Build Your Own CNC Machine

Updated Jun 13, 2022
The Ox - Open Source CNC Machine

CNC machines have been around for decades, with their history stretching back to the 1950s. In that time, they’ve transformed the way we manufacture things. They’ve also helped to democratize the process, providing a way for budding engineers and makers around the world to create their own products. With such versatility on offer, you—yes, you!—might be wondering how to build your own CNC machine.

If this sounds like you, never fear—the team at Scan2CAD is here to help. We’re here to provide handy tips on building a CNC machine. We’ll include some great options for CNC kits, as well as details and resources covering how to build your own CNC machine from scratch. Let’s get started!

What to Look out For (Frequently Asked Questions)

So, you’re about to build your own CNC machine. But where do you start?

Before comparing kits or choosing components, it’s important to start answering some fundamental questions.

1. What are you going to make with your CNC machine?

Of course, CNC machines are versatile, and allow you to create a wide range of different products. However, different types of CNC machine are better for different projects.

Start by considering the types of projects you’re likely to take on, and use this as a basis for the type of CNC machine you choose. This decision will also inform the components you need to produce your machine.

2. How much time does it take to build a custom CNC machine from scratch?

Building a custom CNC machine from scratch is a difficult undertaking. The difficulty emanates from the fact that the machine needs to be accurate, sturdy, and capable of performing even the most difficult cutting tasks. What’s more, the pulley system that facilitates movements along the x, y, and z axes should not in any way impact the accuracy of the cuts. It should also be sturdy enough to support the router’s weight and facilitate movement along the z-axis.

Taking all these factors into consideration, therefore, requires planning and a well-thought-out design. This means the build-out phase actually begins when you set out to design the CNC machine and ends when you finally put the components together. Building a custom CNC machine from scratch can therefore take anywhere between a few weeks and several months.

The exact duration is dependent on various factors. For instance, if you intend to create a consumer-grade CNC machine for personal use, it should take you less than a month – around four weeks (this time includes the design period). On the other hand, if you intend to build an industrial-grade CNC machine that weighs more than three tons, you should expect to spend more than six months. Generally, the duration is dependent on the factors listed below.

  • Size and weight of the parts and materials: heavy materials and parts such as the motor would ordinarily require you to work with lifting equipment, and this could take up more time than if the parts were liftable using human power
  • Origin of the components, i.e., whether locally available or imported. The duration is condensed if all the parts and materials are easily accessible locally. But if they are imported, and considering the ongoing disruptions that are affecting supply chains, it would take much longer
  • Availability of the parts: if the parts are readily available, then you will not have to wait for prolonged periods in order to get ahold of them
  • Craftsmanship: if you are highly skilled at milling, welding, and assembling the various parts, then it should not take you a considerable time to put the parts together.

3. How much time does it take to assemble a ready-made CNC machine?

If you do not have the capacity to build a custom CNC machine, do not fret. You can purchase a ready-made CNC kit/machine and build (assemble) it. The manufacturers of these CNC kits/machines ship them in a disassembled state, with the various parts already cut or machined. Thus, as the buyer, you do not have to use milling or cutting equipment. Rather, all you need to do is to follow the instructions included in the package, which should guide you on how to go about everything.

It should take you between one and three hours to complete building a ready-made consumer-grade CNC machine, depending on how versed your skillset is.

4. How much are you looking to spend on your CNC machine?

Your answer here will partly arise from whether you intend to use the machine for professional or personal use. In both scenarios, however, it’s always worth trying to get the most for your money. As such, you should evaluate which parts and components are necessary for the machine you want to build. If you don’t need them, don’t buy them! Set yourself a budget you know you can afford, and stick to it. (We have explored the cost in great detail below).

5. What skill sets should you have to build a CNC machine?

It’s easier to build your own CNC machine if you already have some of the necessary skills. As such, aim to complete a project that plays to your experience.

If you’re already experienced in woodworking or metalworking, then you may wish to try out a more challenging project. A newcomer, meanwhile, may wish to start out with something simpler. In fact, CNC Cookbook recommends that, if this is your first build, that you start with a simpler machine. This way, you’ll be more likely to get it done, rather than biting off more than you can chew and giving up.

