Download presentation
Presentation is loading. Please wait.
Published byMitchell Milo French Modified over 6 years ago
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?
Similar presentations
© 2025 SlidePlayer.com Inc.
All rights reserved.