Ching-Han Tseng Dominic Boiko Frankie Ning Harout Hedeshian Joel Meisinger 1 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 communication 2 25mm/s linear write speed 0.5mm deposition resolution 5mm3/s (0.3 in3/s) Capable of printing a 10cm3 object Capable of printing functional prototypes 3 4 Expected Dimension: 3 ft x 3ft x 3ft 3 stepping motors 5 6 5V Wall Power CDH Controller 5V 12V Motor Controller RS422 Bus I/O Encoder Controller Interrupt Extrude Header Controller 7 Command and Data Handling 8 Coordinate all events on printer Communications interface for daughter boards Provide a physical human interface for high level control Platform independent and driverless communications to host computer 9 DEBUG EPS 5V RS232 Power Sequencing 5->3.3 Buck 5->2.5 Buck ARM Cortex M3 (Stellaris LM3S6965) Main CPU I2C USB>RS232 AVR MCU (ATXMEGA128A1) IO Hub 6-DIN 6-DIN 6-DIN RS232 Ethernet SPI 4Mb RS422 Driver RS422 Driver RS422 Driver Buzzer LCD Reset lines Button s 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 11 I/O: ATXMEGA128A1 •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 • 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 12 Stellaris: FreeRTOS uIP Time permitting: lwIP Using a highly modified Telnet server implementation to provide raw TCP socket for communication. • XMEGA: – Mostly interrupt driven custom firmware – Simple functionality acting as a “smart” I/O controller. – May use YAVRTOS 13 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 14 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 15 Electrical Power System 16 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 EMI Filter Rectifier Bridge Feedback Isolated Wall Outlet 120VAC 5V Forward converter (Isolated) Transformer/ Reset Winding FPS CDH MDC 12V Forward converter (Isolated) PSC SMC Metallic Enclosure For Grounding Relay(Enable) 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 Risk Primary 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. Material Deposition Controller 21 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. 22 MDC FBD EPS 3.3V DC/DC converter RS422 Driver XMEGA MCU CDH 5V 12V Deposition Motor Driver Deposition Thermal Driver Print head Thermal Feedback 23 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. 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. 24 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 25 Position Sensor Controller 26 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 RS232 EPS ISP PSC 6 GPIO SMC RS232 Driver 5V 3.3V DC/DC converter XMEGA MCU RS422 Driver CDH RS422 Encoder X Encoder Y Encoder Z 28 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 29 Part Supplier Cost Resolution (CPR x Quadrecture) Max Frequency Response Mounting Signal Integrity Index 1250 DI Anaheim 70.88 1250x4 100000 Fixed Differential Yes 500 DN Anaheim 61.60 500x4 100000 Fixed Differential No E8P US Digital 37.34 512x4 60000 Custom fit Single Ended Yes E5 US Digital 51.50 540x4 60000 Custom fit Single Ended Yes 500 SN Anaheim 47.95 500x4 100000 Fixed Single Ended No 30 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 5 1 5 Total 183.17 Passives -/- 31 Stepper Motor Controller 32 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 33 EPS RS232 ISP SMC RS232 Driver 5V 3.3V DC/DC converter XMEGA MCU Temp sensor 6 GPIO PSC RS422 Driver Motor Driver Motor Driver Motor Driver Linear Actuator X Linear Actuator Y Linear Actuator Z CDH RS422 34 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 microstepping Digital control inputs Stepping speed determined by input clock 36 37 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 2 1 2 5 1 5 10 1 10 Total 91 Inter-Board Connector Passives Other -/- 38 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 39 40 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 41 Gant chart 42 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. Component Donations (200) Total : 1000 43 44