CNC Router and Custom CNC Controller

My name is Josef Pecka and I am studying 3rd year at Brno University of Technology. During my studies at the university, I started to work on my biggest project so far, a complete design of a CNC router including the control system.

CNC Router

This project started at the end of 2022 as an idea to build a frame for a laser module but soon turned into a CNC machine with the possibility of mounting a laser or a spindle. The aim of the project was to create a device with a robust enough structure to be able to machine wood, plastics, and also softer metals such as aluminum. It would be made using available 3D printing technologies to manufacture most of the parts and reduce its costs. In the following six months, the design was constructed and the first version was built. Subsequently, the design was modified in several iterations, mainly to increase the machining accuracy and the rigidity of the whole CNC machine. By the end of summer 2023, the current version was built, containing among other things, an 800W spindle controlled by a VFD, linear rails and ballscrews.

The current version of my CNC router

CNC Controller

Since the beginning of the whole project, a cheap controller and stepper motor driver have been used to control the CNC. Due to the simplicity of the controller, it was not sufficient in terms of control requirements and also its minimal protection against EMC interference could cause malfunction and damage to the workpiece or even the CNC machine itself. Based on the low reliability of the control system, as part of my bachelor thesis, I have designed an improved control system that incorporates modern stepper motor drivers, 12V digital inputs/outputs and 0-10V analog output for the spindle speed control. As its heart, a 32-bit microprocessor is used which allows the use of more modern control software. The design also aims to minimize interference and increase reliability by using galvanic isolation of individual parts to avoid ground loops and to protect the operator and computer that controls the CNC.

Custom CNC Controller - 3D view

Custom CNC Controller - TOP view

Possible improvements

Due to some crucial parts still being made from 3D printed plastic, the overall rigidity is far from perfect, especially in the Z axis which slightly deforms under stress and thus reduces machine accuracy and limits the milling capabilities.

Sponsorship from PCBWay would greatly help the project to improve with its wide capabilities of additive and subtractive manufacturing capabilities some important structural parts could be made from more durable plastics or even metal which would make a crucial contribution to the machine. The sponsorship would also help to speed up the development of the CNC controller by utilizing the PCB services that PCBWay provides.