CNC Router Development: Electronics, Firmware, and Testing

Introduction

The development of a CNC router requires the integration of mechanical, electronic, and control systems to achieve precise and automated movement. The objective of this project was to assemble and configure a small CNC machine capable of performing basic drawing and positioning tasks through numerical control. To achieve this, stepper motors were selected due to their high positioning accuracy, along with motor drivers, a control board, and a dedicated power supply. Additionally, the GRBL firmware and control software were implemented to enable communication between the computer and the machine. Once the assembly and configuration process was completed, functional tests were carried out to verify the correct operation of the CNC router and its ability to execute programmed movements.

Electronic part

For the electronics in our CNC router, it's important to know that, due to the high precision required, we must use stepper motors. Each motor needs its own controller, and we need a control board to manage all the motors and communicate with the computer. Finally, we need a power source. Therefore, we will use the following components:

With all the electronic components acquired, we proceed to wire and place all the parts where they correspond. The motor drivers have a potentiometer to limit the motor current to prevent damage. For our motors, which are the 28BYJ-48, we limit the potentiometer voltage to 0.2 V.

Control

For the control stage, it is necessary to install the software used to operate the machine. This software allows positioning of the motors and conversion of files into G-code. Additionally, the GRBL firmware must be installed so that the Arduino can control the motors. The download links for the software and Arduino code are provided here

• GRBL Controller Download
• GRBL GitHub Repository

We upload the downloaded code to the Arduino and open the control software. Then, we connect the Arduino to the computer, turn on the machine’s power supply, and the CNC plotter is ready for operation.

Finally, we carried out a simple test to verify the machine’s operation.

Conclusion

The CNC router was successfully assembled and configured by integrating the electronic components, motor control system, and GRBL software. Through the calibration and testing process, the machine demonstrated its ability to execute programmed movements accurately, validating both the hardware and software implementation. This project provided practical experience in CNC machine assembly, control, and operation, highlighting the importance of proper integration between electronics and software for achieving reliable performance.