Attention! Be careful when using lasers. The laser used in this machine may cause vision damage and possibly blindness. When working with powerful lasers above 5 mW, always wear a pair of safety glasses designed to block the laser wavelength.
A laser engraver on Arduino is a device whose role is to engrave wood and other materials. Over the past 5 years, laser diodes have advanced, allowing fairly powerful engravers to be made without much of the complexity of operating laser tubes.
You should be careful when engraving other materials. So, for example, when used in working with laser device plastic will produce smoke which contains dangerous gases when burned.
In this lesson I will try to give direction to the thought, and over time we will create a more detailed lesson on the implementation of this complex device.
To begin with, I suggest you look at what the entire process of creating an engraver looked like for one radio amateur:
Strong stepper motors also require drivers to get the most out of them. In this project, a special stepper driver is used for each motor.
Below is some information about the selected components:
- Stepper motor – 2 pieces.
- Frame size is NEMA 23.
- Torque is 1.8 lb-ft at 255 oz.
- 200 steps/revolutions – 1 step 1.8 degrees.
- Current – up to 3.0 A.
- Weight – 1.05 kg.
- Bipolar 4-wire connection.
- Stepper driver – 2 pieces.
- Digital stepping drive.
- Chip.
- Output current – from 0.5 A to 5.6 A.
- Output current limiter – reduces the risk of motor overheating.
- Control signals: Step and Direction inputs.
- Pulse input frequency – up to 200 kHz.
- Supply voltage – 20 V – 50 V DC.
For each axis, the motor directly drives the ball screw through the motor connector. The motors are mounted on the frame using two aluminum corners and aluminum plate. The aluminum corners and plate are 3mm thick and are strong enough to support a 1kg motor without bending.
Important! The motor shaft and ball screw must be properly aligned. The connectors that are used have some flexibility to compensate for minor errors, but if the alignment error is too large, they will not work!
Another creation process of this device you can watch the video:
2. Materials and tools
Below is a table with the materials and tools needed for the project " laser engraver on Arduino."
| Paragraph | Provider | Quantity |
| NEMA 23 stepper motor + driver | eBay (seller: primopal_motor) | 2 |
| Diameter 16mm, pitch 5mm, ball screw 400mm long (Taiwanese) | eBay (seller: silvers-123) | 2 |
| 16mm BK12 support with ball screw (drive end) | eBay (seller: silvers-123) | 2 |
| 16mm BF12 Ball Screw Support (No Driven End) | eBay (seller: silvers-123) | 2 |
| 16 shaft 500 mm long | (seller: silvers-123) | 4 |
| (SK16) 16 shaft support (SK16) | (seller: silvers-123) | 8 |
| 16 linear bearing (SC16LUU) | eBay (seller: silvers-123) | 4 |
| eBay (seller: silvers-123) | 2 | |
| Shaft holder 12 mm (SK12) | (seller: silvers-123) | 2 |
| A4 size 4.5mm clear acrylic sheet | eBay (seller: acrylicsonline) | 4 |
| Aluminum Flat Rod 100mm x 300mm x 3mm | eBay (seller: willymetals) | 3 |
| 50mm x 50mm 2.1m Aluminum Fence | Any theme store | 3 |
| Aluminum Flat Rod | Any theme store | 1 |
| Aluminum corner | Any theme store | 1 |
| Aluminum corner 25mm x 25mm x 1m x 1.4mm | Any theme store | 1 |
| M5 socket head screws (various lengths) | boltsnutsscrewsonline.com | |
| M5 nuts | boltsnutsscrewsonline.com | |
| M5 washers | boltsnutsscrewsonline.com |
3. Development of the base and axes
The machine uses ball screws and linear bearings to control the position and movement of the X and Y axes.
Characteristics of ball screws and machine accessories:
- 16 mm ball screw, length – 400 mm-462 mm, including machined ends;
- pitch – 5 mm;
- C7 accuracy rating;
- BK12/BF12 ball joints.
Since the ball nut consists of ball bearings rolling in a track against a ball screw with very little friction, this means that motors can run at higher speeds without stopping.
