How to Operate CNC Milling Machine (The Starter’s Guide)

How to Operate CNC Milling MachineMilling custom parts and cutting metals are not a very difficult task once you own a working CNC machine. You are free to build almost anything with this amazing tool. Moving on from your earlier pet projects, a CNC acquisition finally gets you into some bigger deals.

But before that dream works out, there’s one thing you need to get sorted from. It’s about operating CNC milling machine. And you obviously have guessed from the title, we are about to do that!

How to Operate CNC Milling Machine:

Getting the Basics, Operations, Learning & More…

There’s still a long way to go before you actually start using the CNC machine. And so, you need to have patience and a strong will to learn as a beginner from the very beginning. Make sure you don’t rush over things and end up questioning everything. It’s going to need some time to adapt to the machine’s operation. But I’m sure you can do it.

To make it as simple as possible, I’ll be discussing the overall CNC mechanism to learning tips. By the end of today’s chat, I hope many of you would feel confident about using such an outstanding milling machine.

So, Let’s Go For It!

General Idea About CNC Machine.

Now let me start with how this brilliant mechanism works in manufacturing. The information on every operation’s feature is given to machine through input. This is basically data about the dimensions and tooling location of a particular raw component or material.

This, of course, needs the operator’s skill. It is given through formal training and know-how.

During the first cycle of operation, complete observation is necessary to make sure there’s no tool breakage. So that any damage to the milling machine or expensive material can never happen.

The components of a CNC machine are described shortly below.

  • The heart of a CNC machine is basically its control panel. This is a part where a technician inserts the G-code. The code is actually containing commands of operation through requirements. Through a computer keyboard, this information goes in.
  • The machine and metal both become quite hot while milling. There’s a special mechanism in the CNC machine that keeps both of these cool. It’s called coolant supply tubes and coolant material. The first part is necessary for pumping and later one keeps metal cool. For smooth movement, this component keeps lubricating cutting tool as well.
  • Whatever material you’ll be working on sits over a surface for milling. This work area in CNC machine is known as the table. There are also clamps available for keeping material in place.
  • Axis is another part of a CNC machine that can be one or many in different versions. Usually, there are up to six axes available in a CNC milling machine.
  • The part that holds milling potion along moving with axis is known as a column.
  • Finally, there’s a cutting tool, which as its name describes does the actual job. This part is usually linking with the column.

CNC Milling Operations

There is a wide range of versatility available with a CNC machine. And for that reason, you can try it for various industries where designs, slots, pockets, threads, and chamfer inclusion are necessary. Common operations that help here are the next thing we’ll focus on.

Form Milling

When you need to mill surfaces that are irregular, this operation works greatly. Form milling is suitable for outlining and contouring as well. You can easily mill materials that have flat or curved surfaces. There is a special part called fly cutters that are phenomenal at it. For example, there are convex, concave and corner rounding cutters.

Producing bead hemispherical are some common examples of form milling applications. It is also popularly used for intricate design and single machine set up needs.

Face Milling

Talking about face milling, this operation is pretty simple actually. The workpiece’s surface stays perpendicular to the rotating axis of cutting tool. Here the teeth stay on tool face as well as periphery. The face teeth are in charge of finishing application. However, the peripheral teeth help in cutting.

This milling technique helps in piece contouring. Also, it helps to make flat surfaces. The process is better at higher quality finish production as well. The method is suitable for both horizontal and vertical milling.

End and side milling are two very popular examples here. There are end and side milling cutters available to do the operation.

Angular Milling

The cutting tool’s axis of rotation stays within an angle relative to workpiece’s surface. This is the angular milling operation basically. It’s also known as angle milling to some experts.

Using single-angle milling cutters, this application is possible. The particular design’s angle is valid here. It’s super common for applications such as grooves, serration and chamfer making. The milling technique helps to create better angular features.

Making dovetails is a very common example of angular milling. It needs a specific dovetail cutter that can be working at 60, 55, 50 or 45 degrees. It actually depends on what dovetail design you want to go for.

Plain Milling

Slab or surface milling is two other names for this common milling operation. It actually refers to the operation where cutting tool’s axis of rotation stays parallelly with material’s surface. There are plain milling cutters available for this operation.

The cutter usually comes with teeth on periphery. Depending on different design specification you complete the milling application. Here the cutting depth, workpiece size, and some other factors come into use. These factors decide whether you need a wide or narrow cutter.

For deeper cuts, one needs to go with a narrow cutter. On the other hand, if you are working with huge surface areas, then using a wide cutter is a better option.

The operation sometimes requires removing a huge amount of material from workpiece. In such cases, coarse-toothed cutters are severally used. With fast feed rates and slower cutting speed, the right specification following designable parts are possible to create.

Next, with a finer tooth cutter, you need to work for details in finishing parts. Here faster-cutting speed and slow feed rate is applicable.

Gang Milling

A milling operation that needs more than two cutters falls under this category. The cutters here are usually of different width, shape, and size. All of these happen with similar machine arbor.

For dealing with intricate designs and confusing parts producing in a short time, this method is preferable. Here cutters are capable to perform different or similar cutting operations.

Straddle Milling

A straddle milling operation works with a single cut. However here the tool deals with more than two parallel workpiece surfaces. In the same machine arbor, more than two cutters are used to perform straddle milling operation.

The cutters stay on either side of workpiece. This arrangement helps to mill both sides at the very same time.

Gear Cutting

Gear cutters are used for this specific milling operation. Here gear teeth come into play for application. These are basically a formed milling cutter type.

You can find them in different pitch sizes and shapes. It depends on what gear design you are working for and how many teeth are necessary. Specialized lathe cutter bit is also sometimes usable for this process.

Profile Milling

This is a very usable type of milling operation that works great for both vertical and angled surfaces of workpieces. It cuts along the path and needs a profile milling equipment. The cutting tool can be either perpendicular or parallel with material’s surface.

How to Learn CNC Milling Machine Operations?

So now you have a pretty good idea about the operations available with the CNC milling machine. You are all ready to go for some cutting.

However, don’t immediately jump to it, instead start with practicing. Use some materials that are not too expensive. You can try on stainless steel metals later, but avoid it for now. Try working on wood, brass, plastic and aluminum workpieces at first.

Starting with softer materials, you can gradually go for mild steel. Once the cuts seem mastered, you can try tough materials.

Mastering means no attacking looks at the material, smoother finish and not breaking cutters. That’s when you can call yourself good enough to proceed.

Slowly and gradually the milling operation will start making sense to you. Just keep on practicing the operations that you took an idea of and see how things change interestingly.


There’s way more to do for learning CNC milling. But you’ve managed to learn some basic things that will help to get you started with operating. I hope my guide on how to operate CNC milling machine with several operations was interesting to you.

Now move ahead and learn to design, generating G-codes with CAD/CAM software and you’ll be partially skilled. Reaching proficiency levels one by one is the smartest way, and everyone would agree. There will be always more to learn and you need to figure those out.

Till Then Keep Practicing and Learning! Good Luck!

About James

Hi! I’m James. I’m the main author of it’s been my passion to deal with power tools. This website is mainly to talk about various power source tools. I want to explore tackles and help people to pick the right model for their daily needs. Follow me: Facebook, Twitter