ching-han tseng dominic boiko frankie ning harout hedeshian joel meisinger 1
TRANSCRIPT
Design of a 3D printer for affordable prototyping.
Prints each cross section of a 3D object layer by layer
Three axis motion in a 3x3 feet chassis for large scale modeling
Use of accurate stepping motors for high precision printing
Network communication2
25mm/s linear write speed0.5mm deposition resolution5mm3/s (0.3 in3/s)Capable of printing a 10cm3 objectCapable of printing functional
prototypes
3
Motor Controlle
r
Encoder Controller
Extrude Header
Controller
RS422 Bus Interrupt
5V
5V
I/O
12V
Wall
7
CDH Controller
Power
Coordinate all events on printerCommunications interface for
daughter boardsProvide a physical human interface
for high level controlPlatform independent and driverless
communications to host computer
9
ARM Cortex M3(Stellaris
LM3S6965)Main CPU
AVR MCU(ATXMEGA128A1
)IO Hub
SPI4Mb
6-DIN
6-DIN
6-DIN
RS232
DEBUG
Reset linesEthernet
USB->RS232
LCDButto
nsBuzze
r
RS232 I2CGP
IO GPIO
EPS
5V 5->3.3 Buck
5->2.5 Buck RS42
2 Drive
rRS42
2 Drive
rRS42
2 Drive
r
Power Sequenci
ng
10
Choosing the Stellaris: On die Ethernet MAC and PHY Ethernet drivers already written by TI Have working code for MCU from prior
projects Choosing the XMEGA-A1
Cheaper to use XMEGA than purchasing SPI-UART converters.
Allows Stellaris to be bypassed for fallback
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•50MHz ARM Cortex M3• 256KB Flash• 64KB Single Cycle SRAM• On die Ethernet MAC and PHY• 3 x UART• 1 x SPI• 2 x I2C
I/O: ATXMEGA128A
1
• Why the 128 and not the 64: It’s in stock• 32MHz • 128KB Flash• 8KB Single Cycle SRAM• EBI for external buffer memory• 4 x UART• 4 x SPI• 4 x I2C
Stellaris: FreeRTOS uIP Time permitting: lwIP Using a highly
modified Telnet server implementation to provide raw TCP socket for communication.
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• XMEGA:–Mostly interrupt
driven custom firmware
– Simple functionality acting as a “smart” I/O controller.
–May use YAVRTOS
14
Single Price Estimate
Quantity
Stellaris 15 1 30
XMEGA 10 1 10
RS422 Drivers 4 3 12
USB Transceiver 5 1 5
Inter-board connectors 1 3 3
Other connectors 7 1 7
Passives 5 1 5
Other Misc 10 1 10
Total 82
Primary risk: Ethernet non-functional Likelihood of success: 90% [Software working
on dev board, hardware design untested] Fall back to USB-UART
Secondary Risk: USB-UART non-functional Likelihood of success: 6.022E23% [Used
controller IC before and have several working designs using said device]
Fall back to UART on AVR
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Power Supply Provide each sub-system with appropriate power level Maintain UL compliance Isolated Power System
Reduced Shock Hazard Continuity of power Noise Reduction
Over-current and short circuit protection
Wall Outlet120VA
C
5V Forward
converter (Isolated)
CDH
MDC
PSC
SMC
12V Forward
converter (Isolated)
Rectifier Bridge
FPS
EMI Filter
Transformer/Reset Winding
Metallic Enclosure For GroundingRelay(Enable)
Feedback
Isol
ated
Single Price Estimate
Quantity
Full Wave Rectifier 2 1 2
Power Switch 4 1 4
Common Mode Choke 2 1 2
Diode(Rectifier, Vcc, Reset..)
2 4 8
Phototransistor 1 1 1
Bobbin/EE Core 15 1 15
Other Misc 18 1 18
Total 50
RiskPrimary risk: Shock/Explosion Hazard
•Example
•Over-current/short current protection, metallic enclosure grounding and isolation are part of considerations to prevent this hazard
Secondary risk: Components go “Pooof-Hazard” •Hand-made Transformers might not operate as ideal as the calculation•Fall back to more detailed analysis, calculation, component upgrade, and proper circuit protection.
Purpose of Subsystem Lay down the
material of choice (ABS plastic, Epoxy) at a constant rate.
Be able to stop and start new point.
Provide system feedback CDH such as material empty signal and motor error signal.
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CDH
Deposition Motor Driver
EPS
3.3V DC/DC convert
er
12V
MDC FBD
RS422 Driver
5V
Deposition
Thermal Driver
Print head
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XMEGA MCU
ThermalFeedbac
k
Moderate melting point: 221°F, 105°C ABS possesses outstanding impact strength and
high mechanical strength, which makes it so suitable for tough consumer products.
Many colors.
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Risk:• ABS not working for dependable deposition• Nozzle tip temperature not constant
Contingency plan:1.Use other material type such as a epoxy plunger feed.2.Use other tip sizes and materials.