The rotational orientation of the ball nut is locked using an aluminum element. The base plate is attached to two linear bearings and a ball nut through aluminum corner. Rotation of the Ballscrew shaft causes the base plate to move linearly.
4. Electronic component
The laser diode selected is a 1.5 W, 445 nm diode housed in a 12 mm package with a focusable glass lens. These can be found, pre-assembled, on eBay. Since it is a 445 nm laser, the light it produces is visible blue light.
The laser diode requires a heatsink when operating at high levels power. When constructing the engraver, two aluminum supports for SK12 12 mm are used, both for mounting and for cooling the laser module.
The output intensity of a laser depends on the current that passes through it. A diode by itself cannot regulate current, and if connected directly to a power source, it will increase current until it fails. Thus, an adjustable current circuit is required to protect the laser diode and control its brightness.
Another option for connecting the microcontroller and electronic parts:
5. Software
The Arduino sketch interprets each command block. There are several commands:
1 – move RIGHT one pixel FAST (blank pixel).
2 – move RIGHT one pixel SLOW (burnt pixel).
3 – Move LEFT one pixel FAST (blank pixel).
4 – Move LEFT one pixel SLOW (burnt pixel).
5 – move up one pixel FAST (empty pixel).
6 – Move UP one pixel SLOW (burnt pixel).
7 – Move DOWN one pixel FAST (blank pixel).
8 – move DOWN one pixel SLOW (burnt pixel).
9 – turn on the laser.
0 – turn off the laser.
r – return the axes to their original position.
With each character, the Arduino runs the corresponding function to write to the output pins.
Arduino controls engine speed through delays between step pulses. Ideally, the machine will run its motors at the same speed whether it is engraving an image or passing a blank pixel. However, due to the limited power of the laser diode, the machine must slow down at pixel records. That's why there is two speeds for each direction in the list of command symbols above.
Sketch of 3 programs for Arduino laser engraver below:
/* Stepper motor control program */ // constants won't change. Used here to set pin numbers: const int ledPin = 13; // the number of the LED pin const int OFF = 0; const int ON = 1; const int XmotorDIR = 5; const int XmotorPULSE = 2; const int YmotorDIR = 6; const int YmotorPULSE = 3; //half step delay for blank pixels - multiply by 8 (<8ms)
const unsigned int shortdelay = 936;
//half step delay for burnt pixels - multiply by 8 (<18ms)
const unsigned int longdelay = 2125;
//Scale factor
//Motor driver uses 200 steps per revolution
//Ballscrew pitch is 5mm. 200 steps/5mm, 1 step = 0.025mm
//const int scalefactor = 4; //full step
const int scalefactor = 8; //half step
const int LASER = 51;
// Variables that will change:
int ledState = LOW; // ledState used to set the LED
int counter = 0;
int a = 0;
int initialmode = 0;
int lasermode = 0;
long xpositioncount = 0;
long ypositioncount = 0;
//***********************************************************************************************************
//Initialisation Function
//***********************************************************************************************************
void setup()
{
// set the digital pin as output:
pinMode(ledPin, OUTPUT);
pinMode(LASER, OUTPUT);
for (a = 2; a <8; a++){
pinMode(a, OUTPUT);
}
a = 0;
setinitialmode();
digitalWrite (ledPin, ON);
delay(2000);
digitalWrite (ledPin, OFF);
// Turn the Serial Protocol ON
Serial.begin(9600);
}
//************************************************************************************************************
//Main loop
//************************************************************************************************************
void loop()
{
byte byteRead;
if (Serial.available()) {
/* read the most recent byte */
byteRead = Serial.read();
//You have to subtract "0" from the read Byte to convert from text to a number.
