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What is the best CNC control software?
You have to familiarize yourself with a CNC control software for your machine once you’ve mastered CAD and CAM software in order to design your parts and prepare your G-code for milling.
There are a lot of different software; while some are free or open source, others are linked to a specific control board. Since it might be hard to make a decision, you can find our comparison of the most used CNC control software and the reason why we have decided to implement PlanetCNC on Mekanika’s CNC milling machine.
Before talking about drawbacks and benefits of each software, we need to comprehend how a CNC milling machine is controlled. The electronics that control a CNC are basically formed of like this:
- Each axis is controlled by one or two motors ;
- Each motor gets its instructions from a driver ;
- A central breakout board transfers instructions to the different drivers, depending on the information it gets from a control software;
- A control software – directly connected to the controller with a transfer protocol (usually USB or Parallel DB25). Unlike industrial CNC machines, the control software is generally running on an external device like a computer.

The above diagram is a simple representation of the control system of Mekanika CNC milling machine.
Things that you need to consider while choosing a control software is:
- The intuitiveness of the user interface;
- The hardware you’re using: type of controller + type of device running the software;
- The transfer protocol;
- The documentation coming with the software + the community activity + the frequency of updates;
PlanetCNC
Let’s start with the best on the market so far: PlanetCNC.

PlanetCNC associate with its own hardware, which have developed a single-board USB controller. This allows up to four axes and manufacture everything in Slovenia, Europe.
They offer many nice features out-of-the-box, such as automatic tool length measure or tool change and thus, support all compensation methods for common milling operations, as well as 3D milling. Moreover, the software runs on Windows, Linux or Mac. This is compatible to almost all CAM programs on the market. It can also import a wide range of files like Gerber, PLT/HPGL, DXF or NC files.
Why we have chosen PlanetCNC :
- When designing the Mekanika CNC machine, several controllers and software were tested. As a result, PlanetCNC came on top in terms of software stability and robustness of electronic components. What is more, it suits perfectly on a Raspberry Pi 4. This has allowed us to make a standalone electronic enclosure without needing any external computer for use.
- PlanetCNC has the interface which is the easiest to use, which allows a quick taking in hands. It also allows maximum flexibility by having a handy G-code manipulation window. Moreover, the user interface is also customizable.
- All the required features that a CNC milling machine needs are provided, without any redundant options (unnecessary options make the use of the machine more complicated).
- The transfer protocol is very practical; with USB.
- The software provides an API. This enables to create applications on top of it.
- Some custom features are very easy to use, such as spindle control, video display or relay control.
Mach3
Let’s continue with Mach3 which is the most popular software on the market so far.

Mach3 is a control software which is compatible with many hardware solutions and has positioned itself as the market leader for low-end CNC control software. Its success is mainly historical because it appeared at a time when its interface was more user-friendly than what existed on the market so far.
Pros:
- An easy-to-use User Interface even though the design is old-style
- The interface itself is highly adjustable to customize it to your needs
- Lots of documentation is available online through its community of users as 70% of hobby CNC users use Mach3
- Some custom features (spindle control, video display or relay control) are very practical
Cons:
- Mach3 uses a parallel-port transfer protocol. That is not compatible with most computers today
Note: Artsoft developed Mach4, which they claim to have begun from scratch and have solved almost all gaps of Mach3. However, they struggled to make their community switch from Mach3 to Mach4.
LinuxCNC
A free open source Linux software, which is created in 1993, is the ancestor of all low-end CNC software. Most further control software – like Mach3 – have relied their original code on the LinuxCNC project.

The project is favored from a wide variety of community that has developed several versions of the software and has granted to the fact that it is the second most used CNC control software today.
Pros:
- As many people have used this software, it provides a huge flexibility. However, it might be confusing for some beginners in CNC milling or for the ones looking for a compact software without unnecessary options
- The community of LinuxCNC provide a lot of good facilities to newcomers to help them solve issues
- The features and possibilities of LinuxCNC are almost infinite, but the learning curve is vital as well
Cons:
- The software may seem mind-boggling at first
- As a real-time application, it runs on parallel transfer and thus does not support a USB-parallel adapter. This makes it difficult to use on modern computers
- User interface is little bit confusing to adjust it to your needs
GRBL + USG
GRBL is – technically speaking – a CNC control software. However, it does not appear with a user interface. It is an open source software; it means that it allows microcontrollers like Arduino to receive G-code from a computer, through USB transfer.
It is generally integrated with a G-code sender software. This allows the user to transfer G-code to the Arduino. One software has been navigating through the multitude of available software: the Universal G-code Sender.

Pros:
- Arduino is a recognized microcontroller and it’s practical for DIYers to build a homemade CNC with the GRBL system;
- It’s the most handy setup for small machines and first-time home made CNC’s;
- Software is free of charge and hardware is inexpensive;
- You can choose your favorite software to generate G-code.
Cons:
- Arduino cannot deal with huge works and complex milling actions;
- This setup can easily become the blockage of your system.
Flashcut
Flashcut CNC is a Windows-based American software developed as an integrated CAD, CAM and CNC control solution, which runs with its own integrated hardware.

Even though FlashCut is the sixth most used CNC control software with less than 2% of market shares, it still is a reference for the robustness of its solution and is more preferred by professional users.
Pros :
- It comes with its own stable hardware
- The transfer protocol FlashCut CNC uses USB.
Cons :
- It is only compatible with Windows, so impossible to develop a standalone system based on a Raspberry Pi.
- Compared to PlanetCNC, the solution is more expensive than hobbyist solutions. But its reason is acceptable.
Conclusions
The best software to use will always be based on your needs and your knowledge about CNC milling.
- If you’re building your own machine, then carefully pick software based on the hardware, whichyou are going to use.
- If you’re buying a machine, check the compatibility of this machine with the softwareyou are going to use.
- If you want endless flexibility and are familiar with a huge learning curve, go for LinuxCNC.
- If you want good flexibility but do not worry too much about user experience, then choose Mach3. Also, consider your hardware and computer compatibility with parallel transfer.
- If you want to concentrate on stability and use experience to focus on your work, then prefer PlanetCNC.
Very good !