Build and cotrol cnc laser engraving machine

Trang 1 MINISTRY OF EDUCATION AND TRAINING HO CHI MINH CITY UNIVERSITY OF TECHNOLOGY AND EDUCATION FACULTY FOR HIGH QUALITY TRAINING GRADUATION PROJECT ELECTRONICS AND ELECTRONIC ENGIN

OVERVIEW

OVERVIEW

Servo motors have significantly transformed the motion control industry over the past few decades, becoming integral to nearly all automated control systems as industries expand globally As technological advancements elevate demands for labor productivity and product quality—such as precision, responsiveness, and speed—servo motors are increasingly utilized in various automated systems, including robotic arms, CNC machines, and cranes Their advantages, including rapid rotation speed, substantial torque, and high accuracy, coupled with controller feedback mechanisms like encoders, make servo motors essential for meeting the stringent requirements of modern production processes.

Human manual tasks often struggle with achieving the precision required for products with predefined locations To address this challenge, servo motors offer a simplified solution Our team focused on the topic of "CNC laser machines" to deepen our understanding of servo motor control and conduct research in this area.

WHAT IS CNC?

Computer Numerical Control (CNC) refers to an automated system that utilizes specialized programming, known as G-codes, following EIA-274-D standards, to control mechanical processing devices For a CNC machine to operate effectively, the program must be loaded into its advanced computer system, which manages essential components such as the cutting head, cutting speed, and cutting amplitude Various programs are available for efficiently processing products in this automated environment.

CNC machines utilize one or multiple spindles, which are connected to cutting heads like drills or lasers, enabling precise cutting along the vertical (Z) axis The spindle operates at high rotational speeds, while the machine's table secures the product and facilitates movement along the horizontal (X and Y) axes This coordinated movement between the spindles and the table allows for accurate cutting across the product surface.

In the general manufacturing industry, CNC machines have quite a few different types and functions Therefore, the classification also has different criteria:

 According to the type of transmission: electric, hydraulic, or pneumatic

 By control method: point control, segment control, cut line control (2D machine, 3D machine)

 Depending on the tool change technique: rotor-type automatic tool change versus manual tool change

 By operating system: Fanuc, Siemens, Fagor, EMCO,

 In accordance with the machine's number of axes

 Depending on the size and weight of the machine

Some pictures of CNC machines in industry

1.2.3 ADVANTAGES AND DISADVANTAGES OF CNC MACHINES

 CNC machines rely on the content of the software loaded into the machine rather than the operator's skills; the operator primarily just supervises and verifies the machine's operational operations

 High working accuracy; as CNC machines typically have a 0.001mm accuracy, better accuracy can be attained

 High repeatability accuracy and consistent machining quality

 High cutting speed, allowing for better utilization of contemporary cutting materials such hard metal due to the machine's sturdy mechanical design

 Able to run constantly, steadily, and with few faults; • Shorter processing time, saving manpower and labor

 The higher the cost of machine maintenance and repair

 Operating and changing operator is more difficult.

THE IMPORTANCE OF THE SUBJECT

The mold and plastic industries in Vietnam are experiencing significant growth While simple molds can be crafted using hand tools or universal machines, the production of complex molds and machine components necessitates the use of CNC (Computer Numerical Control) machine tools for precision processing.

The Vietnamese market offers a diverse range of CNC machines to address the growing production demands; however, the quality of these machines varies significantly Consequently, it is essential to choose a CNC machine that aligns with specific production requirements to ensure optimal performance and efficiency.

To address the challenging economic landscape, it is essential to develop a CNC machine system tailored for production environments This innovation aims to reduce costs and time while facilitating easier maintenance and repairs, ultimately enhancing operational efficiency.

The project focuses on the design, construction, and operation of a miniature CNC machine to evaluate its accuracy and functionality This initiative aims to provide a more efficient solution and explore a deeper, broader development path for the topic, addressing current urgent needs.

SUBJECT OBJECTIVES

In our project on "Building and Controlling a CNC Laser Engraving Machine," we explored various related topics; however, due to time constraints, we focused on this specific subject to achieve our objectives effectively.

 Apply knowledge, learn, design and manufacture CNC machine models

 Programming, controlling and monitoring CNC machine models to create high- precision products

 Proficient in parameter setting and control on Mach3 software ∙ Troubleshooting when encountering problems.