if (byteRead!="r"){
byteRead=byteRead-"0";
}
//Move motors
if(byteRead==1){
//Move right FAST
fastright();
}
if(byteRead==2){
//Move right SLOW
slowright();
}
if(byteRead==3){
//Move left FAST
fastleft();
}
if(byteRead==4){
//Move left SLOW
slowleft();
}
if(byteRead==5){
//Move up FAST
fastup();
}
if(byteRead==6){
//Move up SLOW
slowup();
}
if(byteRead==7){
//Move down FAST
fastdown();
}
if(byteRead==8){
//Move down SLOW
slowdown();
}
if(byteRead==9){
digitalWrite (LASER, ON);
}
if(byteRead==0){
digitalWrite (LASER, OFF);
}
if (byteRead=="r"){
//reset position
xresetposition();
yresetposition();
delay(1000);
}
}
}
//************************************************************************************************************
//Set initial mode
//************************************************************************************************************
void setinitialmode()
{
if (initialmode == 0){
digitalWrite (XmotorDIR, OFF);
digitalWrite (XmotorPULSE, OFF);
digitalWrite (YmotorDIR, OFF);
digitalWrite (YmotorPULSE, OFF);
digitalWrite (ledPin, OFF);
initialmode = 1;
}
}
//************************************************************************************************************
// Main Motor functions
//************************************************************************************************************
void fastright()
{
for (a=0; a
6. Launch and setup
Arduino represents the brain for the machine. It outputs the step and direction signals for the stepper drivers and the laser enable signal for the laser driver. In the current project, only 5 output pins are required to control the machine. It is important to remember that the bases for all components must be related to each other.
7. Functionality check
This circuit requires at least 10VDC power, and has a simple on/off input signal provided by the Arduino. The LM317T chip is a linear voltage regulator that is configured as a current regulator. The circuit includes a potentiometer that allows you to adjust the regulated current.
Sometimes you need to sign a gift beautifully, but it’s not clear how to do it. The paint spreads and wears off quickly, a marker is not an option. Engraving is best suited for this. You don’t even have to spend money on it, since anyone who knows how to solder can make a laser engraver from a printer with their own hands.
Design and principle of operation
The main element of the engraver is a semiconductor laser. It emits a focused and very bright beam of light that burns through the material being processed. By adjusting the radiation power, you can change the depth and speed of burning.
The laser diode is based on a semiconductor crystal, on top and bottom of which there are P and N regions. Electrodes are connected to them, through which current is supplied. Between these regions there is a P - N junction.
Compared to a regular laser diode, it looks like a giant: its crystal can be examined in detail with the naked eye.
The values can be deciphered as follows:
- P (positive) area.
- P - N transition.
- N (negative) area.
The ends of the crystal are polished to perfection, so it works as an optical resonator. Electrons, flowing from a positively charged region to a negative one, excite photons in the P-N junction. Reflecting from the walls of the crystal, each photon generates two similar ones, which, in turn, also divide, and so on ad infinitum. The chain reaction occurring in a semiconductor laser crystal is called the pumping process. The more energy supplied to the crystal, the more it is pumped into the laser beam. In theory, you can saturate it indefinitely, but in practice everything is different.
During operation, the diode heats up and must be cooled. If you constantly increase the power supplied to the crystal, sooner or later there will come a time when the cooling system can no longer cope with heat removal and the diode will burn out.
The power of laser diodes usually does not exceed 50 Watts. Above this value, it becomes difficult to make an effective cooling system, so high-power diodes are extremely expensive to produce.
There are semiconductor lasers of 10 kilowatts or more, but they are all composite. Their optical resonator is pumped by low-power diodes, the number of which can reach several hundred.
Compound lasers are not used in engravers because their power is too high.
Creating a laser engraver
For simple work, such as burning patterns on wood, complex and expensive devices are not needed. A homemade laser engraver powered by a battery will be sufficient.
Before making an engraver, you need to prepare the following parts for its assembly:
Remove the write head from the DVD drive.
Carefully remove the focusing lens and disassemble the head housing until you see 2 lasers hidden in heat-distributing casings.
One of them is infrared, for reading information from the disk. The second one, red, is the writing one. In order to distinguish them, apply a voltage of 3 volts to their terminals.
Pinout:
Be sure to wear dark glasses before testing. Never test the laser by looking at the diode window. You only need to look at the reflection of the beam.
