In short, CNC machines are versatile and reliable methods of manufacturing that can work with a range of materials. However, this doesn’t tell you much about how they work, how much they cost, which CNC machines are the best, and the different types of machines. It’s a lot to research at the same time.
Whether you are looking to buy a CNC machine or if you’re just browsing the internet, we’ve got you covered. Here is the ultimate guide to CNC machines!
What are CNC machines?
There is an abundance of CNC machines used by manufacturers and industrial settings, including 3D printers, lathes, drills, grinders, and mills.
CNC machines (Computer Numerically Controlled machines) are electrical-mechanical devices that control and manipulate tools and materials through computer programming. The computer program controls and manipulates such tools through high-precision around a 5 or 3.5 on the axes.
We all know the X, Y, and Z axes are the main conventional cartesian axes, but most CNC machines also work with the A, B, and C axes. These refer to the rotations around the cartesian axes.
In Layman’s terms, CNC machines are computer systems that can change and create tools and materials. The computer system works cooperatively with the machine and manufacturing directives, which then helps to turn the computerized creation into a physical reality.
CNC machines were built in the 1940s and developed further in the 50s, with the aim to make the manufacturing process more efficient.
Around this time (after the Second World War), CNC machines were used for creating stiffened skins for improving aircraft. These machines have since advanced and developed further every decade, to the point where anyone can now buy one.
What does CNC machines stand for?
CNC machines stand for Computer Numerically Controlled Machines. As the name suggests, this name refers to the computer programming system that sends numerical coordinates to the machine function, which then turns the coordinates into a physical reality.
This computer system controls the way the machine moves, which therefore determines how the physical product will look.
The way the computer program and machine communicate is through a language called G-code. This language is what sends the information of the axes directions from the computer program directly to the machine. It also communicates other information such as the speed of the spindles.
How CNC machines work:
The easiest way to explain how CNC machines work is to imagine a robot. The brain of the robot is a computer program that translates and sends information to the machine, which then creates whatever the program desires. Not so dissimilar from how the human brain works!
A computer program is pre-programmed software that gives specific and detailed instructions to the machine to create an object or tool. This is achieved through the G Code language.
The detailed instructions range from the speed and size of the spindles to the specific shape that needs to be created from the material.
The reason CNC machines are so popular is because of their reliability. Sure, humans can also be reliable workers, but these machines are designed to create the exact same product or tool over and over again. This exactitude is something only a robotic machine can do.
Humans do very little when it comes to how CNC machines create the desired object or product. Of course, there’s a lot of work behind programming the machines, but they generally do everything for you as the software is mostly pre-programmed.
The way these machines create objects is that they cut away at blocks of material (such as metal or wood), rather than create new material. It’s kind of like the ultimate metal/wood-carving technology.
The spindle is a rotating taper that holds different tools depending on what the manufacturer is making, which then moves along various axes to carve into the material block.
How to program CNC machines:
For the most part, humans do very little when it comes to programming CNC machines. Once the program has been set into the software, the machine does the rest for you. This is the nature of mechanical programming, as it works to minimize what humans need to do.
A CNC operator will have to feed the specific program of instructions into the computer and adjust the necessary tools depending on the machine and the product it is making. Once the program has been fed to the computer system, the machine completes the rest of the work.
As you can imagine, creating the specified instructions on the program can be a complicated task due to how precise the instructions must be. The machine copies the instructions exactly, so any mistake will be produced in the final product or object.
That mistake will then also be repeated on other models of the same product if it hasn’t been amended.
The program is translated to the machine through a language called G-code. It is called this because most of the words and parts of the code start with the letter G. However, the G-code will vary from different machines and manufacturers.
The G-code will tell the machine what axes to run along, the speed of the spindle, which tools to use, what feed rates, and more. The machine will read these codes like a book as the instructions are set on separate lines, which helps it to differentiate the steps. It will then follow these instructions exactly.
General steps to programming a CNC machine are:
- Start the program
- Load the chosen tool in the spindle
- Turn the spindle on
- Turn on the coolant (which helps to prevent overheating and melting)
- Move the spindle to the right position above the material
- Start the machine process until the product or object is complete
- Turn off the coolant and then the spindle
- Move away from the machine
- End the program
Of course, each program will have its own set of instructions and steps to complete the object, tool, or product, but this is the general idea of how much human involvement there is with CNC machines.
How to calculate machining cost for CNC machines:
The general machining cost for CNC machines is the total cost of the materials used, the hours of labor, and the hourly price rate. The more complex the product structure is, the more money it will cost to make it.
