MSD P Simple Ink Jetting Station. Preliminary Detailed Design Review 11/24/2015

Transcription

1 MSD P Simple Ink Jetting Station Preliminary Detailed Design Review 11/24/2015

2 Risk Assessment Added: Data loss - rank 9 Hardware loss - rank 27

3 Subsystems Motion 1. X-axis 2. Y-axis 3. Z-axis 4. Motion Control Print Head 5. Print Head Adjustment 6. Print Head Docking Station 7. Bucket Reservoir 8. UV Curing 9. Work Surface 10. XEROX Print Head Driver (Image Loader Board)

4 Xerox Provided Hardware

5 X-axis quotes Bishop Wisecarver 1000mm travel DLS Belt system: $ Lo Pro Belt system: $ Igus 1500mm travel ZLW-1040 Belt system: $787.00

6 X-axis comparison Bishop Wisecarver LoPro Bishop Wisecarver DLS Igus DryLin Cost $ $ $ Max Speed (m/s) Travel (mm) Positioning tolerance (mm) 0.1 unknown 0.2 Max acceleration (m/s2)

7 Acceleration distance Assuming constant acceleration Distance to reach max speed (1.82 m/s) in mm BW LoPro (a = 45 m/s2) BW DLS (a = 25 m/s2) Igus DryLin (a = 10 m/s2) Distance to reach half speed (~1 m/s) in mm BW LoPro (a = 45 m/s2) BW DLS (a = 25 m/s2) Igus DryLin (a = 10 m/s2)

8 Y,Z axes- research into existing systems The existing slide shown on the left best matched the team s requirement for motion in the z axis. However, its price exceeded the budget that had been allocated, as did most slides that fit the requirements for motion in both the y and z axes. Due to heavy prices, the team used an existing system from team P14551 Price of the shown system was $

9 Y,Z axes system This is the final design orientation of the Y,Z axes motion system. The y axis is the stepping direction whereas the z axis is the vertical direction.

10 Y,Z axes contd. Shown to the right is the basic orientation of the print head The print head will likely be attached to the mounting plate with set screws.

11 Y,Z Axis Calculations The motors were capable of 200 steps per revolution The Lead screws had a pitch of 2 mm per revolution Thus the minimum step size for a single step of the motor resulted in a 10 micrometer step size. This value was insufficient, but because the motors could microstep, the limitation of the screw drives was more than compensated for.

12 Feasibility Test on P14551 Y & Z axes Wanted to ensure that the axes could Handle the weight they are expected support Operate with the required accuracy Z-axis passed Feasibility Test and we utilize it in our system Confident that the axis will meet requirements because the material of the slide is very strong and we have powerful motors If the Y-axis is not sufficient the team will make modifications

13 Motion Control - Single Motor Test - Schematic Anaheim Automation 23MD Stepper Motor PNP Transistors: 2N4403 Transistors are for the Motor s Sinking Inputs, Signals from the Arduino Turn the Transistors On and Off Arduino Uno Control +24V from Lab Power Supply

14 Motion Control - Single Motor Test - Programming

15 Motion Control - Single Motor Test - Programming Clock Frequency can be Created by Using the delay() Function in Arduino delay(x) - Creates a Delay of X Milliseconds delaymicroseconds(x) - Creates a Delay of X Microseconds

16 Motion Control - Single Motor Test - Sample Code #define Clock 4 void setup() { pinmode(clock, OUTPUT); digitalwrite(clock, LOW); } void loop() { digitalwrite(clock, HIGH); delaymicroseconds(1000); digitalwrite(clock, LOW); delaymicroseconds(1000); }

17 Motion Control - Needed Controller Needed Number of I/O Pins: 15 Motor Pins (5 Pins Per Motor, 1 Motor Per Axis) 6 Limit Switch Pins (2 Limit Switches per Axis) Encoder, Door Switches, E-Stop, Image Loader Board Arduino MEGA Digital I/O Pins (15 Can be Used as PWM) 16 Analog Inputs Programmed through USB Can be Powered by AC to DC Power Adapter 5V Operating Voltage

18 Motion Control - Pseudo Code Move to Initial Positions Check Door Switches and E-Stop For Loop to Control the Z Axis For Loop to Control the Y Axis For Loop to Control the X Axis Create Clock Frequency to Move at Desired Speed Move a Certain Number of Steps or Until Limit Switch is Hit Move Back to Original Position Move Number of Necessary Steps Move Back to Original Position Move Number of Necessary Steps Move to Docking Station

19 Print head Received print head models from Xerox Design changes focused on two main areas: Bucket reservoir Mounting bracket Original model provided by Xerox

20 Print head - Bucket reservoir Three possible design changes: Sight glass removal Sight glass unsafe for uv applications Alternatively, use amber glass/shielding Addition of rounded bottom Easier cleaning, assembly/disassembly Height reduction Easier cleaning, machining Current Design Altered Design

21 Print head - Bucket reservoir

22 Print head - Mounting plate Yaw Original design already incorporates datum adjustments Pitch/Roll See set screws in image to the right Adjusting one screw affects both pitch and roll at the same time due to V-shape pattern Main focus of redesign is to eliminate this behaviour and isolate pitch and roll Original part provided by Xerox (Datum adjustment points circled)

23 Print head - Mounting plate Pitch Datum adjustment screw pattern changed to L-shape from V-shape *Yaw not shown Now, two of the set screws only control one direction of movement Overall design simplified Pitch/Roll Roll

24 Docking Station On and off system docking possible

25 UV curing power estimation intro Goal of 1 Watt/cm^2 set by benchmarking Phoseon UV curing systems. To find irradiance at any point on work surface: *All equations and figures provided by Dr. David Grimes

26 UV curing power calculation setup Peak irradiance occurs at the point directly below the center of the light source. Here is a simplified equation for peak irradiance. SR - Reduced constant L - Length of bulb h - center of bulb (length divided by 2) d - distance from center of bulb to work surface *All equations and figures provided by Dr. David Grimes

27 UV curing power calculation results Distance from work surface 250 Watt bulb irradianc e (Watt/ cm^2) 4 Watt bulb irradianc e (Watt/ cm^2)

28 UV emitting bulb 250 Watt UV bulb nm spectral range 125 Volts Length 0.61 Diameter R7S Base *Min bulb temp: 750 *Max bulb temp: 950 $60.75 * Benchmarked from bulb with similar characteristics

29 UV curing power supply 120V/208V/240V/277V Core & Coil Pulse Start Ballast Kit $63.75 Includes capacitor and mounting brackets Ballast-Bulb Connection Diagram 15 uf, 400 Volt capacitor

30 UV bulb socket $6.32/socket USHIO, R7s, recessed single contact sockets

31 UV Reflective system $ x 7 Germanium Aluminium Elliptical reflector Dr. Grimes recommended not using a parabolic mirror due to self shielding

32 UV Cooling $ mm 2000 RPM, CFM 12 V

33 UV filtering material 0.04 mm thick 20 x 24 $13.50 Less than 10% transmission below 390 nm

34 UV light control schematic $16.89 circuit total Protects the microcontroller from high voltages used to power lamp Difficulty simulating, plan to build and test the circuit

35 UV curing system mounting

36 BOM

37 Thank you! Questions?