Zeus Laser Engraver

Travis Helling & Viraj PadteECE561 Embedded Systems Design12/13/2015

Content• Introduction• Execution Timeline• Hardware

▫ Frame Assembly▫ Laser Module▫ Control box

• Software▫ Numerical Control and G-codes▫ GRBL firmware▫ Image to Gcode▫ Gcode sender GUI

• Project Cost Analysis• Testing and Verification• Future Work• Conclusion• References

IntroductionThe main goal of this project was to design, build, and operate a CNC laser engraver. This embedded system required a great deal of electrical, mechanical, and software engineering to successfully transfer a digital image onto a wooden media.

2015

Today

Sep Oct Nov Dec

System design9/9/2015

Driving the motors10/15/2015

Building the frame10/30/2015

Mid sem report10/31/2015

Gcode testing on the frame10/31/2015

Drawing a line10/31/2015

Drawing simple shapes11/3/2015

Building the control box11/22/2015

Burning shapes using Boolean type laser triggering 11/30/2015

Gcode to raster using inkscape12/1/2015

Modifying the open source implementation of GrblController 12/5/2015

Ordering parts9/18/2015

Driving the laser10/12/2015

Drawing the curves11/5/2015

Developing a zenity based interface for the inkscape plugin

12/7/2015

9/5/2015 9/18/2015Design

9/19/2015 10/31/2015Development Phase - I

10/27/2015Testing Phase - I

10/31/2015

10/31/2015Development Phase - II

11/15/2015

11/16/2015Testing Phase - II

11/23/2015

11/22/2015Development Phase - III

12/7/2015

Execution Timeline

HardwareFrame AssemblyLaser ModuleControl Box

Hardware: Frame AssemblyExtrude aluminum V-channel rails

▫ 20x40x500mm▫ Built is a standard square formation with

4 stand-off for ground clearance▫ Corner brackets to connect rails together▫ Y-axis moves along the X-axes ▫ Laser module is attached and moves

leaner along the Y-axis▫ Aluminum material allows for the system

to be light

Hardware: Frame AssemblyMotor mounts• 1/8” aluminum plate• Machine mill for precise holes

Vexta stepping motors• Model: C562-9212• 2-phase• 1.8o /step • 4V 1.1A• 0.06mm resolution • Initial motor test video

Axel assembly• 3 wheels in triangle

configuration• 2 wheels on top, 1 on the bottomTiming belt and pulley• There is a GT2 timing pulley on the

axel of the stepper motor• The pitch of the pulley and belt is

2mm

Hardware: Laser Module• Laser driver: Current limited to 1.8amps for laser

protection• Laser toggle circuit: toggle circuit is build with an

ECG291 NPN general purpose medium power BJT• Arduino input signal circuit: Arduino output/input

is 5v at 20-40mA. Using a LM317t voltage regulator to limit the current to 30mA.

• M140 Laser Diode

Initial laser test video(Each circuit has a heat sink for added heat dissipation.)

Hardware: Control Box

Arduino Uno

Synthetos gShield V5

2 x DROK LM2596 DC buck converter

Raspberry Pi 2 B+

SoftwareNumerical Control and G-codes GRBL firmwareImage to Gcode Gcode sender GUI

Hardware: Numerical Control and G-codes

• Numerical control is a method of automatically operating a manufacturing machine based on a code of letters, numbers, and special characters.

• G-code programming originally referred to as the “Word Address” programming format is a popular standard using for sending commands to a CNC machine.

Software: GRBL firmware• GRBL is an open source firmware

used with Arduino platform for implementing gcode interpreter.

• Implementation requires configuration based on mechanical parameters

• A configuration modification was done to range the Spindle ( SXXX) values between 0 and 255 so as to used them for PWM generation

Software: Image to Gcode• Core process on

Inkscape

• Zenity based GUI wrapper for access plugin functionality easily.

Software: Gcode Sender GUI• Simple serial port

application

• Sends g-code one command at a time on the serial port.

• Implemented using open source adaption of the GrblController project.

• Source modified for implementing machine to workspace translation.

Testing and VerificationMiscellaneous testing

Laser heating problemsSmoke handling at the

point of burnTesting for different

types wood

Safety systems testingKill switch with current

protection fuse incorporated in the control box

Testing Phase - ITesting motor driversTesting laser driversManual G-code commands

to GRBL

Testing Phase - IIX and Y positional

accuracy and repeatability Calculation and calibration

of the machine to work space mapping parameter.

Cost Analysis

29%

43%

18%

11%

Total Expenditure = $788.56

Mechanical construction ElectronicsMotors Others hardware components

Future Work•Hardware

▫Limit switches▫Air handling system▫Laser protective case▫Modular head assembly (milling & 3D

printing)▫Live video feed

•Software▫More efficient algorithm for faster

engraving▫User friendly GUI▫Material selection feature▫Remote access capabilities

ConclusionThe goal of this project was to design, build, and operate a CNC laser engraver system. In the end the system was successful in engraver images and photographs into a wooden media. Through this project we learned planning, testing, and team work. A lot of aspects of embedded design were explored while building this complex electro-mechanical project.