You need to select the laser that lights up. You can throw away the rest if you don’t know where to use it. To protect against static, solder all leads of the diode together and set it aside. Saw off a 15 cm section from the profile. Drill a hole in it for the clock button. Make cutouts in the box for the profile, charging socket and switch.
The schematic diagram of a DIY DVD laser engraver looks like this:
Tin the contact pads on the charge control board and holder:
Using wires to pins B+ and B- of the charge controller, solder the battery compartment. Contacts + and - go to the socket, the remaining 2 go to the laser diode. First, solder the laser power supply circuit by surface mounting and insulate it well with tape.
Make sure that the terminals of the radio components do not short circuit with each other. Solder a laser diode and a button to the power supply circuit. Place the assembled device in the profile and glue the laser with heat-conducting glue. Secure the remaining parts with double-sided tape. Reinstall the tact button.
Insert the profile into the box, bring out the wires and secure it with hot glue. Solder the switch and install it. Do the same procedure with the charging socket. Using a hot glue gun, glue the battery compartment and charge controller into place. Insert the battery into the holder and close the box with the lid.
Before using it, you need to set up the laser. To do this, place a sheet of paper 10 centimeters from it, which will be a target for the laser beam. Place the focusing lens in front of the diode. By moving it further and closer, achieve a burn through the target. Glue the lens to the profile in the place where the greatest effect was achieved.
The assembled engraver is perfect for small jobs and entertainment purposes such as lighting matches and burning balloons.
Remember that the engraver is not a toy and should not be given to children. The laser beam causes irreversible consequences if it comes into contact with the eyes, so keep the device out of the reach of children.
CNC device manufacturing
For large volumes of work, a conventional engraver will not cope with the load. If you are going to use it frequently and a lot, you will need a CNC device.
Assembling the interior
You can even make a laser engraver at home. To do this, you need to remove the stepper motors and guides from the printer. They will drive the laser.
The complete list of required parts is as follows:
Connection diagram for all components:
View from above:
Explanation of symbols:
- Semiconductor laser with heatsink.
- Carriage.
- X-axis guides.
- Pressure rollers.
- Stepper motor.
- Drive gear.
- Toothed belt.
- Guide fastenings.
- Gears.
- Stepper motors.
- Sheet metal base.
- Y axis guides.
- X-axis carriages.
- Toothed belts.
- Mounting supports.
- Limit switches.
Measure the length of the guides and divide them into two groups. The first will contain 4 short ones, the second - 2 long ones. Guides from the same group must be the same length.
Add 10 centimeters to the length of each group of guides and cut the base to the resulting dimensions. Bend U-shaped supports for fastenings from scraps and weld them to the base. Mark and drill holes for the bolts.
Drill a hole in the radiator and glue the laser in there using heat-conducting glue. Solder the wires and transistor to it. Bolt the radiator to the carriage.
Install the guide rail mounts onto the two supports and secure them with bolts. Insert the Y-axis guides into the mounts, put the X-axis carriages on their free ends. Insert the remaining guides with the laser head installed on them. Place the fasteners on the Y-axis guides and screw them to the supports.
Drill holes in the places where the electric motors and gear axles are mounted. Reinstall the stepper motors and place the drive gears on their shafts. Insert pre-cut axles from a metal rod into the holes and secure them with epoxy glue. After it hardens, place the gears and pressure rollers with bearings inserted into them onto the axles.
Install the timing belts as shown in the diagram. Pull them tight before fastening. Check the mobility of the X-axis and laser head. They should move with little effort, rotating all the rollers and gears through the belts.
Connect wires to the laser, motors and end switches and tie them together with zip ties. Place the resulting bundles in movable cable channels and secure them to the carriages.
Lead the ends of the wires out.
Case manufacturing
Drill holes in the base for the corners. Step back 2 centimeters from its edges and draw a rectangle.
Its width and length repeat the dimensions of the future body. The height of the case must be such that all internal mechanisms fit into it.
Explanation of symbols:
- Loops.
- Tact button (start/stop).
- Arduino power switch.