OBJECT AND SCOPE OF THE PROJECT

 3 Axis CNC Laser Engraving Machine

 3 axis CNC Laser Engraving machine machining on wood and mica surfaces

 ArtCAM Pro and CIMCO V8 software for designing

PROCESS OF IMPLEMENTATION OF THE PROJECT

Following the project's completion, the group came to the following conclusions:

 Learn how CNC machines work

 Read articles and researches on CNC machines

 Find the optimal way to install the x, y, z axes

 Learn about the types of proximity sensors

 Learn how to use Mach3 software

 Draw a block diagram of the system

 Draw the basic circuit diagram

 Design and draw system hardware wiring diagrams

 Install 3 X, Y, Z axes on the model plane

 Construction and installation of voltage sources that need to be supplied to the system

 Install the control circuit for the system

 Write code, load code to test the system

 Perform milling on different workpiece surfaces such as wood, mica

 Test the system at different speeds and accelerations

 Control, check the voltage input and output on the Mach3 board

 Check the vibration of the system, the accuracy of the workpiece when milling

 Write test reports every time you operate.

PROJECT IMPLEMENTATION PLAN

 Field survey: survey of actual CNC machines in a factory producing household wood products

 Learn about CNC machines on the internet

 Using Artcam pro and Cimco V8 software to design and adjust G code

 Manufacturing 3 axis CNC milling machine model

 Use Mach3 software to control and monitor.

SCIENTIFIC AND PRACTICAL MEANINGS

To successfully implement this topic, students need foundational knowledge in electronics, mechanics, informatics, and communication skills, along with proficiency in control software for design and construction This comprehensive skill set enables them to build hardware and write code essential for machining parts Consequently, it provides students with a valuable platform to explore, learn, and gain significant experiences related to their field of study, preparing them for future careers and business opportunities.

Building and learning about a CNC machine provides students with valuable insights that can inspire new research directions and foster innovative problem-solving methods, surpassing the experience gained from simply using an existing CNC machine.

Products that have undergone research and manufacture can aid in the teaching process, meet strict standards for accuracy and aesthetics, and act as a foundation for future improvement.

THEORETICAL BASIS

CNC SYSTEM OVERVIEW

Figure 2 1 Components of a CNC machine system

A CNC machine system as shown in the figure includes the following components:

A personal device, such as a computer, is essential for designers to utilize software that generates programs for CNC machines These programs are typically written in G-code, which outlines the specific steps the CNC machine follows to manufacture each part accurately.

 The device that stores the program segment passed to the machine controller It can be usb, memory card or network

A machine controller is essential for reading and compiling programs that direct machining operations It precisely manages the movement and positioning of the machine's components to optimize cutting time, speed, and depth of cut, ensuring efficient and accurate machining processes.

 Motor controllers (Drivers): receive commands from the machine controller and then operate the motors on the shafts and lasers

 Machine tools: the axes of the machine are driven through the lead screw by the servo motor

Figure 2 2: The concept of a servo system

The command signal originates from the user's computer and is transmitted to the servo's controller Once received, the signal is processed in the servo control section, where the controller manages the movement of the servo motor.

The servo controller receives power and converts AC power to the necessary DC level, supplying the low voltage needed for sensor operation When power is applied to the servo motor, it initiates movement of the load, allowing for adjustments in speed and position.

The positioning controller monitors feedback signals to ensure the servo motor is moving the load correctly If discrepancies are detected, the controller makes necessary adjustments Load management involves controlling position, direction, and speed, which are regulated in relation to a reference command signal using an appropriate error detection device.

ABOUT HARDWARE

Servo motors operate within closed-loop feedback systems, where the motor's output signal is linked to a control circuit As the motor rotates, it continuously sends feedback on its speed and position to this circuit If any obstruction occurs, the feedback mechanism detects that the motor has not reached its intended position The control circuit then actively corrects the error, ensuring the motor achieves the desired point accurately.

The servo motor features a rotor made of a permanent magnet that generates a strong magnetic field Its stator consists of distinct windings that are energized in a specific sequence to facilitate rotor rotation The rotor's movement is influenced by the frequency, phase, polarization, and current in the stator windings, making precise timing and current application essential for optimal performance.

The internal components of the motor: rotary pulse encoder disc, permanent magnet, stator winding

The advantages of this system include stable performance across all speeds, easy rotary speed adjustment, and a wide adjustment range that is both flat and economical It features instantaneous stop capabilities, ensuring the motor halts immediately when the control signal is lost, along with a quick response time Additionally, it allows for large capacity load control mounted on the shaft with a minimal control signal.

