||36||  
||2||36||  
-
* Select a reliable material  
+
* Select a flexible and elastic material  
||Assembly and Manufacturing
||Assembly and Manufacturing
|-  
|-  
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*Possible injury to customer
*Possible injury to customer
||7||
||7||
-
* Improper usage
+
* Improper handling
* Poor upkeep
* Poor upkeep
||6||
||6||
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*Malfunctioning of mechanical spindle
*Malfunctioning of mechanical spindle
||3||
||3||
-
* Improper usage
 
* Fatigue
* Fatigue
||2||
||2||
* Material selection
* Material selection
-
* Improperly aligned spring
+
* Improper assemblying
||5|| 30||
||5|| 30||
* Select a stiffer material
* Select a stiffer material
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*Malfunctioning of mechanical spindle
*Malfunctioning of mechanical spindle
||3||
||3||
-
* Improper usage
+
* Improper handling
* Fatigue
* Fatigue
||2||
||2||
* Material selection
* Material selection
-
* Improperly aligned spring
+
* Improper assemblying
||4 || 24||
||4 || 24||
* Select a stiffer material
* Select a stiffer material
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* Unable to confine rotation direction of spindle
* Unable to confine rotation direction of spindle
||3||
||3||
-
* Improper usage
+
* Improper handling
* Fatigue
* Fatigue
||2||
||2||
* Material selection
* Material selection
 +
* Improper assemblying
||4 || 24||
||4 || 24||
* Select a stiffer material
* Select a stiffer material
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*Malfunctioning of mechanical spindle
*Malfunctioning of mechanical spindle
||5||  
||5||  
-
*Improper usage
+
*Improper handling
-
*Incorrect Design/Manufacturing
+
*Improper manufacturing
||2||
||2||
*Material selection
*Material selection
||2||20||
||2||20||
*Select a stiffer material
*Select a stiffer material
-
|| Assembly and Reliablity
+
|| Manufacturing and Reliablity  
|-  
|-  
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*Malfunctioning of mechanical spindle
*Malfunctioning of mechanical spindle
||5||  
||5||  
-
*Improper usage
+
*Improper manufacturing
-
*Incorrect Design/Manufacturing
+
*Improper assemblying
||2||
||2||
*Material selection
*Material selection
 +
*Mold design
||3||30||
||3||30||
*Select a stiffer material
*Select a stiffer material
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*Unable to adjust spring to a desired angle
*Unable to adjust spring to a desired angle
||3||  
||3||  
-
*Improper usage
+
*Improper handling
-
*Incorrect Design/Manufacturing
+
*Improper manufacturing
||2||
||2||
*Material selection
*Material selection
||2||12||
||2||12||
None
None
-
|| Assembly and Reliablity
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|| Manufacturing
|-  
|-  
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* User dissatisfaction
* User dissatisfaction
||4||
||4||
-
*Improper usage
+
*Improper handling
-
*Incorrect Design/Manufacturing
+
*Improper manufacturing
-
||2||
+
||3||
-
* Packaging
+
* Material selection
-
||1||8||
+
||1||12||
-
* None
+
* Select a stiffer material
-
||Assembly
+
|| Manufacturing
|-  
|-  
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* User dissatisfaction
* User dissatisfaction
||2||
||2||
-
*Improper usage
+
*Improper assemblying
-
*Incorrect Design/Manufacturing
+
*Improper manufacturing
||2||
||2||
*  
*  

Revision as of 00:47, 20 September 2009

Contents

Executive Summary

Stakeholders

There are six major stakeholders with regards to the paper towel dispenser: Manufacturer, retailer, customer, user, society. The main needs for the manufacturer are to reduce cost and create a reliable product. For the retailer, it is being able to sell a quality product. For the customer, it is making sure it is an affordable and reliable machine. For the customer, cleanliness and ease of use are paramount. For the maintenance worker, ease of opening and replacing the paper towel are important. Society plays a role with regards to how the use of paper towel affects the ecosystem and earth in general. Listed below are the stakeholders and their respective needs.


