How to prepare the drawing for CNC milling

CNC milling shapes the material by removing material from the blank. 

The term CNC indicates that the machine is programmed by computer and managed on the basis of the information contained in the file sent to the machine. 

To date, there are several models of CNC milling machines on the market, however, overall, the fundamental concepts and the preparation of the digital file to dialogue with the machine remain almost the same.

In this article we see what skills are necessary for the management and monitoring of the machine and how to prepare the file containing the information relating to the machining of the milling cutter. 

Understanding key concepts

To obtain quality milling, it is necessary to have some basic notions, so that you can manage the machine and its parameters as best as possible, depending on the material to be processed. In fact, today the CNC milling machine can be used to work different types of materials such as aluminium alloys, steel, stainless steel, plastics and soft metals.

Here's what you need to know to properly work the blank. 

• Develop a basic knowledge of the CNC machine: Familiarize yourself with the main components of the CNC machine, such as the work table, axes, actuators and spindle. Understand how the machine moves in space using the different axes and how the programming commands are executed.
• Learn the programming language: The most common programming language used for CNC machines is called G-code. The G-code is a set of instructions that define the movement of the machine, machining operations and other functions.
• Know the coordinate systems: CNC machines use a coordinate system to position the workpiece and the machine itself. Common coordinate systems include the Cartesian coordinate system (X, Y, Z) and the polar coordinate system.

Preparation of program files

To communicate with the machine's computer, it is necessary to send a digital file containing all the information related to the processing. Therefore, the preparation of digital drawing requires highly specialised modelling skills. 

For this reason, here is a brief guide for preparing the digital file for CNC milling.

• Create a CAD drawing or model: Use computer-aided design (CAD) software to create a technical drawing or 3D model of the part you want to produce. Make sure the model contains all the necessary dimensions and specifications.
• Convert the drawing to a CAM file: Use computer-aided manufacturing (CAM) software to convert the CAD drawing or model to a CAM file. This file will contain the necessary information about the workpiece geometry, machining operations and toolpaths.
• Generate the G-code: Using the CAM software, generate the G-code based on the CAM file. Be sure to select the correct cutting tool, machining parameters (such as feed rate and cutting depth), and movement axes required for your workpiece.

Conclusions

Although CNC milling is an automated process, the preparation of the machine requires specific skills. For this reason, the operator must be aware of the fundamental concepts for the preparation of the machine, the necessary parameters to be set and the preparation of the digital file in order to be able to send the correct information to the machine.

Sometimes it is possible that the operator, despite knowing the fundamental concepts, does not have knowledge of digital modelling. In this case, it is possible to rely on expert technical designers and request the creation of the drawing in order to ensure the correct performance of the processing.

Did you know that ErreBiLab offers the CNC milling and turning service? We can provide you with highly specialised technical designers and operators. Contact us and we will find the best solution to implement your project.