+ Disadvantages: High cost Requires adjustment of ring parameters control

Position control method: Using shaft end position detection method Complex configuration (A separate position detector is required) Not easily stabilized due to the influence of shaft movement

Figure 2 5: AC Servo Motor Set MR-J2S

The MELSERVO-J2S series driver features a high-resolution of 131072 pulses per revolution and utilizes a rapid pulse train of up to 500kpps for precise motor positioning, speed, and direction control This advanced system enables smoother starting and stopping, allowing for quick responses to position cues Additionally, a torque limit is implemented on the servo amplifier to safeguard the power transistor from overcurrent caused by sudden acceleration, deceleration, or overload Users can easily adjust the torque limit value by modifying parameters in the controller.

The MR-J2S driver can conduct parameter setting, test operation, monitor status display, and gain adjustment It also includes RS-232C or RS-422 serial communication capabilities

Figure 2 6: Display and function of the amplifier buttons

The MR-J2S controller integrates both a driving circuit and a control circuit to effectively power the HC-KFS Servo motor, which boasts a rated speed of 3000 rpm Additionally, it features a 17-bit encoder that provides precise feedback on the speed and position of the servo motor to the controller.

The internal connection diagram for signal assignment is established in the initial state for each control mode, utilizing a 24V internal power source for supply The connections of the pins are illustrated as shown, with proper grounding implemented.

Figure 2 7: MR-J2S-10A or less controller structure

Figure 2 8: Amplifier internal wiring diagram

Sign Symbol name Sign Symbol name

VDD Internal 24VDC TLA Torque limit

COM The negative pole of the 24V internal source

CR Clear LG Common control pins

SON Servo-on RD Ready

TL Torque limit ALM Alarm

RES Reset ZSP Zero speed

EMG Emergency stop LA Phase A pulse encoder

LSP End of forward rotation LAR

LSN End of reverse rotation LZR Z phase pulse encoder OPC Turn on the input source of the pulse transceiver

NP Pulse signal PP Forward rotation pulse and

PG Input source signal OP Z phase pulse encoder (Open collector)

LBR Phase pulse encoder B SD Grounding

LB SG Common signal pin

Table 2 1: Symbols and names of symbols in the connection diagram inside the controller

 The input command pulses can be any of two different forms, positive or negative logic can be selected Set the pulse command sequence format in parameter number 21

Table 2 2: Input the servo rotation direction command pulse sequence

Figure 2 11: Input voltage for Servo-ON -Assume the input waveform is set to positive the rotation pulses high forward and reverse (parameter number 21 has been set to 0001)

+The pulses are interpreted as follows:

Figure 2 12 Rotation direction control pulse signal

Go to the display screen after power on Select jog operation/operation without motor according to the following procedure:

Figure 2 13: Servo operating procedure idling

 Jog operation: jog operation is performed in the absence of commands from external command devices

To initiate the jog operation, connect the EMG-SG and VDD-COM for internal power usage To operate the servo motor, press and hold the "UP" or "DOWN" button, and switch off the power to stop the motor.

 Function of up and down buttons in jog:

Up Press to start forward rotation (CCW)

Power off to stop Down Press to start reverse rotation (CW)

 End jog operation: To end jog running, power off once or press "MODE" button to go to next screen and then press "SET" button for 2 seconds or more

 Servo system with auxiliary devices:

2.2.3 BOB MACH3 USB CNC CIRCUIT BOARD

The BOB MACH3 USB CNC circuit interfaces with Mach3 software via USB, enabling simultaneous control of four servomotors through X, Y, Z, and A pulse inputs It also accepts signal inputs IN1, IN2, IN3, and IN4, while providing output signals through OUT1, OUT2, OUT3, and OUT4 To ensure circuit board safety, these signals are isolated using Opto and buffer ICs With a maximum pulse frequency of 100 KHz, the circuit is compatible with both servomotors and stepper motors, and it includes an emergency stop (Estop) feature for added safety.

The circuit is designed to accommodate an electronic handwheel and operates on a 24V DC power supply, ensuring stable performance It features an emergency input for added safety and isolates the USB and external ports to enhance system reliability Additionally, the circuit provides a 0-10V output, allowing for spindle motor speed control via Mach3 software.

Figure 2 14: Servo system and auxiliary devices

Figure 2 15: Actual 4-Axis MACH3 USB Board 2.2.4 SERVO SYSTEM AXES AND WORKPIECES

The servo motor system consists of three axes with specific dimensions: the X axis measures 280mm, 60mm, and 45mm; the Y axis measures 210mm, 50mm, and 42mm; and the A axis measures 160mm, 40mm, and 30mm These axes play a crucial role in securing the servo motor, with the Y axis facilitating the movement of the workpiece and the A axis operating along the X axis The workpiece table features a working plane area of 110mm x 70mm and is constructed from a durable 3mm thick aluminum profile Additionally, the screws on the axes effectively convert rotary motion from the servo motor into linear motion.