Paper Towel Manufacturer

  • Material cost
  • Manufacturing cost
  • Assembly
  • Transporting
  • Standardize/minimize parts


Retailer

  • Cost
  • Storage
  • Reliability
  • Usability
  • Transporting


Customer

  • Cost
  • Mounting
  • Ease of use
  • Reliability
  • Aesthetics
  • Safety


User

  • Ease of use / ergonomics
  • Speed of operation
  • Aesthetics
  • Cleanliness
  • Safety


Maintenance Worker

  • Ease of towel replacement
  • Safety


Society

  • Environment

Usability Study

Assembly Pictures

How it Works

Mechanical Analysis

Parts List

Part No. Name Function QTY Weight Material Manufacturing Process Image
01 Front Housing Protects device from exterior 1 935g Plastic Injection Molding
02 Front Housing Clip Holds housings together 1 13g Steel Bending, Punching
03 Front Housing Tab Secures housing clip 1 <1g Plastic Injection Molding
04 Rear Housing Holds mechanical components 1 986g Plastic Injection Molding
05 Paper Towel Holding Arm Holds paper towel roll 2 40g each Plastic Injection Molding
06 Phillips Head Screw (1/8 x 1/4 long) Secures device to rear housing 1 1g Steel Machined
07 Wall Mounting Screw (1/8 x 1.25 long) Secures housing to wall 4 3.5g each Steel Machined
08 Screw Anchor Holds screw in wall 4 ~0.25g Plastic Injection molding
09 Paper Guide Tube Guides paper towel to cutting cylinder 1 55g Plastic Injection molding [[Image:| 100x100px]]
10 Spring (uneven hooks) Holds 09 in place 2 2g each Metal Extrusion
11 Spring (even hooks) Holds lever to spindle housing 2 1.5g each Metal Extrusion
12 Screw (3/32 x 5/8 long) holds turning wheel and lever to spindle housing 2 ~1g each Metal Extrusion
13 Red Screw Cap Hides screw in turning wheel 1 <1g Plastic Injection molding
14 Locking Spring Ensures correct wheel spin direction 1 4g Steel Extrusion
15 Red Turning Wheel Turns main spindle 1 30g Plastic Injection molding
16 Guide clips for 09 Guides paper on 09 2 2.5g each Plastic Injection molding [[Image:| 100x100px]]
17 Screw (3/32 x 3/8 long) Holds lever assembly together and spindle housing 2 <1g each Metal Machined
18 Lever Arm Connects spring to spindle 1 1g Plastic Injection molding
19 Spring Connector Connects two springs to lever arm 1 <1g Plastic Injection molding
20 Rounded Spring Guide Angles spring to desired measurement 1 <1g Plastic Injection molding
21 Thin Paper Guide Guides paper out of device 1 24g Plastic Injection molding
22 Front Spindle Housing Final housing before paper leaves device 1 132g Plastic Injection molding
23 Spindle Housing Back Back of spindle housing 1 162g Plastic Injection molding
24 Spindle Housing (L) Left of spindle housing 1 105g Plastic Injection molding
25 Spindle Housing (R) Right of spindle housing 1 105g Plastic Injection molding
26 White Spindle Guide Holds spindle in line 3 2.3g each Plastic Injection molding
27 Screw (3/32 x 3/8 long) Connects spindle halves 2 <1g Metal Machined
28 Square nut For use with 27 2 <1g Steel Cast and drilled
29 White Teeth Guide/Arm Guides cutting teeth in spindle 2 3g each Plastic Injection molding
30 Cutting Teeth Cuts paper towel 1 75g Steel Cast, punched and bent
31 Spindle Top Half Holds cutting tool 1 125g Plastic Injection molding
32 Spindle Bottom Half Holds cutting tool 1 135g Plastic Injection molding
33 Metal Key Helps open housing 1 5g Steel Punched


DFMA Analysis


Design For Manufacture

Design For Assembly

FMEA Analysis



Part No. Name Function Failure Mode Effects of Failure S Causes of Failure O Design Controls D RPN Recommended Actions Responsibility
01 Front Housing Protects device from exterior Fractures, Warped
  • Exposure of internal components
  • Possible injury to customer
7
  • Improper handling
  • Improper manufacturing
4
  • Material selection
2 56
  • Drop test
Reliability


02 Front Housing Clip Holds housings togetherBends
  • Housings fell apart
4
  • Improper handling
  • Improper assembling
2
  • Material Selection
  • Packaging
648
  • Select a stiffer material
Assembly and Reliablity


03 Front Housing Tab Secures housing clip Strips
  • Housing clip exposed
2
  • Improper assembling
  • Improper manufacturing
2
  • Material selection
  • Mold design
832
  • None
Assembly