Other factors including the size of the structure and how curved it is will also increase the cost.
The type of material will affect the machining cost as some CNC machines aren’t designed to handle materials such as stainless steel. The entire machine will need to have specific hardy tools and computer gongs from other international machines (usually Japanese gongs), which will increase the price.
This is mostly because complex structures will require complex programs, which take much more time to create to prevent mistakes.
The reason why machining costs for CNC machines can be so high is because of the product quality, reliability, service, and delivery time.
Customers will be able to ask for an estimated price when convening with a CNC machine operator, who will calculate the total cost once they have an idea of what program to use, what tools they need, and other specifications.
Whilst there are ways to lower the machining cost, you will be sacrificing your money for products that aren’t of high quality.
Clients on a budget will often ask for the operator to use lower-quality materials or to use a high speed on the machine to fasten the process. However, you can’t rush the process for reliable products and objects!
Who makes the best CNC machines?
Whilst most CNC machines are reliable pieces of equipment, you should make sure to research specific manufacturers to get an idea of their reviews, price ranges, quality, and service.
Here are some of the manufacturers who make the best CNC machines:
Mazak has been one of the most popular manufacturing names in industrial settings for almost a century. This company began as a Japanese machine tool maker, which then expanded to the global production of machines. Mazak prides itself on its high-quality and advanced products that retain their value for years.
Haas is the largest and most popular machine tool builder in the West, holding a gold standard of CNC lathes. Their specific machinery expertise in lathes is what makes them a common machine in workshops.
Doosan is a Korean production company that has secured a place in the top position of the global market. Their CNC machines are particularly durable and of high quality, and their lathes come with a variety of features for enhanced functionality.
Liechti is possibly the best company for CNC machines with multiple spindles, making it a popular choice for aircraft and aerospace.
Tormach is a reliable CNC machine company for those on a budget. Their machines and work are used by entrepreneurs, hobbyists, and workshops.
How much are CNC machines?
Due to the reliability, functionality, and usefulness of CNC machines, these things don’t come cheap. They truly are an investment that can be used for many years at a time, and their versatility and possibilities are what make them a worthwhile investment.
As you can expect, different CNC machines will come with different price points. It all depends on the manufacturer, the machine model, and the type of machine which will have different capabilities and capacities.
Though an operator or manufacturer would be able to give a more accurate estimate as to how much CNC machines cost.
General prices to CNC Machines:
- Lathe machine: between $10,000 and $430,000
- Hobbyist CNC router: between $1,000 and $3,000
- Professional CNC router: between $5,000 and $100,000
- Entry-level 3 axis vertical machining center: between $60,000 and $100,000
- Professional 3 axis vertical machining center: between $150,000 and $300,000
- Entry-level 5 axis Mill: between $200,000 and $500,000
- Professional production 5 axis Mill: over $500,000
Keep in mind that these are rough estimates because some manufacturers and operators will be open for negotiations. Take a look at an article we wrote on the 5 best inexpensive CNC machines.
Factors that could change the estimated figure of a machine:
- Size of the machine and number of axes (the bigger the machine and the higher the axis configuration, the more expensive it will be)
- Weight of the machine (rigid, heavy frames are more expensive but durable)
- Power (spindle torque)
- Speed (RPM and tool change times)
- Country of the manufacturer
- Additional options (coolant, part loader, automatic tool changer, bar feeder, etc.)
What types of CNC machines are there?
The development of CNC machines over the decades has resulted in different machines for different purposes. Here are the most common CNC machines:
3D printers are possibly the most popular form of CNC machines, but they are fairly different from the majority of CNC machines. Most CNC machines subtract from a chunk of material to create a product, whereas 3D printers create material through layers. The same system is used with G-codes and programming.
Lathes are most commonly used in workshops that deal with making tools, carving wood and metal, and creating intricate pieces of jewelry like rings. The most basic models work with 2 axes, and lathes are usually used for making symmetrical and cylindrical objects.
Routers are mostly used for cutting larger dimensions on materials such as metal, wood, plastics, and sheets. They can have anywhere between 3 to 6 axis coordinates, making them ideal for large and complex products and objects.
Milling machines use handwheels and lead screws to move the cutting tools, which provides highly accurate, intricate pieces of work.
CNC machines are highly useful and reliable pieces of machinery that can create an abundance of tools, products, and objects with minimal human supervision. These robotic machines rely on an intricate computer program that sends instructions to the machine to create the desired object.
Whilst they are expensive and take a lot of work to program at first, they are a worthwhile investment for companies, workshops, and hobbyists alike.