Mach3, developed by Art Soft USA, is a powerful simulation software that operates on computers It generates pulse signals via the USB port, which dictate the rotation direction and angle for servo motor drivers, enabling precise motor control and rotation.

Figure 2 17: Mach3 software interface + Mach3 software provides the following control features:

 Simulate all functions via computer

 Use computer as a full-featured 6-axis CNC machine controller

 Generating G-code via Wizards or Lazy Cam

 Can control many switching relays

 Capable of generating dynamic speed control pulses completely according to user preferences

 Customize M-code and Macros using VBscript

 Manually control the speed of the crankshaft

 Display simulation image when the machine is running

 Capable of using touch screen

 Emergency (Reset) button to stop the machine in an emergency

 There is a home confirmation switch, axes limit switch

 The connections from the machine to the mach3 are all through the USB port

+Installation instructions on Mach3 CNC software:

 Step 1: Set the unit of measure:

From the MACH3 interface screen go to Config/Select Native Units

Select the unit of measurement in mm

Figure 2 18: Select unit of measure

Select LPT port and Kernel pulse rate

Note: Remember to press the Apply button after each installation step, so that Mach3 saves the parameters that you have just installed

Set pulse output pins for X, Y, A axes

Figure 2 21: Signal settings Figure 2 20: Setting pulse output pins

Estop emergency stop push button setting:

Figure 2 22: Setting the emergency stop button Estop

 Step 3: Setting the base step for the table of axes, velocity, acceleration, and deceleration:

An important parameter of a CNC machine is the base step of the table machine

To inform the software about this parameter, you do the following:

- Go to Config/Motor Tuning:

- Accurately declare the following parameters:

 Steps Per: Number of pulses per 1 mm (This is the base step of CNC machines)

 Velocity: Speed of the computer table in mm/min

 Acceleration: Acceleration of the computer desk in mm/s/s

Figure 2 24: Command operation window Figure 2 23: Mode for spindle

+ In this window there are 2 commonly used features:

 Local System Rotate: During the machining process, the shaft system can be rotated to match the workpiece

 Input: Move to the desired coordinates by typing G0

G-Code is the name of an application programming language in numerical control (also known as NC or Numerical Control) G-Code is often used in automation, computer-aided automation (also known as CAE or Computer Aided Engineering) Sometimes G-Code is also known as G programming language G-Code is a programming language that through tools and devices it can notify and give commands to devices (CNC machines) to know how to move, at what speed, what device to turn on/off, how the trajectory moves The most common application here in CNC is to control the movement of the spindle or the workpiece or both with the purpose of cutting off the excess parts of the workpiece in order to create a product with the required shape

+ G-Code has 02 main command groups: G command group & M command

 A command that specifies the movement (Geometric Function)

 Is the command that specifies the working mode of the machine

 The G instruction is encoded from G00 to G99, each with its own functions and requirements

 Is a command that regulates auxiliary functions such as starting, stopping, ending, turning on and off a few other functions such as water pump, laser

 The M instruction is encoded from M00 to M99, each with its own functions and requirements

 With Mach3 also allows us to extend many other M instructions

 Each additional M instruction in Mach3 is a VB instruction (also known as a macro)

Parameters enclosed with the G or M command instruct the machine on the adjacent values and their purposes, such as the distances to be moved or the control of specific devices Common parameters include those that define movement, speed, and operational functions essential for precise machining.

 X, Y, Z, A, B, C are coordinates along the axes

 I, J, K are the coordinates of the center of the arc along the respective axes X, Y, Z

 F is the speed or feedrate

 S is the milling speed of the spindle

Some G-code commands are summarized as follows:

The G0 command enables rapid movement of the machine along X, Y, Z coordinates or A, B, C axes without engaging the workpiece material This command allows for swift positioning at the maximum speed achievable by the machine.

 Often used to quickly move between areas to be machined

Figure 2 25: Illustration for the G0 command Syntax: G0 [X] [Y] [Z] [A] [B] [C]

Meaning: Move quickly to coordinates X0.5, Y1.3, Z10

 G01- Linear Interpolation/Feed (Linear Interpolation/Feed): Is a command to move straight with speed controlled by attached parameter, or previously specified speed parameter Commonly used in machining

Syntax: G0 [X] [Y] [Z] [A] [B] [C] [F] where F is the speed parameter

Meaning: Move to coordinates X0.5, Y1.3, Z10 at a speed of 1000 units/min

 G02 – Circular Interpolation (Circular Interpolation Clockwise) in the forward direction

Figure 2 27: Illustration for the G2 command

Figure 2 28: Illustration for the G3 command

Both commands share the same syntax and usage; however, determining the correct machining plane—XY, XZ, or YZ—can be complex Each machining plane requires different corresponding parameters.

