Electrophotographic
Cascade Development
Apparatus
Detailed Design Review
December 9th, 2014
Dalton Mead
Michael Warren
Thomas Wossner
Bridget Kearney
Ruishi Shen
Zachary Foggetti
Outline
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Customer Requirements
Engineering Requirements
Process Flow Diagram
Subsystems
o Hopper
o Transfer Surface
o Development Zone
o Angle Control System
o Recirculation System
BOM
LabVIEW Program Outline
Test Plan
Plan for MSD II
Customer Requirements
Engineering Requirements
Process Flow Diagram
Process Flow Diagram
Subsystem: Hopper
Subsystem: Hopper
Subsystem: Hopper
Subsystem Interfacing
Vertical Pivot Mount
○ Calculated Center of Mass of Hopper
○ Will always hang vertical due to COM
● Allows flexibility of angle for experiment
● 1/4” diameter will be strong enough
● Attached to outside edges of Transfer Surface
Subsystem: Hopper
● Linear Actuator
● Slide open door at bottom of Hopper
○ Only needed to push/pull 3.8 N of force
● Mounted on backside of Hopper
● Controlled by Labview UI
PA-14-1-50 MINI LINEAR
ACTUATOR (STROKE SIZE
1", FORCE 50 LBS, SPEED
1.18"/SEC)
STROKE: 1 INCH
FORCE: 50 LBS
SPEED: 1.18"/SEC
Subsystem: Hopper
Risks
Bill of Materials
Transfer Surface & Development Zone
Transfer Surface
Functions:
● Provide structural strength to bear forces of
hopper/lever arm
○
○
Yield strength - 276 MPa
Density - 
2,700 kg/m3
● Electrically conductive for grounding
○
5 times more conductive than steel
● Smooth surface to reduce friction
Transfer Surface
❖ 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 in x & y directions
Transfer Surface
Hinge mounts
Main top plate
Charged plates
Edges prevent
particle loss
Main transfer
surface
Insulating layer
Transfer Surface
Subsystem Connections:
● Supports structure of hopper
● Closely tied with development zone
● Moved by angle control system underneath
● Bottom edge leads directly to recirculation
Development Zone
Plate Mating:
Development Zone
Design
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Two surfaces set parallel
3 in. x 3 in.x 0.12 in. aluminum plates surrounded by ¼ in. of insulating material inserted on
the transfer surface
Polarity of both plates can be changed to either positive or negative
○ Charging both plates will allow for experimentation with the separation of toner from the
carrier beads
Removable Aluminium Plates
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Plates will be easily removable inserts for inspection of test results
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Spring tab has two functions:
1. Press insert flush to transfer surface
a. Must be flush to avoid particles getting caught on edge
2. Transfer electric charge to the aluminum insert
a. Screws connect the bottom tab to the transfer surface and top tab to top
plate -- both connected to power
●
Tabs will be made of strip metal in machine shop
Development Zone
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
o If the space is too small, the carrier beads may begin to
develop
o 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
http://www.regentsprep.org
Development Zone
Parallel Spacing Between Plates
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Adjustable, steel, parallel shims
●
Easily expand and contract to desired size in
opening
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Range in height from ⅜ in. to 2.25 in.
Automation of Plate Spacing
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Automate spacing between parallel plates using a
12V DC linear actuator
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Motor is mounted to the top surface of the top
plate and connects to the parallel shims via metal
brackets
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Vertical gap distance required for adjustment is
approximately 2 mm (<.1 in.)
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Adjustable Parallel sets have a slope of approx. ⅕,
so minimum stroke required is about .5 in.
PA-14-1-50 MINI LINEAR
ACTUATOR (STROKE SIZE 1",
FORCE 50 LBS, SPEED 1.18"/SEC)
STROKE: 1 INCH
FORCE: 50 LBS
SPEED: 1.18"/SEC
Development Zone
Movement Setup:
Development Zone
Plate Distance Actuation Animation
Development Zone
Bill Of Materials
Risks of Development Zone and Transfer Surface
ID
Risk Item
Effect
Failure
Mode
Likelihood
1
Voltage
arcing
between
the two
parallel
plates
Shock
injury,
damage to
device,
exhaust
Misuse of
hood or
nearby
power
equipment source
2
Aluminum
plates not
flush to
plastic
Buildup of
toner
Spring
particles on contactor
edges
tab loosens
1
3
Failure of
linear
actuator,
Linear
Developme power
actuator
nt zone not supply or
malfunctio set
labview to
work
ns
correctly
2
2
Severity
Action to
Importance Minimize Risk
Owner
3
Practice
caution when
using the
device at all
times
Bridget
3
3
Ensure that
plate is flush
before each
test.
