1. Electrophotographic Cascade Development Test Rig
Detailed Design Review
November 18th, 2014
Dalton Mead
Michael Warren
Thomas Wossner
Bridget Kearney
Ruishi Shen
Zachary Foggetti

2. Brief Background Electrophotography - How a laser printer works
Why do we need this
documentation purposes
visually show the flow of how the device works from the overall system standpoint
visually demonstrate where the improvement opportunities are and why we need a new design
For example the angle adjustment and gap adjustment of the current device is arbitrary however we would like to utilize some calculations to better support the flow of particles
marks the improvement opportunities (marked in red boxed and lines in the diagram)
provides a template of time collections of current steps
During the next/last phase we will be doing more time studies to finalize the time needed for current device
Also doing time studies for our new design is part of our MSD II project plan
This is for comparison purposes
We have a video showing the whole process (current)
Both of this diagram and the video will be posted on Edge

3. What are we looking for today?
Discuss any risks we may not have thought about
Thoughts from new points of view
Initial reaction on the viability of what we are proposing
Why do we need this
documentation purposes
visually show the flow of how the device works from the overall system standpoint
visually demonstrate where the improvement opportunities are and why we need a new design
For example the angle adjustment and gap adjustment of the current device is arbitrary however we would like to utilize some calculations to better support the flow of particles
marks the improvement opportunities (marked in red boxed and lines in the diagram)
provides a template of time collections of current steps
During the next/last phase we will be doing more time studies to finalize the time needed for current device
Also doing time studies for our new design is part of our MSD II project plan
This is for comparison purposes
We have a video showing the whole process (current)
Both of this diagram and the video will be posted on Edge

4. Outline Process Flow Diagram Designs for Each Subsystem: Hopper
Transfer Surface
Development Zone
Angle Adjustment System
Recirculation System
LabVIEW Program Outline
Flow Down Diagrams
Budget Considerations
Project Plan
What We’ve Learned
Why do we need this
documentation purposes
visually show the flow of how the device works from the overall system standpoint
visually demonstrate where the improvement opportunities are and why we need a new design
For example the angle adjustment and gap adjustment of the current device is arbitrary however we would like to utilize some calculations to better support the flow of particles
marks the improvement opportunities (marked in red boxed and lines in the diagram)
provides a template of time collections of current steps
During the next/last phase we will be doing more time studies to finalize the time needed for current device
Also doing time studies for our new design is part of our MSD II project plan
This is for comparison purposes
We have a video showing the whole process (current)
Both of this diagram and the video will be posted on Edge

5. Process Flow Diagram Why do we need this documentation purposes
visually show the flow of how the device works from the overall system standpoint
visually demonstrate where the improvement opportunities are and why we need a new design
For example the angle adjustment and gap adjustment of the current device is arbitrary however we would like to utilize some calculations to better support the flow of particles
marks the improvement opportunities (marked in red boxed and lines in the diagram)
provides a template of time collections of current steps
During the next/last phase we will be doing more time studies to finalize the time needed for current device
Also doing time studies for our new design is part of our MSD II project plan
This is for comparison purposes
We have a video showing the whole process (current)
Both of this diagram and the video will be posted on Edge

6. Storage System “Hopper”
Function
Store particles before test
Capture particles being recirculated
Control Mass Flow Rate
automated
(replace below with assembly of hopper)

7. Connection to Transfer Surface
Vertical Pivot Mount
Calculated at COM of Hopper
Will always hang vertical due to COM
Allows flexibility of angle for experiment
1/4” diameter will be strong enough

8. Hopper Connection Exploded Concept

9. Mass Flow Rate Control Linear Actuator
Slide open door at bottom of Hopper
Only needed to push/pull 3.8 N of force
Still waiting on quote (similar cost between $200-$450)
Mounted on side of Hopper
Controlled by Labview UI

10. Next Steps Work with Recirculation for correct transfer system
Design Motor Mount System
Finalize linear actuator choice
waiting on companies response