- Laser switch.
- 2.1 x 5.5 mm socket for supplying 5 V power.
- Protective box for DC-DC inverter.
- Wires.
- Arduino protective box.
- Housing fastenings.
- Corners.
- Base.
- Legs made of non-slip material.
- Lid.
Cut out all the body parts from plywood and fasten them with corners. Using the hinges, install the cover on the body and screw it to the base. Cut a hole in the front wall and insert the wires through it.
Assemble protective covers from plywood and cut holes in them for buttons, switches and sockets. Place the Arduino in the housing so that the USB connector matches the hole provided for it. Set the DC-DC converter to a voltage of 3 V at a current of 2 A. Secure it in the housing.
Reinstall the button, power socket, switches and solder the electrical circuit of the engraver together. After soldering all the wires, install the casings on the case and screw them with self-tapping screws. For the engraver to work, you need to upload the firmware to the Arduino.
After flashing the firmware, turn on the engraver and press the “Start” button. Leave the laser turned off. Pressing the button will start the calibration process, during which the microcontroller will measure and remember the length of all axes and determine the position of the laser head. After its completion, the engraver will be completely ready for work.
Before you start working with the engraver, you need to convert the images into a format understandable for Arduino. This can be done using the Inkscape Laserengraver program. Move the selected image into it and click on Convert. Send the resulting file via cable to the Arduino and start the printing process, turning on the laser first.
Such an engraver can only process objects consisting of organic substances: wood, plastic, fabrics, paint and varnish coatings, and others. Metals, glass and ceramics cannot be engraved on it.
Never turn on the engraver with the lid open. The laser beam, entering the eyes, concentrates on the retina, damaging it. Reflexively closing your eyelids will not save you - the laser will have time to burn out an area of the retina even before they close. You may not feel anything, but over time the retina will begin to peel off, which can lead to complete or partial loss of vision.
If you catch a laser “bunny”, contact an ophthalmologist as soon as possible - this will help avoid serious problems in the future.
To make a laser engraver or CNC (computer numerical control) machine we will need:
DVD-ROM or CD-ROM
- Plywood 10 mm thick (6mm can be used)
- Wood screws 2.5 x 25 mm, 2.5 x 10 mm
- Arduino Uno (compatible boards can be used)
- Motor driver L9110S 2 pcs.
- Laser 1000 MW 405nm Blueviolet
- Analog joystick
- Button
- 5V power supply (I will use an old but working computer power supply)
- Transistor TIP120 or TIP122
- Resistor 2.2 kOhm, 0.25 W
- Connecting wires
- Electric jigsaw
- Drill
- Wood drill bits 2mm, 3mm, 4mm
- Screw 4 mm x 20 mm
- Nuts and washers 4 mm
- Soldering iron
- Solder, rosin
Step 1 Disassemble the drives.
Any CD or DVD drive is suitable for the engraver. It is necessary to disassemble it and remove the internal mechanism, they come in different sizes:
It is necessary to remove all optics and the circuit board located on the mechanism:
You need to glue a table to one of the mechanisms. You can make a table from the same plywood by cutting out a square with a side of 80 mm. Or cut the same square from the CD/DVD-ROM case. Then the part you plan to engrave can be pressed with a magnet. After cutting out the square, glue it on:
To the second mechanism you need to glue a plate to which the laser will subsequently be attached. There are a lot of manufacturing options and it depends on what you have on hand. I used a plastic model plate. In my opinion, this is the most convenient option. I got the following:
Step 2 Making the body.
To make the body of our engraver we will use 10 mm thick plywood. If you don’t have it, you can take plywood of a smaller thickness, for example 6 mm, or replace the plywood with plastic. You need to print out the following photos and use these templates to cut out one bottom part, one top part and two side parts. In the places marked with a circle, make holes for self-tapping screws with a diameter of 3 mm.