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Part Description Part Number Single Price Estimate
Quantity Total
Microcontroller ATXMEGA64A3 5.47 1 5.47
Motor Driver TB6560AHQ 4.73 1 4.73
RS422 Driver ADM3071EARZ 4.00 1 4.00
RS232 Driver TRS3221E 1.99 1 1.99
Optoisolator LTV-847 1.00 9 9.00
DC-DC Regulator FAN8303MX 1.35 1 1.35
External Oscillator EFJ-N3385xxx 1.00 1 1.00
DB9 connector 1734348-1 1.00 1 1.00
Passives -/- 5.00 5.00
Mechanical -/- 30.00 30.00
Total 63.54
Objective Keep track of extruder head location Keep track of motor movements and
provide limit warnings
Requirements Supply CDH Controller with 3 axis position
of the extruder within 1/200th of a rotation Supply limit warnings and movement
verification to Stepper Motor Controller 27
SMC
CDH
Encoder X
Encoder Y
Encoder Z
EPS
3.3V DC/DC convert
er5VRS422
6 GPIO
PSC
28
RS422 Driver
ISPRS23
2
RS232 Driver
XMEGA MCU
Specs Optical Resolution (>200 count per motor cycle) Fits ACME threaded rod
Considerations Index preferred Quadrature preferred Ease of Mounting/flexibility Max Frequency Response Low Cost
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Part
Supplier
Cost
Resolution(CPR x Quadrecture)
Max Frequency Response
Mounting Signal Integrity
Index
1250DI
Anaheim
70.88
1250x4 100000 Fixed Differential
Yes
500DN
Anaheim
61.60
500x4 100000 Fixed Differential
No
E8P USDigital
37.34
512x4 60000 Custom fit Single Ended
Yes
E5 US Digital
51.50
540x4 60000 Custom fit Single Ended
Yes
500SN
Anaheim
47.95
500x4 100000 Fixed SingleEnded No
Part Description
Part Number
Single Price
Quantity
Total
Microcontroller ATXMega64A3 5.47 1 5.47
Encoder E8P 37.34 4 149.36
RS422 Driver ADM3071EARZ 4 4 16
RS232 Driver TRS3221E 1.99 1 1.99
DC/DC Regulator
FAN8303MX 1.35 1 1.35
External Oscillator
EFJ-N3385xxx 1 1 1
DB9 Connector 1734348-1 1 1 1
Inter-Board Connector
555051-1 2 1 2
Passives -/- 5 1 5
Total 183.17
31
Controller for the three axis stage moving the print head
Drives three 2-phase bipolar stepper motors, one for each axis
Monitor motor current and temperature
Interface with main command and data handling module
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XMEGA MCU
PSC
CDH
Linear Actuator
X
Linear Actuator
Y
Linear Actuator Z
EPS
3.3V DC/DC convert
er5V
RS422
6 GPIO
SMC
RS422 Driver
ISPRS23
2
RS232 Driver
Motor Driver
Motor Driver
Motor Driver
34
Temp sensor
Communication with CDH using RS-422
I/O to Toshiba Stepper Driver IC (TB6560AHQ) that drive the motors
I/O from PSC for motor limits and motor moving information
35
Single 2-phase bipolar motor driver chip Controllable current for torque
management Capable of half stepping and
microsteppingDigital control inputsStepping speed determined by input
clock
36
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Part Description Part Number Single Price Estimate
Quantity Total
Microcontroller ATXMEGA64A3 5.47 1 5.47
Motor Driver TB6560AHQ 4.73 3 14.19
RS422 Driver ADM3071EARZ 4.00 4 16
RS232 Driver TRS3221E 1.99 1 1.99
Optoisolator LTV-847 1.00 33 33.00
DC-DC Regulator FAN8303MX 1.35 1 1.35
External Oscillator EFJ-N3385xxx 1 1 1
DB9 connector 1734348-1 1 1 1
Inter-Board Connector
2 1 2
Passives -/- 5 1 5
Other 10 1 10
Total 91
Current stepper motors might not produce enough torque to move extrude head Very low risk
Current spikes of the motors damaging the microcontroller Low risk with proper opotoisolation
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Task Primary Secondary
CDH Harout Frankie/Joel
EPS Ching Dominic/Joel
MDC Joel Frankie /Harout
PSC Frankie Ching/Dominic
SMC Dominic Frankie/Harout
Mechanical Harout / Dominic/ Joel Ching/Frankie
User Interface Harout Dominic/Frankie
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Category Single Price Estimate
Quantity Total
General 20 3 60
CDH 82 3 246
SMC 91 3 273
PSC 139 3(*) 251
EPS 50 3 250
Board Order 165 3 495
Total: 1575
Financial Support
UROP 800
Halleck Willard Inc. ComponentDonations (200)
Total : 1000