Using G2/G3 with the XZ plane

The start point coordinates are the end point coordinates of the previous command line

X, Y, Z are the coordinates of the destination or the end point

I, J, K are the coordinates of the arc center corresponding to the X, Y, Z axes

R is the radius of the arc

 G17, G18, G19 command to specify the machining plane

The instructions G17, G18, G19 specify the corresponding machining planes as xOy, xOz and yOz

Artcam Pro is a unique CAD/CAM software from DELCAM that allows users to quickly and efficiently create high-quality 3D products from 2D drawings or images

SYSTEM DESIGN

SYSTEM BLOCK CHART

Figure 3 1: System block diagram +Power block: Supply power for the whole circuit, in this topic use 3 sources:

 5VDC for the USB MACH3 board, 24VDC for the sensors and relay, 36V for the laser

The central processing block is responsible for generating control commands and managing system operations It receives input signals from various sources, including sensors, relays, and computers, processes these signals, and subsequently sends control signals to other system components.

 Power block: Controls the servo motors, isolating the control circuit and the loads

 Drive block: Move the axes during motion

 Control block: Use MACH3 software on laptop to control the command pulse level for the central processing unit to control other blocks

The central control unit's input detects the activation of any of the six sensors, enabling it to halt the servo motor or control the relay output for laser operation.

3.2 3 AXIS CNC LASER ENGRAVING MACHINE SYSTEM STORAGE LOGOLOGY

Figure 3 2: Algorithm diagram of 3-axis CNC system

HARDWARE DESIGN

3.3.1 CUBE DIAGRAM OF 3-AXIS CNC LASER ENGRAVING MACHINE:

- Device (2): sources supplied to the system

- Device (3): Relay MY4N and MY2N-J

- Device (4): Limit sensors of servo shafts

- Device (5): Mach3 USB 4 Axis Board

- Device (6): Drivers 1,2,3 of the 3 axes X,Y,A

- Device (7): Servo motor 1,2,3 of X,Y,A shafts

- Device (8): The jacks on the amplifiers of the servo CN1A and CN1B are I/O digital signal connectors CN2 encoder connector of servo

Figure 3 3: Cube diagram of devices

3.3.2 POWER SUPPLY WIRING DIAGRAM OF 3-AXIS CNC LASER

- Using 220VAC 1-phase power supply to power the system

- Use multi-core rigid single wire

- CB1 is the main CB powering and protecting the system

- CB2 and CB3 protect and power 24V for sensors and board mach 3 CNC

- 24V power is supplied to the sensors through BROWN and BLACK

- 12V source is supplied to the laser engraving head

Figure 3 4: Supply diagram of CNC laser engraving machine system

3.3.3 DIAGRAM OF WIRING OF THE CONTROLLER AND SERVO MOTOR

- According to Figure 3.5, the connection between the mach3 computer and the 3 servo motor drivers controls the servos through the isolation buffer board

- Use the XP, XD, YP, YD, ZP, ZD, AP, AD PINS OF THE MACH3 USB board to pulse the pulse receivers of the AC Servo motor driver

Figure 3 5: Diagram of wiring between the controller and the servo motor

3.3.4 WIRING DIAGRAM 3-AXIS CNC LASER ENGRAVING MACHINE SYSTEM

- 24V power is supplied to MACH3 CNC sensors and control circuits via power pins

- The G-code command is exported from the ArtCAM software, then uses CIMCO Edit software to edit the G-code to suit the system

To operate the edited G-code file, utilize Mach3 software, which communicates with the Mach3 board through the USB port to transmit control pulses effectively.

- The NP, NG, PP, PG pins of the CN1A signal connector receive pulses from the board and execute the G-code commands installed in the Mach3 software

The 13 and 14 signal pins of RELAYs 1, 2, 3, and 4 receive 24V power, while the signal pins of sensors 1A, 1B, 2A, and 2B are also utilized Additionally, the 5.9 signal pins of the RELAYs are connected in series and linked to input 1 of the Mach3 CNC board.

- When the sensor does not act (signal pin of the 0V sensor) The switches usually open and close at this time the circuit is cleared

When a 24V sensor signal pin is impacted, it triggers equipotential phenomena that frequently cause the switches to open, resulting in power outages and circuit interruptions This disruption halts the machining operation of the system, and an alarm is activated on the Mach3 software display screen.