CNC kits

A CNC kit is an incredibly convenient way to build your own CNC machine. That’s because a kit generally comes complete with everything you need to put your machine together and get started with making things.

Most kit manufacturers will also offer a number of customization options. This allows you to choose the right components to suit your needs. You can opt for the most basic package if you’re on a tight budget—or splurge if you have more specific requirements.

Thankfully, here at Scan2CAD, we’ve already put together a list of some great CNC kits for beginners. Featured on the list are:

  • MillRight CNC — though basic, this comes in as one of the cheapest CNC kits on the market. A great option if you’re looking to build your own CNC machine for the first time.
  • Shapeoko — this machine arrives partially assembled, making it one of the easiest projects to complete. If you’re feeling more ambitious, Shapeoko is also hackable, giving you real freedom to modify the machine.
  • Maslow — affordable CNC—bigger. Maslow offers users a massive 4’x8′ workspace, letting you create large projects easily.
  • Next 3D — don’t want to get your hands dirty? The Next 3D offers users the chance to build a CNC machine without soldering, drilling or gluing. Simply screw together and get going in no time.

Looking for more detail? Check out our full list of the best CNC kits for beginners.

Build your own CNC machine from scratch

Using a CNC kit is one of the easiest ways to get up and running, but it’s not for everyone. If you’d rather have the freedom to build your CNC machine your way, then building from scratch can be a great option.

What you’ll need

As you may have already guessed, there are a vast array of possibilities when it comes to building a CNC machine. However, your CNC machine will likely include most, if not all, of the following parts:

  • Electrical parts, including:
    • Processor/control board (some machines may use a PC)
    • Stepper shield
    • Stepper drivers
    • Motors
    • Power supply
  • Mechanical parts, including:
    • Tools, such as cutting tools
    • A frame
    • Bearings
    • Guides and supports
    • Spacers, washers, nuts, screws, and bolts

Of course, figuring out which type of CNC machine to build will help to clarify which parts you’ll need. If you’re struggling to come to a decision, check out our comparison of CNC machines to find out which one’s right for you.

How to build your own CNC machine from scratch

The exact assembly of your CNC machine will depend on the type of machine you choose to build, the custom options you choose, what you plan on making with the machine, and many other factors. Nevertheless, the key steps to build your own CNC machine will generally be as follows:

1. Design your machine

CNC machine in CAD

Creating a design for your CNC machine will help give you a clear idea on the finished project. You may choose to start out with a sketch, before converting the paper drawing to CAD using programs such as Scan2CAD. From there, you can extrude your 2D drawing into a 3D CAD model in programs such as SolidWorks (or one of our top affordable SolidWorks alternatives).

2. Get the parts

Once you’ve designed your machine, you can then proceed to buying the parts for it. Use the list above as a guideline, but feel free to customize the machine to meet your requirements!

3. Construct the frame

Your frame is what holds together all the other parts of your machine. As such, it’s the first construction you’ll perform when you build your own CNC machine. Metals such as aluminum are good choices for your frame, as they will ensure stability and rigidity. This will, in turn, help increase the lifespan of your other hardware.

4. Add the gantry

CAD model of gantry

Not all CNC machines will feature a gantry, but as one of the most popular design options, we’ve featured it here. A gantry allows your machining tool to move along the Y-axis; it will hold your tool in place above the workspace. Ensure to balance forces acting on your gantry to reduce the potential of machine deformation or shaking.

5. Bring in the Z-axis…

Your tool itself will be moving up and down along the Z-axis. You will, however, need a place to house your tool. You’ll mount this housing to the gantry, giving your tool a greater range of depth.

6. …then the X-axis

Adding bearings and guide rails will help to maintain the rigidity of your CNC machine, and will enable your tool to move forwards and backwards along the X-axis.

7. Drive it!

Now that you’ve added the parts that will allow your CNC to move forwards and backwards, it’s time to add those that will actually make it move on this axis. This is the drive system, typically made up of motors, pulleys, spindles, screws, bolts and nuts, amongst other parts.