11. Action to Minimize Risk
Risks of Hopper ID
Risk Item
Effect
Failure Mode
Likelihood
Severity
Importance
Action to Minimize Risk
Owner 1
Toner leaks through the door
loss of initial toner onto dev. zone
Non sealed door 2
Add malleable material to seal edges, material that the particles won’t stick to
Dalton
Motor is a little pricey, haven’t got quote yet
More Searching
Exceed budget
Proper shopping and calling companies

12. Bill of Materials 4”x4”x12” square aluminum tube
1/4”-1/2” Inner Dia. Bearing
1/4”-1/2” Aluminum Rod (matches bearing I.D.)
1/4” aluminum plate (stirrup, door, motor casing)
Linear Actuator

13. Transfer Surface

14. Transfer Surface Inspired by a panini grill
Opens completely for user to expose the face of each surface
Allows for easy access of removable development zone
Inhibits movement of plates, relative to each other

15. Development Zone Two surfaces in parallel
3 in. x 3 in.x 0.12 in. aluminum plates surrounded by ¼ in. of insulating material inserted on the plastic transfer surface
Polarity of both plates can be changed to positive or negative
Electrical field between the two plates allows electrophotography to take place
Charging both plates will allow for experimentation with the separation of toner from the carrier beads

16. Removable Aluminum Insert
Plates will be easily removable for inspection of test results
Aluminum plate will act as a removeable insert
Insert will be pressed flush to the transfer surface using a spring contactor tab
Spring tab will have two functions
Press insert flush to transfer surface
Transfer electric charge to the aluminum insert

17. Parallel Spacing Between Plates
Space must be big enough for both toner particles and carrier beads to flow through freely
According to the field intensity formula, E=v/d
If the space is too small, the carrier beads may begin to develop
If the space is too large, the toner particles may not develop at all
A plate gap of approximately 2mm is desired to begin testing toner particles with 90μm
Gap will be adjusted by means of motor
automation and use of adjustable, parallel
shims mounted on theleft and right sides of each plate

18. Parallel Spacing Between Plates
Adjustable, steel, parallel shims
Easily expand and contract to desired size in opening
Exact size can be set with micrometer
Lock desired size by set screws
Range in height from ⅜ in. to 2.25 in.
¼ in. thick
Range in length from 1.77in to 7.5 in,
Available for purchase online from Little Machine Shop

19. Automation of Plate Spacing
Automate spacing between parallel plates using a 12V DC linear actuator
Motor is mounted to the top surface of the top plate and connects to the parallel shims via metal brackets
Vertical gap distance required for adjustment is approximately 2 mm (<.1 in.)
Adjustable Parallel sets have a slope of approx. ⅕, so minimum stroke required is about .5 in.
PA LINEAR ACTUATOR (STROKE SIZE 2", FORCE 200 LBS, SPEED 0.94"/SEC)
STROKE: 2 INCH
FORCE: 200 LBS
SPEED: 0.94"/SEC

20. Action to Minimize Risk
Risks of Development Zone and Transfer Surface ID
Risk Item
Effect
Failure Mode
Likelihood
Severity
Importance
Action to Minimize Risk
Owner 1
Voltage arching between the two parallel plates
Shock injury, damage to device, exhaust hood or nearby equipment
Misuse of power source 2 3
Practice caution when using the device at all times
Bridget
Alumnium plates not flush to plastic
Buildup of toner particles on edges
Spring contactor tab loosens 3
Motor malfunctions
Development zone not set correctly
Failure of motors to work 2
Bridget

21. Development Zone and Transfer Surface BOM
2 Aluminum plates (3in. X 3in. X 0.12in.)
Insulating material
Parallel “shims” (varying in size)
Plastic Surface
12V DC Linear Actuator
Hinge Materials
Spring Contactor Tab

22. Angle Control System
Chosen method: Motorized rack/pinion arm

23. Reasoning Rack rests on ground surface -- prevents slipping
Low torque required to hold position
Stepper motors inexpensive

24. Requirements
Must be able to generate enough torque to hold position or raise transfer surface angle (est: 11 Nm for hold)
Gear teeth must not slip
Should minimize space necessary under transfer surface
Lift arm must bear some load