After cutting you should get the following:
In the upper and lower parts you need to make 4 mm holes for fastening your drive parts. I can’t immediately mark these holes, as they are different:
When assembling, you must use 2.5 x 25 mm wood screws. In places where screws are screwed in, it is necessary to pre-drill holes with a 2 mm drill. Otherwise the plywood may crack. If you intend to assemble the case from plastic, it is necessary to provide for connecting the parts with metal corners and use screws with a diameter of 3 mm. To give it an aesthetic appearance, our engraver should sand all the parts with fine sandpaper; if desired, they can be painted. I like black, I spray painted all the parts black.
Step 3 Prepare the power supply.
To power the engraver, you need a 5 volt power supply with a current of at least 1.5 amperes. I will use an old computer power supply. Cut off all the pads. To start the power supply, you need to short-circuit the green (PC_ON) and black (GND) wires. You can put a switch between these wires for convenience, or you can simply twist them together and use the power supply switch, if there is one.
To connect the load, we output red (+5), yellow (+12) and black (GND) wires. Purple (standby +5) can output a maximum of 2 amps or less, depending on the power supply. There is voltage on it even with the green and black wires open.
For convenience, we glue the engraver to the power supply with double-sided tape.
Step 4 Joystick for manual control.
To set the initial engraving position we will use the analog joystick and button. We place everything on the circuit board and bring out the wires to connect to the Arduino. Screw it to the body:
We connect according to the following diagram:
Out X - pin A4 Arduino Out Y - pin A5 Arduino Out Sw – pin 3 Arduino Vcc - +5 Power supply Gnd – Gnd Arduino
Step 5 Place the electrics.
We will place all the electrics behind our engraver. We fasten the Arduino Uno and the motor driver with 2.5 x 10 mm self-tapping screws. We connect as follows:
We connect the wires from the stepper motor along the X axis (table) to the outputs of the L9110S motor driver. Further like this:
B-IA – pin 7 B-IB – pin 6 A-IA – pin 5 A-IB – pin 4 Vcc - +5 from power supply GND - GND
We connect the wires from the stepper motor along the Y axis (laser) to the outputs of the L9110S motor driver. Further like this:
B-IA – pin 12 B-IB – pin 11 A-IA – pin 10 A-IB – pin 9 Vcc - +5 from power supply GND – GND
If, upon first start-up, the engines hum but do not move, it is worth swapping the screwed wires from the engines.
Don't forget to connect:
+5 from Arduino - +5 power supply GND Arduino – GND Power supply
Step 6 Install the laser.
The Internet is full of diagrams and instructions for making a laser from a laser diode from a DVD-Rom writer. This process is long and complicated. Therefore, I bought a ready-made laser with a driver and a cooling radiator. This greatly simplifies the laser engraver manufacturing process. The laser consumes up to 500 mA, so it cannot be connected directly to the Arduino. We will connect the laser through a TIP120 or TIP122 transistor.
A 2.2 kOm resistor must be included in the gap between the Base of the transistor and pin 2 of the Arduino.
Base – R 2.2 kOm – pin 2 Arduino Collector – GND Laser (black wire) Emitter – GND (Common power supply) +5 laser (red wire) - +5 power supply
There are not many connections here, so we solder everything by weight, insulate it and screw the transistor to the back of the case:
To firmly fix the laser, it is necessary to cut another plate from the same plastic as the plate glued to the Y axis. We fasten the laser cooling radiator to it with the screws included in the laser kit:
We insert the laser inside the radiator and secure it with the screws also included in the laser kit:
And we screw this whole structure onto our engraver:
Step 7 Arduino IDE programming environment.
You should download and install the Arduino IDE. The best way to do this is from the official project.
The latest version at the time of writing the instructions is ARDUINO 1.8.5. No additional libraries are required. You should connect the Arduino Uno to your computer and upload the following sketch into it:
After filling in the sketch, you should check that the engraver is working as it should.
Attention! A laser is not a toy! A laser beam, even unfocused, even reflected, damages the retina when it enters the eye. I highly recommend purchasing safety glasses! And all testing and adjustment work is carried out only in protective glasses. You should also not watch the laser during the engraving process without glasses.
Turn on the power. When the position of the joystick changes forward or backward, the table should move, and the Y axis, that is, the laser, should move left to right. When you press the button, the laser should turn on.