04 Rear Housing Holds mechanical components Fractures
  • Unable to hold mechanical components
7
  • Improper handling
  • Improper manufacturing
4
  • Material Selection
9 252
  • Drop test
  • Select a stiffer material
Reliability
05 Paper Towel Holding Arm Holds paper towel roll Bends
  • Unable to hold paper towel roll due to misaligned components
6
  • Improper handling
  • Improper manufacturing
  • Incorrect design
3
  • Material selection
  • Mold design
236
  • Select a flexible and elastic material
Assembly and Manufacturing
08 Screw Anchor Holds screw in wall Fractures
  • Unable to hold mechanical components
  • Possible injury to customer
7
  • Improper handling
  • Poor upkeep
6
  • Material selection
8336
  • Select a reliable material
Reliablity
09 Paper Guide Tube Guides paper towel to cutting cylinder Failed
10 Spring (uneven hooks)Holds 09 in place Deformed
  • Malfunctioning of mechanical spindle
3
  • Fatigue
2
  • Material selection
  • Improper assemblying
5 30
  • Select a stiffer material
  • Reduce stress on spring
Assembly and Reliablity
11 Spring (even hooks) Holds lever to spindle housing Deformed
  • Malfunctioning of mechanical spindle
3
  • Improper handling
  • Fatigue
2
  • Material selection
  • Improper assemblying
4 24
  • Select a stiffer material
  • Reduce stress on spring
Assembly and Reliablity
14 Locking Spring Hides screw in turning wheel Deformed
  • Unable to confine rotation direction of spindle
3
  • Improper handling
  • Fatigue
2
  • Material selection
  • Improper assemblying
4 24
  • Select a stiffer material
  • Reduce stress on spring
Assembly and Reliablity
16 Guide clips for 09 Guides paper on 09 text text
18 Lever Arm Connects spring to spindle Breaks
  • Malfunctioning of mechanical spindle
5
  • Improper handling
  • Improper manufacturing
2
  • Material selection
220
  • Select a stiffer material
Manufacturing and Reliablity
19 Spring Connector Connects two springs to lever arm Breaks
  • Malfunctioning of mechanical spindle
5
  • Improper manufacturing
  • Improper assemblying
2
  • Material selection
  • Mold design
330
  • Select a stiffer material
Assembly and Reliablity
20 Rounded Spring Guide Angles spring to desired measurement Breaks
  • Unable to adjust spring to a desired angle
3
  • Improper handling
  • Improper manufacturing
2
  • Material selection
212

None

Manufacturing
21 Thin Paper GuideGuides paper out of device Breaks
  • Paper ejected in inconsistent direction
  • User dissatisfaction
4
  • Improper handling
  • Improper manufacturing
3
  • Material selection
112
  • Select a stiffer material
Manufacturing
22 Front Spindle Housing Final housing before paper leaves device Fractures
  • User dissatisfaction
2
  • Improper assemblying
  • Improper manufacturing
2
14
  • None
Assembly
23 Spindle Housing Back Back of spindle housing Fractures
  • User dissatisfaction
2
  • Improper usage
  • Incorrect Design/Manufacturing
2
14
  • None
Assembly
24,25 Spindle Housing (L,R) Sides of spindle housing Breaks
  • Improper fit
  • Unable to hold spindle
5
  • Incorrect Design/Manufacturing
1
15
  • None
Assembly
29 White Teeth Guide/ArmGuides cutting teeth in spindle Breaks
  • Malfunctioning of mechanical spindle
5
  • Improper usage
  • Incorrect Design/Manufacturing
3
115
  • Select a stiffer material
Assembly and Manufacturing
30 Cutting Teeth Back of spindle housing Wears/Bends
  • Unable to cut papers
  • User dissatisfaction
4
3
112
  • None
Assembly
31,32 Spindle Back of spindle housing Warps/Breaks
  • Malfunctioning of mechanical spindle
5
  • Improper usage
  • Incorrect Design/Manufacturing
1
15
  • None
Assembly and Manufacturing

DFE Analysis


Team Member Roles

  • Eric Totong:
  • Chang Keun Jung:
  • James Li-Yang Lee:
  • Nishan Kulatilaka:


References

Retrieved from "https://wiki.ece.cmu.edu/ddl/index.php/Paper_towel_dispenser"
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