So you want to know more about how to make a CNC machine?

Whether it is a 3D printer or a mil of some sort, this will take you through the basics a give you a nice idea of how they work, operate and what parts you will need or can choose from.

Fist of I have built my own CNC router with a pretty good result, and currently working on a combined printer, router and laser cutter.

What is this CNC stuff anyway? CNC stands for Computer Numerical(ly) Controlled in short, it works with your computer 1s and 0s to signal your motors to start and stop and stop, run and reverse when you want it. If you like to know more about that
I suggest you hit it up on the net, there are tons of nice explanations there.

and the next steps will take you through the different main parts of the machine, and what you need to know about them, to make the most of them, as understanding them will help you to a long lasting machine.

The basics of a CNC router, lathe or 3D printer is pretty much the same, the bigest differance is how they operate and is controlled, the router and lathe remove material from what they are working with to achive their goal, and the 3D printer adds it but the main parts will be the same no mater what system you want to build.

the guide will be made up of different parts, focusing on different aspects of the build. And guideing you all the way to make your own wonder! Also please comment my work (in any constructive way), and ask as many questions as you like! This way I can improve the guide as I work.

Thank you

Step 1: The basics first

What does a CNC machine consist of?

For the main
electrical parts it will consist of

  • Computer
  • Breakout board
  • Motors
  • Power supply unit (PSU)
  • Limit switches

In simple terms

The computer will run your program send the programs signal to the breakout board, the board will turn those signals into a new signal that will run the motors. The PSU is there to power your motors and or breakout board limit switches, and

all the other nice stuff you can mount on the machine. The limit switches are not a requirement, but they are nice to have, since your machine will then know when and where to stop, before it runs in to itself, which may damage the machine.

The main mechanical
parts are:

  • Frame
    Guides (and their supports)

The frame of the machine is pretty obvious, it holds all the other components in place, and also gives the machine the stiffness it will need to work on objects, the transmission is to transfer movement of the motors to your axis, this will be covered a bit later.

the bearings keeps the spindles where it should be, and if you use the right bearing type, they will even help reduce strain on the spindles.

Couplers are the actual coupling between motor and spindle.

The guides are for guiding your linear movement and keep your machine steady while it works.

So now you should know what a basic CNC machine is made of, what happens when we put it all together?

Depending on the machine will most commonly have 3-4 axis to worry about, an X-, Y,- Z-, and C-axis

It works just like a coordinate system where you have X to the forward and backwards motion, Y to the left, and right motion, Z is for the ups and downs, and if you have the fourth axis it will control the rotations of your working object, as seen in the first picture.

This is pretty much the basics of the CNC machine itself, they may vary a bit from machine to machine, but all this will be cover a bit later.

Basic operation of the computer.

So how does the computer know where to go, and what signals does it send? This is a bit more complicated, but in short you will need a program that can interpret drawings and generate the code needed. There are different programs capable of doing this, but what you need to be looking for is something that can generate a G-code or an M-code, this is either done in your drawing program or a program known as a Computer Aided Manufacturing program (CAM) the code is then transferred to your control software, where it can be used to run from there.

Types of machines
There are generally two main types of CNC machines the ones where the work surface is moveable and one where the gantry is moveable


Alright that was the very basics of the CNC Machine. To sum it all up here are the main thing to remember

The computer runs the breakout board, and the board controls the motors, that are coupled to the spindles, where we have our guides, bearings and the stuff we would like to move.

<p>Really nice explaining, this is exactly what I needed, the big view of the CNC, thanks a lot, I can understand all of the other posts now, I was so confused before reading your topic... You nailed it..</p><p>Hope to see ( part-2) soon, and hear about your hybrid CNC that you are working on it.</p>
<p>I'm really glad it was of use to you!</p><p>If you have any questions, or if there is anything you think I missed or should explain better please let me know.</p>
<p>Wow that is what i really wanted. Nice way of explaining each part. <br>Can you please upload 2D drawings with dimensions. I want to know the exact size of each component.<br>THANKS in advance and Good Luck :D</p>
<p>A bit depending your skills and equipment and money I do know of better designs that looks like this however they are a bit more expensive</p><p>Also my drawings contain a few undocumented things as my challenge was to design and build my own, so I had to do a bit of prototyping here and there.</p><p>Anyhow you can have the full 3D drawings if you like, since I&rsquo;m working on a brand new design, when school is not in the way&hellip; which they are quite a lot at the time.</p>

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Bio: Currently studying as an engineer. I have a great flair for mechanical and automatic stuff. Currently I'm working a CNC router and a tutorial ... More »
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