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How to make CAD drawings for CNC machining

CNC machining is a term widely used in engineering and industrial manufacturing. CNC machining is a technique or process used in industry to control machines through computers to produce different machine parts. CNC stands for Computer Numerical Control. Different types of tools are controlled by CNC machines, including milling machines, lathes and grinders. A CNC machine is actually a combination of machines like lathes and milling machines, controlled by code, programmed through a computer to make different parts.

If you want a part manufactured by CNC machining a production process, there are some terms you should know.

Different technologies are used in the production process, they have certain advantages, in order to do your job accurately, you should know how these technologies work?

What is a CAD drawing?

CAD drawings are made by different software on the computer. These drawings are created in 2D and 3D. CAD stands for Computer Aided Design. CAD drawings are precisely created on the software for later use, these drawings are used for analysis and CNC machining production. There are a variety of software for creating CAD designs, almost all of which are capable of creating accurate models for CNC production.

What is G code?

As mentioned earlier, CNC machines use special coding to produce parts. This type of code commonly used by CNC machine tools is called G code. This code contains instructions for the machine to operate at a specific angle, a specified time, a repetition period, the coordinates of the tool used, and the rotational speed. CNC machines can use these CAD drawings or files to generate parts, but before converting these 3D drawings to G-code, CAM software is needed that can convert the different parameters in the drawings to G-code. CAM stands for Computer Aided Manufacturing. Now, this G-code is the computer's instructions to control the different tools to generate the required parts. This code works for a small part. Each line of code contains information about the part to be generated from the raw material block. CNC machines work in three dimensions. Now, if you need to produce parts exactly the way you want, then you have to provide 3D drawings for that.

How is the encoding done? How does it work?

CNC machines can also encode manually, but doing so can make mistakes. Since the code contains a lot of information and works with one instruction at a time, if something is misinterpreted, it can destroy the entire geometry of the part you want. For example, you have a block in which you want to create some holes, cut edges at certain angles and completely remove certain parts at certain angles. G-codes will now be generated with different combinations of numbers accordingly, which will instruct the machine to move at specific lengths and angles. If you make a small mistake along the way, and you want a set of angles on the longer side of the part to be swapped with a set of angles on the shorter side of the part, the entire geometry of the part is destroyed. To avoid such errors, 3D drawing needs to be used.

How to create 3D drawings?

3D drawings are created in software. Different 3D design software has different user interfaces and commands for generating designs. Most of the time, a 2D design of a part is created by first selecting the length and width and their dimensions, and then a 3D design is generated by extruding it to a certain thickness. Now perform different actions to make different changes in the design. Any hole pattern in a part can be made in the software and some material removed at an angle to produce the exact part you want. This part is now created by CNC machining, the CAM software is used to generate the G-code used to guide the CNC machine. There are different CAD/CAM software like Autodesk for generating 3D designs which are then converted to G-code.

Although 3D design takes some time depending on its complexity, this process can be easily handled using this technique. So in order to get what you want, you first need to generate a 3D design, make sure the 3D design is exactly what you want, and then CNC machine it to make it precise.