Next, you need to adjust the laser focus. We put on safety glasses! Place a small sheet of paper on the table and press the button. By changing the position of the lens (we rotate the lens), we find the position at which the laser point on the sheet is minimal.
Step 8 Preparing Processing.
To transfer the image to the engraver we will use the Processing programming environment. Need to download from official
The time has come when the hyperboloid of engineer Garin from the novel by Alexei Tolstoy moved to the kitchen table of an ordinary Moscow apartment.
A couple of years ago, you could find inexpensive laser engraver sets in Chinese online stores. At first, the laser power was 100 mW, then 500 mW... Recently an engraver with a power of 5 W appeared, this power of a semiconductor laser already allows not only to burn pictures on plywood, but also to cut plywood.
The laser cutter assembly kit arrived in high-quality packaging. Polystyrene foam in a cardboard box.
The laser engraver 5500mw A5 Mini Laser Engraving Machine is supplied as a kit for assembly: aluminum guides, stepper motors, control board, glasses to protect eyes from laser radiation, housing parts for assembly and control board with fittings. It took one evening to assemble the device.
The design of a laser CNC is simpler than that of a 3D printer; the same guides along which stepper motors drive the head. Only the 3D printer has three of them, and they move the head in three dimensions. In our case, it is enough for the head to simply move along a plane in two dimensions. No force is needed to move it, since there is no mechanical contact with the workpiece material. The laser engraver connects to a computer via a standard USB port.
The part you want to cut out or the image you want to burn must be drawn in a vector program. The program must save the image file in wmf format.
A file in this format can be imported into the program that controls the engraver.
It is better to use the free SketchUp program for this (a fairly simple program for creating 3D models). The BenBox program that controls the engraver is downloaded free of charge from the seller’s website.
The laser power, unfortunately, is not adjustable. The program sets the speed of movement of the head - the faster it moves, the less it burns.
If you want to cut, set the speed lower. To regulate power, you need to order an additional board; Once installed, you can adjust the power manually. For engraving, 100-500 mW is enough and for cutting material - 2000-5000 mW.
The engraver smokes slightly during operation. With the window open, the smoke didn't bother me much. But smoke delays the laser beam, reducing its power and, accordingly, the cutting depth.
Everything would be fine, but laser cutting experts write that the lens can become smoky. Therefore, immediately after purchasing a machine, you need to make a powerful exhaust hood or at least install a fan on the engraver head.
HOW A LASER CNC MACHINE CUTS
As you know, a laser does not cut, it burns. The higher the laser power, the more resistant the material it can process. The essence of laser cutting is this. that the material has time to “evaporate” in the laser beam before the edges of the material adjacent to the cutting point begin to burn.
When cutting deep, the edges of the upper layers of the material burn, so a deep cut with a laser has a trapezoidal shape with the wide side on top. When cutting material with a weak laser, the edges of the material heat up and ignite. This can be combated by blowing a thin stream of air at the cut point and multiple passes along one and the other the same trajectory.
Only here there is not a linear relationship between laser power and number of passes. That is, if you can cut through a thin sheet of balsa or plywood with a 5W laser. then to make a cut with a 2 W laser you will have to make not 2-3 passes, but much more. So it’s better to give up hopes of “buying it cheaper and just driving along the cutting lines several times.” You need to take a more powerful laser, preferably with a power reserve.
LASER FOCUSING
Laser focusing is manual.
Place the object to be engraved.
When turning on the laser at minimum power, in order to focus it on the engraved object, you must manually rotate the adjustment of the focusing lens until the size of the spot turns into a point and becomes minimal. In this case we get maximum power.
When cutting plywood, the laser beam, having cut a couple of millimeters, is already out of focus, weakens and does not cut the plywood to the end. It turns out that the deeper we cut, the weaker the beam. In this case, it makes sense to focus the laser on the surface on which the plywood piece will lie.