25. Design Process

26. Design Process Assumptions: mS = 15 kg mA = 1 kg d1 = 4” d2 = 9”
45° ≤ Θ ≤ 80°
This leads to a holding torque of appr Nm

27. Feasibility Technical: Motors with the required power exist
Motor heat should not be a problem
Fabrication:
Motors with estimated torque are available
Simple rack/pinion setups are also available

28. Potential Part Solutions
Motor: Kollmorgen KM series
Rack/pinion gearing: McMaster-Carr
Lift arm: machined aluminum (stock from McMaster-Carr)

29. Angle Adjustment Risks
Risk ID #
Risk Item
Risk Category
Effect
Failure Mode L S I
Action to Minimize
Owner 1
Pinion gear cannot support load
Product risk
Angle adjustment / holding becomes impossible
Design failure 3
Ensure proper gears are selected
Mike 2
Lift arm deforms under load
Angle adjustments become inaccurate / impossible
Ensure materials properties and geometry are appropriate
Motor has insufficient power
Raising / maintaining angle becomes impossible
Ensure motor to be purchased is sufficiently powerful 4
Purchase parts are too expensive
Project risk
Project goes over budget
Logistics failure
Ensure that all parts to be purchased are affordable
All

30. Angle Adjustment - Next Steps
Determine prices for potential purchase parts
Determine mass properties of design’s components
Determine motor torque required

31. Recirculation System 2 Components: Screw Conveyor (Primary)
Manual (Secondary)

32. Why Both Systems? Screw system is a lofty goal
Manual system provides reliable backup
At very steep angles (>70 degrees), screw becomes unreliable

33. Needs
Screw Conveyor:
-Needs to move 1.3L/min of toner at a 70 degree slope
-Must not strip particles of charge → must be insulative
-Must not be so large that it interferes with testing
Manual System (Bucket):
-Must maximize the run time before recirculation is required (>1 min)
-Must prevent particle overflow

34. Well that sounds nice, but this screw thing is hard to visualize...
(1:43)

35. Optimal Screw Conveyor Design - An Overview
“The Turn of the Screw: Optimal Design of an Archimedes Screw” by Chris Rorres (Journal of Hydraulic Engineering, Jan. 2000)
Based on outer dimensions (screw radius, slope, length), optimal inner dimensions (shaft radius, pitch, # of blades) can be calculated

36. Optimal Screw Conveyor Design - An Overview

37. Screw Conveyor Design Dimensions Set by Us: L=Length of Screw: 20’’
𝛂=Angle between centerline & edge of screw
(must be greater than slope of conveyor): 70o
Ro=Radius of Screw: 1.4’’
Calculated Optimal Dimensions
Ri=Radius of Shaft: 0.75’’
# of Blades: 3
Pitch: 2.17’’

38. Design Feasibility - Screw
Fabricate-ability
For the sizes we will need:
-Can buy solid PVC rods (McMaster-Carr, ~$80)
-Can machine into auger/screw shape (acc. to Rob Kraynik in the ME
machine shop)
-Can buy PVC pipe from any hardware store (i.e. Lowes, ~$6)
-Can buy small DC motor (McMaster-Carr)
Technical Feasibility
-Similar systems commonly used to move powder, water
-At 70 degree slope, benchmark particle movement rate of 1.3L/min is
71 RPM

39. Manual Design Internal Dimensions: h=Height: 6’’ w=Width: 4’’
d=Depth: 4’’
t=Material Thickness: 1/8’’
Volume = hwd = 96in3 = 1.6L
-Slightly larger than hopper
-Ensures no overflow

40. Design Feasibility - Bucket
Fabricate-ability
-It’s a bucket, so not difficult
Technical Feasibility
-Volume of 1.6L is slightly larger than hopper, preventing overflow
-At benchmark flow rate of 1.3L/min, recirculation interval is ~1min 20sec

41. Recirculation System Risks

42. Next Steps for Recirculation System
Continue POC for screw conveyor
Decide on motor to turn screw
Finalize BOM, costs
Interfacing/connections with hopper, transfer surface