Figure 3 6: Wiring diagram 3-axis CNC laser engraving machine system

3.3.5 PROJECTION DIAGRAM USING REALISTIC MODEL SIMULATION

SYSTEM PARAMETER SETTINGS

3.4.1 PARAMETER SETTINGS FOR MACH3 SOFTWARE:

- The Config- Select native Units section selects the unit as mm

- Config- Ports & Pins – Motor outputs select pulse pins control 3 AC Servo motors for

Figure 3 7: Projection using realistic model simulation

- Input Signals section to set the addresses of incoming ports

Figure 3 9: Setting of sensor signalsFigure 3 8: selection of motor control pulse pin

- Choose which input signals to use Use sensors at 2 ends of the axes and 1 Estop

3.4.2 CALCULATION OF THE MOVEMENT PARAMETERS OF THE AXES

One complete rotation of the servo results in a 2mm movement along both the X-axis and Y-axis Consequently, to achieve a 1mm movement on either axis, a specific number of pulses is required.

131072/2 pulses If P3/P4 is 64/1, the number of pulses set in mach3 software for the 1mm displacement motor will be 1024

The A-axis features a spindle connected to a gearbox with a gear ratio of i = 25, yielding 131072 pulses per revolution With a maximum pulse rate of 100 kHz from the Mach3 USB board, we aim to achieve a maximum speed of 20 rpm while maintaining an accuracy of 0.1 degrees The calculation of the gear ratio is crucial for optimizing performance in this setup.

 The maximum speed required is 20 rpm: When the shaft rotates at 20rpm

↔ the engine rotates at 25*20 = 500 rpm

 0.1 degree accuracy: When the shaft rotates with an accuracy of 0.1 degrees, it means that the motor has an accuracy of 2.5 degrees

- Choose CDV = 144 => CMX = ∗ 144 = 1572.8 => chọn CMX = 2048

Figure 3 10: Setting of E-stop signals

To achieve a rotation of the A-axis at a speed of 20 rpm with an accuracy of 0.1 degrees, it is essential to establish a gear ratio Consequently, the number of pulses needed for the axis to complete a rotation of 0.1 degrees amounts to 640 pulses.

Figure 3 12: turning Y-axis motor movement Figure 3 11: turning X-axis motor movement

Figure 3 13: turning A-axis motor movement

Figure 3 14: turning Z-axis motor movement

- Parameter settings in the controller:

- CN1A signal connector pins: PP, PG, NP, NG pins receive pulses

- CN1B PINS: VDD-COM, EMG-SG to remove Emergency signal

- CN2 signal connector pins with Encoder of servo motors: power P5 pins, ground

LG pins, MR, MRR, MD, MDR pins are signal pins that feedback on the amplifier of servo motors

Installation parameters Setting value Function

P0 0000 Selection of position control mode

P1 0012 Input signal noise filtering with pulse width of 3,555ms and selection of electromagnetic brake interlock of CN1B-pin19

P16 0000 Using the RS-232C cable, remove the value when the power is turned off and there is no delay

P18 0001 Show engine speed when powered on

P19 000E Allows referencing and setting the value of all parameters

(one pulse trigger, the direction specified by a digital signal pin (ON, OFF) Save the pulse generator pin Because the computer output uses mach3 software, the pulse signal is pulsed

P41 0111 Servo On, LSP, LSN signals are always activated

Table 3 1: Parameters setting in the controller

Consider parameter P54: Change the direction of rotation of the servo motor

- X-axis servo motor control driver: set value P54:0001

- Y-axis servo motor control driver: set value P54:0000

- Change the direction of rotation of the servo motor for the input pulses

Setting value The direction of rotation of the motor

Input pulse at the forward rotation position

Input pulse at the inverse rotation position

Table 3 2: Change the direction of rotation of the servo pulses

 This means that when the pulse from the MACH 3 USB Board is fed into the drivers, the 2 servo motors will rotate in opposite directions.

DESIGN AND CREATE G-CODE FILES

3.5.1 CREATE IMAGE FILES ON DEMAND USING ARTCAM SOFTWARE:

Figure 3 15: Create image files 3.5.2 SELECT TOOLPATHS FOR THE SHAPE TO BE ENGRAVED:

3.5.3 SELECT THE PARAMETERS IN THE MACHINE VECTORS SECTION TO SUIT THE WORKPIECE:

Figure 3 17: Machine Vectors selection interface

3.5.4 EXPORT G-CODE FILES AND SELECT MACHINE OUTPUT TO SUIT THE SYSTEM:

Figure 3 18: Save toolpath and select output file

3.5.5 USE CIMCO EDIT SOFTWARE TO SIMULATE AND EDIT G-CODE FILES

CONSTRUCTION SYSTEM

WIRE CONNECTION TEST THE OPERATION OF EACH DEVICE

 Wiring for the DC power supply:

Figure 4 1:Wiring for DC power supply

To provide power to the DC power supply, connect 220VAC through the protective circuit breaker (CB), ensuring safety The V+ and V- pins of the DC power supply should then be linked to the power signal pins on the control board for proper functionality.