Practical use of the engraver at home
The engraver is ideal for cutting leather. You can apply any design to the skin and immediately cut out patterns with a laser. The big advantage of a laser when cutting synthetic fabrics and leather is that the edges are burned and then do not become shaggy. Plastic is easy to engrave. You can make the cover of your favorite smartphone stylishly engraved.
It took the author 4 months to assemble such an engraver; its power is 2 Watts. This is not too much, but it allows you to engrave on wood and plastic. The device can also cut balsa wood. The article contains all the necessary material for creating an engraver, including STL files for printing design components, as well as electronic circuits for connecting motors, lasers, and so on.
Video of the engraver at work:
Materials and tools:
Access to a 3D printer;
- stainless steel rods 5/16";
- bronze bushings (for plain bearings);
- diode M140 2 W;
- radiator and coolers to create diode cooling;
- stepper motors, pulleys, toothed belts;
- Super glue;
- wooden beam;
- plywood;
- bolts with nuts;
- acrylic (for creating inserts);
- G-2 lens and driver;
- thermal paste;
- protective glasses;
- Arduino UNO controller;
- drill, cutting tool, screws, etc.
Engraver manufacturing process:
Step one. Create the Y axis
First, you need to design the frame of the printer in Autodesk Inventor. Then you can start printing out the Y-axis elements and assembling it. The first part that is printed on a 3D printer is needed to install the stepper motor on the Y axis, connect the steel shafts and ensure sliding along one of the X axis shafts.
After the part is printed, two bronze bushings need to be installed in it; they are used as sliding supports. To reduce friction, the bushings need to be lubricated. This is an excellent solution for projects like this because it is inexpensive.
As for the guides, they are made of stainless steel rods with a diameter of 5/16". Stainless steel has a low coefficient of friction with bronze, so it is excellent for plain bearings.
A laser is also installed on the Y axis; it has a metal body and gets quite hot. To reduce the risk of overheating, you need to install an aluminum radiator and coolers for cooling. The author used old elements from a robot controller.
Among other things, in the block for the 1"X1" laser you need to make a 31/64" hole and add a bolt to the side face. The block is connected to another part, which is also printed on a 3D printer, it will move along the Y axis. To transmit movement, it is used toothed belt.
After assembling the laser module, it is installed on the Y axis. Also at this stage, stepper motors, pulleys and timing belts are installed.
Step two. Create the X axis
Wood was used to create the base of the engraver. The most important thing is that the two X axes are clearly parallel, otherwise the device will jam. To move along the X coordinate, a separate motor is used, as well as a drive belt in the center along the Y axis. Thanks to this design, the system is simple and works perfectly.
You can use superglue to attach the crossbar that connects the belt to the Y-axis. But it is best to 3D print special brackets for these purposes.
Step three. We connect and check the electronics
The homemade diode uses an M140 diode; you can buy a more powerful one, but the price will be higher. To focus the beam you will need a lens and a regulated power source. The lens is installed on the laser using thermal paste. When working with lasers, you must wear safety glasses only.
To check how the electronics work, the author turned them on outside the machine. A computer cooler is used to cool electronics. The system runs on an Arduino Uno controller, which is connected to grbl. To enable the signal to be transmitted online, Universal Gcode Sender is used. To convert vector images to G-code, you can use Inkscape with the gcodetools plugin installed. To control the laser, a contact is used that controls the operation of the spindle. This is one of the simplest examples using gcodetools.
Step four. Engraver body
The side edges are made of plywood. Since the stepper motor extends slightly beyond the body during operation, a rectangular hole must be made in the rear edge. In addition, you need to remember to make holes for cooling, power connections, and a USB port. The edges of the upper and front parts of the body are also made of plywood; acrylic walls are installed in the central part. An additional wooden platform is attached above all the elements that are installed at the bottom of the box. It is the basis for the material with which the laser works.
Orange acrylic is used to make the walls, as it absorbs laser rays well. It is important to remember that even a reflected laser beam can seriously damage the eye. That's all, the laser is ready. You can start testing.
Of course, complex images are not of very high quality, but the engraver can burn out simple ones without difficulty. It can also be used to cut balsa wood without any problems.
