The manufacture of laser engraver

Today I'll share with you a project finished a while ago: a low-cost laser engraving machine. Due to the low cost and parts that are easy to get, you can quickly make a copy.

Be careful: there is a 250 MV laser in this project, and the laser beam does great harm to our eyes, so please don’t look into the laser beam.

Tools and materials needed: Banana Pro, two scrap CD drivers, two drive circuits of Stepper motor, a 250 Mv laser head, a drive circuit of laser. Following the principle of more easy to get, laser driver circuit and stepper motor drive circuits are done with the same kind of module - L298N.

Manufacturing process

1. Disassemble CD drivers

Process that disassembling CD drivers will not be showed in detail, the reason we break the CD drivers is we just want to reuse the stepper motor and slider, so please, don’t break them.

2. Machine case

In order to make the appearance of this engraving machine more beautiful, we will be making a wooden shell by laser cutting machine in the laboratory, and installing the stepper motors, one is responsible for the X axis, the other one is for the Y axis.

Click here to download the CAD drawing of the wooden box:

3. Install the circuit

The circuit is made of one Banana Pro, three driving modules and a laser.

One of the L298N modules is used to drive the laser. In order to prevent excessive current, I connected an adjustable resistor in the middle. The other two L298N modules are used to drive the two step motors.

4. Wiring

When wiring, pay attention to 4 I/O ports of Banana Pro for the control of 4 wire stepper motor. For example: the above stepper motor is controlled by NO.36, 37, 38, 39 I/O ports, the following stepper motor is controlled by NO.26, 27, 28, 29 I/O ports. The laser also needs one I/O port of Banana Pro to be controlled. Here we select NO.11 I/O port. Besides we propose to separate the power supply of Banana Pro and other drive modules.

5 Install the software

You need to install two parts of the program: install the Inkscape software and the Laser EngraverExtension plug-in on your PC, and install Python’s GPIO libraries and carving packages. Inkscape can be downloaded on the Internet. The download address of Laser Engraver Extension plug-in:

Install Inkscape according to the installation instructions.

Then extract the Laser Engraver Extension,place the extracted files to the Inkscape installation directory /extensions, restart Inkscape, and there will be an extra plug-in in Inkscape. So you can generate G code with the Inkscape.

In the Banana Pro，you need to download the Python code controlling stepper motors.

Download address:

Assuming that the path of code which has been extracted is /home/bananapi/laser_engraver, then copy the G code to the file. Assuming that the name of the G code file is test.nc, run ./engraver.py test.nc in the terminal.

Note: Before the first time you run the code, you need to test the origin of the stepper motor’s position, and adjust the focus of laser.