 Wiring connection between control board and driver and servo motor

 Power the system through protection CBs

The wiring of pulse and direction signals (NP, NG, PP, PG) from the CN1A connector of the servo motor to the pulse feed pins (XP, XD, YP, YD, ZP, ZD) on the control board is facilitated through Domino electricity.

 Connect the U, V, W phases of the servo respectively to U, V, W of the driver

 Connect the EMR signal pins in CN1B of the servo motor

 Connect the CN2 cable to the encoder of the servo motor

 Adjust the parameters in the motor driver

 Declare signal pins in Mach3 software

Figure 4 2: Wiring connection between control board and driver and servo

 Issue commands from Mach3 software to control servo motors

Connect the sensor wire to the control board:

Connect the brown signal wire of the sensor to the positive terminal of the 24V power supply, the blue signal wire to the negative terminal, and the black signal wire to input 1 of the control board.

Set the sensor signal in the Mach3 software Control the shaft to the sensor position so that the impact sensor stops the shaft.

POSITIONING AND FIXING LOCATION OF DEVICES

Based on the vertical projection model to simulate the system (Section 3.2.2) to position the devices into the system

Figure 4 3: Wiring sensor and control board

To properly position and secure circuit breakers (CBs), drivers, and DC power, ensure that the edge of the sole aluminum is approximately 5 cm from where the conduit will be placed Additionally, maintain a spacing of about 3 cm between devices for effective wiring.

The circuit breakers (CBs) are arranged from left to right, with CB1 serving as the main circuit breaker for the entire system, CB2 providing protection for drivers and motors, and CB3 safeguarding sensors The power sources are positioned from top to bottom, starting with the DC 24V power supply, followed by the DC 12V power supply The drivers are sequentially installed, where Driver 1 manages servo motor 1 and Driver 2 oversees servo motor 2.

2, Driver 3 controls the servo motor 3

Drill holes with a diameter of 4mm and use 4mm hexagon screws to fix the devices, CBs use extra rails to attach

 Positioning and fixing the axes:

Figure 4 5: Position the screw hole of the workpiece on the shaft

Screw holes are drilled concentrically with the shaft holes to ensure the workpiece remains fixed during movement, allowing for consistent placement on the workpiece table The screw holes feature a large diameter of 8mm and a small diameter of 4mm Utilizing aluminum profiles for the workpiece tables is advantageous due to their affordability, high rigidity, and integrated rails that secure the workpiece clamp during machining.

The Y-axis is mounted on the aluminum base, while the X-axis is supported above it, with the Z-axis sliding along the X-axis To secure the workpiece on the Y-axis, a 1 cm long, 4 mm hexagonal screw is utilized Drill 4 mm diameter holes to fasten the shafts, which are positioned on the outer edges of the aluminum base for easy workpiece placement Adjustments for attaching the laser are made using the screw, and two proximity sensors are installed on the underside of each shaft, with servos positioned atop the axes.

The Y-axis is placed 13.5cm from the right edge of the aluminum base

 Locating and fixing electrical conduits:

Figure 4 6: Locating and fixing electrical conduit

Conduits are placed at the edge of the aluminum base to save space, facilitate wiring, and look aesthetically pleasing Use a square conduit to thread the wires

Aluminum base has an area of 70x60cm

Figure 4 7: Install the control board

Install the lower control circuit 13cm from the bottom edge of the aluminum base for convenience

Convenient for wiring, connect with USB cable and save space.

WIRE CONNECTION OF DEVICES

 Wire connection for the CBs:

Figure 4 8: Wire connection for the CB

The main CB is connected to the AC 220V input source and in series with the rear auxiliary CBs

 Connect the power supply to the driver:

AC 220V input power is supplied to the drivers via protective CBs

Figure 4 9: Power supply for servo motor driver

Figure 4 10: Connection for DC power supply

Connect the input AC power to the L, N pins of the power supply and connect the V+, V- pins of the power supply to the devices in the circuit

 Press the cos terminal for the wires connected to the device:

Cos and number the devices to ensure continuous conduction, safe insulation and easy inspection and repair when there is a problem The wires are connected via electric dominoes

Figure 4 11: Press the cos end for the wires connected to the device

 Wiring connection for control board:

Figure 4 12: Wiring connection for control board

Connect the signal wires and the DC power supply as the system schematic diagram for the control board

 Overall model of the system:

CHECK THE SYSTEM BEFORE TURNING ON THE POWER

 Check the continuity of the CB:

Figure 4 14: CB continuity check Check continuity of the L and N phase wires

Figure 4 15: Check DC power continuity:

Check the connection of the DC power supply to the circuit board.