3
2
3
Bridget
Bridget
Angle Control System
Angle Control System
Chosen method: Motorized rack/pinion arm
Reasoning:
● Rack rests on ground surface -- prevents slipping
● Low torque required to hold position
● Stepper motors inexpensive
Angle Control System
❖ Generate enough torque to hold position or raise transfer
surface angle (est: 11 Nm for hold)
❖ Gear teeth must not slip
❖ Should minimize space under transfer surface
❖ Lift arm must bear some load
Angle Control System
Assumptions:
mS = 15 kg
mA = 1 kg
d1 = 4”
d2 = 9”
d3 = 2”
d4 = 3”
r = 0.75”
45° ≤ Θ ≤ 80°
Holding torque
≈10.28 Nm
Angle Control System
Subsystem Connections:
● Interfaces directly with the transfer surface
● Structural stability provided by connection with base
Angle Control System
Angle Control System
Bill of Materials:
Rack Gear (McMaster) - $25.39
Pinion Gear (McMaster) - $23.00
Stepper Motor (Kollmorgen KM series)
Aluminum bar stock (machined in shop)
Pin connections
Ball Bearing (McMaster) - $4.57
Angle Control System
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
1
3
3
Ensure proper
gears are
selected
Mike
2
Lift arm
deforms
under load
Product
risk
Angle
adjustments
become
inaccurate /
impossible
Design
failure
1
3
3
Ensure
materials
properties
and geometry
are
appropriate
Mike
3
Motor has
insufficient
power
Product
risk
Raising /
maintaining
angle
becomes
impossible
Design
failure
1
3
3
Ensure motor
to be
purchased is
sufficiently
powerful
Mike
4
Purchase
parts are
too
expensive
Project
risk
Project goes
over budget
Logistics
failure
2
2
4
Ensure that
all parts to be
purchased
are affordable
All
Recirculation System Design
Two components:
1. Automated System (Screw Conveyor)
2. Manual System (Buckets)
Why both systems?
1. Manual system provides reliable backup
2. Calculations show that screw becomes unreliable at
steep angles (>70 degrees)
Recirculation System - Flowdown
Recirculation System - Screw
Needs:
1. Move 1.3L/min of particles at a 70 degree slope
2. Must not strip particles of charge → must be insulative
3. Must not be so large that it interferes with testing and/or exceeds space
constraint
Design:
1. L=Length of Screw: 26’’
2. 𝛂=Angle between centerline & edge of screw
(must be greater than slope of conveyor): 70 deg.
3. Ro=Radius of Screw: 1.4’’
4. Ri=Radius of Shaft: 0.75’’
5. # of Blades: 3
6. Pitch: 2.17’’
Design Feasibility - Screw
Fabricate-ability
For the sizes we will need:
-Can buy solid PVC rods
-Can machine into auger/screw shape (acc. to Rob Kraynik in the ME
machine shop)
Technical Feasibility
-Similar systems commonly used to move powder, water
-At 70 degree slope, benchmark particle movement rate of 1.3L/min is
achieved @ 71 RPM
Recirculation System - Buckets
Needs:
1. Must maximize the run time before recirculation is required (>1 min)
2. Must not strip particles of charge → must be insulative
3. Must not be so large that it interferes with testing
4. Must prevent particle overflow
5. Must “dam” particles while bucket is not present
Design:
1. 2 buckets (one small, one large) made from plexiglass
2. Small bucket funnels particles into large bucket
3. Small bucket can be plugged to contain particles while manual recirc
occurs
4. Large bucket drains into screw and can be sealed
5. Large bucket - holds up to 1.6L of particles when sealed
a. when not sealed, funnels into opening in screw
Manual Design
Top Bucket
Internal Dimensions:
-h=Height: 2’’
-w=Width: 6’’
-d=Depth: 4’’
Sloped bottom
Volume = hwd = 48 in3 = 0.8L
-User has ~40 sec to perform manual recirc
Bottom Bucket
Internal Dimensions:
-h=Height: 4’’
-w=Width: 3’’
-d=Depth: 6.5’’
Volume = hwd = 96 in3 = 1.6L
-Ramp to funnel particles into screw
-Slightly larger than hopper
-Ensures no overflow
-Insert slider to seal large bucket
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
Recirculation System
Connections:
1. Hopper
a. Screw rests in semi-circular cutout on top of hopper; Particles drain
from screw into hopper
b. Bucket can be manually dumped into hopper
2. Transfer Surface
a. Bucket hinged to transfer surface
b. Funnels particles into large bucket
c. Bucket funnel is plugged to stop flow while manual recirculation
occurs
d. Particles flow through rectangular cutout in large bucket into screw
e. Screw is fastened to ground
Recirculation System
Parts required for subsystem:
1. 3’’ Diameter, 5’ long PVC rod
2. 198 RPM, 6.3 ft-lb gearmotor
3. 2’x3’ plexiglass sheet
4. 2.75’’ ID PVC pipe
5. Sliders to plug buckets
Parts required to connect to other subsystems
1. Hinge
Recirculation System Risks
BOM
LabVIEW Program Outline
Test Plan
Project Checklist:
MSD I Unfinished
● Finalize and document build procedure and
assembly process
● Format and organize all drawings/sketches
● Start filling out the purchase forms
● Update Edge
Project Plan - MSD II
Summary
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Customer Requirements
Engineering Requirements
Process Flow Diagram
Subsystems
o Hopper
o Transfer Surface
o Development Zone
o Angle Control System
o Recirculation System
BOM
LabVIEW Program Outline
Test Plan
Plan for MSD II
Questions?