8. Introduce the electronic parts

Motor cross section

You’re now ready to add the many electronic parts that will make up the heart of your CNC machine. Key to this is the motor that will, ultimately, drive the machining tool. In this case, you’ll have a choice of stepper and servo motors. However, this is far from the only important tool: you’ll also need to include a PSU, breakout board, drivers, and—of course—a processor or computer.

9. Put the table top on

You can’t machine parts without having a place to put them! Your cutting table can be made of plywood, MDF or metal. Bear in mind, however, that not all of these materials will be suitable for the type of CNC machine you’re creating!

10. From rotational to linear movement

The motor you’ve installed will cause the machine to spin. However, your CNC machine will typically require linear motion. A spindle converts the rotational motion of the motor to linear motion, meaning that your machining tool will be able to move up and down.

11. Choose your controller

A CNC controller is vital to the operation of a CNC machine. This is the part that interprets the signals given by your processor or computer, and transforms them into signals for the electronic parts of your CNC machine. As such, it acts as the “brain” of the entire system.

12. Select your software

Your machine is now almost operational! First, however, you’ll need to choose the software that controls your CNC machine. Most of these will use languages such as G-code to control the movement of your machine along its three axes, enabling you to perform the action of machining.

13. Add your machining tool

CNC drill bits

There are a wide variety of machining tools available. Metal cutting tools are one of the simpler varieties, but more elaborate machines may use laser or plasma cutting tools.

14. Start making things!

Your machine is now complete, and you’re ready to start tackling your own projects!

Why build your own CNC machine?

If you’ve read this entire article, then chances are that you’re already sold on the benefits of building a CNC machine. However, if you’re still unsure, we’ll quickly run through some of the best reasons to build your own CNC machine:

1. Customizability 

When you buy a CNC machine, it may lack features you need—or make you pay extra for features you don’t. If you build your own CNC machine, you have the ability to choose what (not) to include.

2. Save money

Purchasing a ready-made CNC machine can often set you back thousands of dollars. Building your own CNC machine instead can give you the same results for a much lower cost. To put this into perspective, here is a breakdown of the various costs you will likely incur as well as the savings.

A consumer-grade/hobbyist-grade CNC machine costs between $1,000 and $3,000. On the other hand, to purchase a professional CNC router, you have to shell out anywhere between $5,000 and $100,000. An entry-level 3-axis vertical machining center (mill) costs $60,000-$100,000, while production or industrial-grade CNC machines will set you back $150,000-$300,000.

If you opt to create a CNC machine from scratch, however, you are likely to spend less than $1,000 for the parts required to build a hobbyist-grade CNC machine or a professional CNC router. The savings on your end will likely originate from the materials used, the CNC software (there are several free, open-source software available), and the cost of the spindle motor (which ranges between $100 and $300 for a two hp 24,000 RPM spindle motor). It is noteworthy that ready-made CNC machines use spindle motors with these specifications, yet the machines cost upwards of $10,000. A good example is the Tormach 24r base machine, which currently costs $14,995).

On the other hand, if you opt to build a custom industrial-grade CNC machine, you are likely to spend anywhere between $15,000 and $30,000. This custom builder, for example, had a budget of $15,000. Their custom CNC machine includes multiple advanced features such as a cage, weight covers on all axes, and an automatic tool changer. Due to inflation, however, the total cost should be several notches above this figure, which is why our estimates have a wide wiggle room. Regardless, this amount is less than the $60,000-$300,000 you would have to spend to buy a top-of-the-line entry-level or production vertical milling machine.

3. Create awesome things

Okay, so this applies to any CNC machine, regardless of whether you buy or build. But it remains true—building a CNC machine gives you the ability to manufacture your own amazing products. Whether you want to launch your own business, replace hard-to-find parts, or simply create custom products that aren’t available anywhere else, you can do it with a CNC machine. And where better to start as a maker than in building your own machine?

Still need a little more inspiration before taking the plunge? It’s right here: weekly packages of free DXF files from Scan2CAD—plus our guide to even more sites with free DXF designs.

Final Thoughts

If you are looking to build a CNC machine, you can opt to create a custom one from scratch or purchase a CNC kit. The former approach takes much longer than the latter and requires you to possess advanced skills. Nonetheless, it is much more rewarding as it is cheaper and allows for customization.

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