OPERATION TEST

OPERATE

 Step 1: Power up the system, check the normal status of the devices

 Step 2: Run JOG, check the operation of the driver and servo motor

Figure 5 2: Select JOG mode on driver

 Step 3: Open Mach3 software, check connection with Mach3 USB board a) b)

Figure 5 3: Mach3 software working screen

Figure 5 4: Checking the input signal a) When the sensor is not active b) When the sensor is active

 Step 4: Insert the workpiece into the workpiece table

Figure 5 5: Fixing the workpiece on the workpiece table

Figure 5 6: Set state (0,0,0) on Mach3

 Step 6: Export G-code from Artcam Pro

Figure 5 7: Artcam pro Software working screen

 Step 7: Edit G-code with Cimco Edit

Figure 5 8: CIMCO Edit working screen

 Step 8: Load G-code file into Mach3 software

Figure 5 9: File G-code on Mach3 interface

 Step 9: Run the program to perform machining on the workpiece

Figure 5 10: Simulate running the program on Mach3

PRODUCT QUALITY CHECK

As the project was being implemented, our team made various observations on the system and the final product

+Depending on the substance of the product being engraved, engraving times will vary:

When engraved with a high feed rate (F00), depending on whether the surface is smooth or ridged, there will be thin lines but it will be difficult to see

When engraved with feed rate (F), the lines will be bolder and clearer, but there will be smudges due to long laser exposure

When engraving on Plexiglas, using lower feed rates results in more aesthetically pleasing and precise lines, as demonstrated in the above sample In contrast, higher feed rates can lead to smeared lines and reduced accuracy, as seen in the below sample.

+ Besides, the system can also engrave many different types of shapes with complex lines and require a longer engraving time

Figure 5 11: Products after engraving on wood and mica surfaces

Our team's laser engraving system demonstrates exceptional stability, consistently achieving near-perfect accuracy after multiple engravings of the same image This reliability is evident when comparing the engraved samples to the original selected image.

CONCLUSION AND DEVELOPMENT

CONCLUSION

After 3 months of research and construction, despite the limited time and expense, the group has completed the set goal of designing and controlling a CNC laser machine, milling and cutting on surfaces such as wood , mica is especially successful with high precision and good aesthetics

The machining and testing results indicate satisfactory accuracy, with an error margin not exceeding 0.5 mm However, our group's design has limitations, including the absence of a Home sensor for axis positioning and the inability to calculate load capacity or vibration We encourage teachers, peers, and friends to provide constructive feedback on our project, enabling us to learn from their insights and improve our design for future development.

DEVELOPMENT

After implementing the project, the group also realized some limitations of the project they were working on, so they proposed some development directions for the project as follows:

To enhance productivity, it is crucial to increase the vitme length of the axes due to the small workpiece area of 70x60 mm By expanding the workpiece area, we can accommodate larger and more complex workpieces, allowing for more versatile operations.

To enhance machining efficiency, it is essential to increase the laser power of the system By replacing the existing low-capacity laser with a higher-capacity option, the machining process will become smoother, resulting in reduced machining times for workpieces.

To enhance the system's performance, it is essential to incorporate additional Home sensors, as the current 3-axis size is relatively small During the initial implementation phase, the Home sensor was not utilized; however, its integration is crucial for optimizing functionality and accurately determining the initial position in future developments.

The USB Mach3 Board V2.0 AKZ 250 offers significant advantages over the existing Mach3 board, including a pulse frequency of up to 200KHz This enhanced performance allows for the integration of more inputs and outputs, enabling the system to receive signals and control a greater range of equipment efficiently.

The current software for adding workpieces offers a wide variety of design options, making it easier to create and process wood surfaces Programs like Aspire allow for personalized design, enhancing user experience To ensure a stable and efficient workflow, it is essential to explore and learn various design software.

[1] Documentation MR-J2S-A Servo Amplifier_ Mitsubishi Electric

[4] Documentation CNC Programming with G-code

[5] Mach3Mill_Install_Config documentation