43. LabVIEW Program Outline

44. Requirements Flow Down Diagram 1
Requirements linkages between CRs, ERs, and Functional Decomp
This helps us better understand the CRs (why customers are requiring this), ERs (why We are requiring this), and the system level functional decomposition
Note that there are two ERs that are not supporting the Functional Decomp based on this diagram
Number of pinch points
Safety score
This is because these two requirements are constraints instead of the support of the functionality of the system
It doesn’t mean these two ERs are not necessary; it only means that they are needed to ensure the safety of our project
Ideally all ERs should support some functionality of the system
Please refer to the pdf file on Edge for better reading purposes (this is only an example to show what we did and what our thought process is to understand the whole system)

45. Requirements Flow Down Diagram 2
Requirements linkages between Functional Decomp and Subsystems
This helps us better understand the how our design for subsystems are supporting the desired system level functionalities
Note that there are two functionalities are not supported by our subsystems
Allow cleaning
Prevent particles clumping
This is because……(explanations)
Please refer to the pdf file on Edge for better reading purposes (this is only an example to show what we did and what our thought process is to understand the whole system)
More details will be added on the right side of the diagram as we finalize our BOM list with the accurate price and part name/number

46. Budget Estimation - HOQ Phase II
Our thought on this:
In QFD I, we analyzed the correlation between CRs and ERs and calculated the relative weight/importance of each ER
Similarly, we use the same methodology
Instead of having CRs in the rows, we now have ERs in the rows
Instead of having ERs in the columns, we now have general BOM list in the columns
The purpose of this is to analyze the correlation of each BOM with the ER (i.e., what ERs is this component supporting and what are the level of correlation? Is this large or small?)
It helps us understand the linkages between the BOM we choose and the ERs from the system standpoint
Once the raw score and the relative worth are calculated for each component/general BOM, we now can see which component is the most important one
This means we should spend more time doing research when choosing those materials because they are critical to our design
For the components with relatively lower relative worth, we know that is where we can put some trade-offs if there is any budget constraint
This budget estimation file will be uploaded on Edge.

47. Budget Estimation - Results from HOQ
This is the pareto chart we came up with based on the relative worth of each BOM
As shown in the graph
Small Motor for the recirculation system is the most “important” BOM as the recirculation system is very important in our design
In order to ensure the system is able to transfer particles using electrophotography, development zone is very important
Therefore the parallelism of the plates and a steady structure of the development zone is key - which conforms with what’s shown in the graph - the shims that are controlling the gap as well as the parallelism of the plates are fairly important in our system
This graph shows us which BOM worth more time and more research
In contrary, for the relatively “non-important” BOM such as plastic box and plastic plate, we can spend less time doing research on them - which makes sense because those materials are common in the market anyways

48. Project Plan - Budget and BOM
Action items related to budget and BOM for the next phase
Red lines on Gantt Chart - critical path
Critical path contains the critical tasks which have to be completed on time otherwise the whole project completion time will be delayed

49. Project Plan- Sketches & RFD Diagram
RFD = Requirements Flow Down

50. Project Plan- Test Plan & Assy Process

51. What We’ve Learned Be braced for changes in CRs
Thorough project plans are beneficial
High-level system requirements are easily neglected when working at the subsystem level

52. Summary Process Flow Diagram Designs for Each Subsystem: Hopper
Transfer Surface
Development Zone
Angle Adjustment System
Recirculation System
LabVIEW Program Outline
Flow Down Diagrams
Budget Considerations
Project Plan
What We’ve Learned
Why do we need this
documentation purposes
visually show the flow of how the device works from the overall system standpoint
visually demonstrate where the improvement opportunities are and why we need a new design
For example the angle adjustment and gap adjustment of the current device is arbitrary however we would like to utilize some calculations to better support the flow of particles
marks the improvement opportunities (marked in red boxed and lines in the diagram)
provides a template of time collections of current steps
During the next/last phase we will be doing more time studies to finalize the time needed for current device
Also doing time studies for our new design is part of our MSD II project plan
This is for comparison purposes
We have a video showing the whole process (current)
Both of this diagram and the video will be posted on Edge

53. Questions?