Free CNC software comparison

Before choosing your software, it helps to understand the two jobs involved. CAM software creates the G-code from your drawing or model. Controller software reads that G-code and runs the machine. You’ll usually need both.

Software	What it does	Operating system	Machine or controller compatibility	Cost and main limitations
OpenBuilds CONTROL	Sends G-code, jogs the machine and helps with setup	Windows, macOS, Linux	Compatible Grbl and grblHAL controllers, including OpenBuilds BlackBox	Free. Mainly for running the machine. Use separate CAM software to create your toolpaths.
ioSender	Sends G-code, with probing, jogging and configuration tools	Windows	Grbl and grblHAL controllers	Free and open source. Windows only.
Universal Gcode Sender (UGS)	Sends G-code and controls the machine	Windows, macOS, Linux	Grbl, FluidNC, TinyG, g2core and Smoothieware	Free and open source. Check the features supported by your particular controller.
cncjs	Controls the machine through a browser interface	Runs on Windows, macOS, Linux or Raspberry Pi	Grbl, Grbl-Mega, Smoothieware, TinyG and g2core	Free and open source. The browser connects to cncjs running on a computer. It is not simply an online CAM service.
LinuxCNC	Runs the machine using a configured motion-control interface	Linux	Suitable parallel-port hardware or supported interfaces such as Mesa cards	Free and open source. Requires a suitable Linux computer and more configuration than a typical USB Grbl setup.
GRBL HotWire	Runs a four-axis hot-wire foam cutter	Windows	Supported Mega2560, grblHAL and FluidNC foam-cutter configurations	Free to download. Needs compatible four-axis firmware and separate software to generate wing or fuselage G-code.
OpenBuilds CAM	Generates G-code from drawings and images	Compatible web browser	Routing, laser, plasma and drag-knife workflows	Free. Useful for drawing-based jobs. It is not a dedicated four-axis foam-wing generator.
Autodesk Fusion for personal use	CAD design and CAM toolpath generation	Windows, macOS	Exports G-code through a suitable post-processor for your machine	Free for qualifying personal, non-commercial use. Limited CAM features. Four- and five-axis milling are not included.
Mach3 (paid alternative)	Runs the machine through a compatible motion-control interface	Windows	Parallel-port setups or supported external motion controllers	Paid software with a restricted demo. The milling demo runs up to 500 lines of G-code.

Why would I use free CNC software?

You’ve built your 4 Axis hot wire foam cutting machine or 3 Axis router and now you need CNC control software. I often get questions through this website from fellow hobbyist asking what software they can use to cut foam wings, fuselages or parts on their CNC router. Most hobbyists are prepared to pay a reasonable price but when you start adding up the cost of the machine as well it soon adds up to a chunk of cash.

This article is an overview of what’s available to the hobbyists and then the follow-up articles will go into more detail for each solution. It’s not an exhaustive list and I’ve picked out solutions which I think are suitable.

I haven’t included anything about Laser Engraving software because as yet I have no expereince of it.

Example costs for paid CNC software

If you were to buy Mach3 or a Mach4 license at $175/$200 and the software I use for foam cutting DevWing Foam 2 €125 and DevFus Foam €95, then you’re up to $400/€340/£300. I’ve always had good support from DevCad who supplies the Foam software. So are there any free or low-cost?

There’s an old saying that you get what you pay for, and with CNC software that is sometimes true but surprisingly some of the free software is very good. You will find that the paid options tend to be more comprehensive.

4 Axis for Foam Cutting

I’ve created separate posts for these so please check

What Controller Software can I use for CNC Foam Cutters? – rcKeith

G-code generation software for CNC foam cutter – rcKeith

3 Axis for CNC Router and Mills

For CNC routers there are quite a few free options Your choice does depend on the hardware used. Most hobbyists now use USB-based or Wifi controllers running grbl, grblHAL or FluidNC. There are several free options available. The list isn’t exhaustive but these are the ones I’ve used or heard good reports about

• OpenBuild Control
• SenderIO
• UGS (Universal Gcode Sender)
• CNCjs
• Mach3/4
• LinuxCNC

OpenBuilds Control

This is good software and works with most grbl-based controllers. I’ve used it on my CNC Router with great success with a needle cutter attachment and to cut many plywood parts for RC aeroplanes. I’m currently using an MKS Tinybee 32-bit controller running grblHAL. More specific details are here

SenderIO

This is now my preferred software for grblHAL controllers. It works well but the only downside is it is Windows only. Download it from here

UGS

I haven’t used UGS but it is widely used and will run on most operating systems as it’s Java-based.

CNCjs

Again I haven’t used CNCjs but it is widely used and will run on most operating systems because it uses Node.js

Mach3

I started with Mach3 many years ago and it’s capable software. But I wouldn’t recommend it now if you are new to CNC. Mach3 is quite old now and has been superseded by Mach4. I have a full post here on Mach3 explaining how to use it with newer computers. Mach3 is $175

LinuxCNC

This is free software and does require some effort to get working. You’ll need a dedicated computer running with the old parallel port or a special interface card. The details are here on using LinuxCNC for CNC routers.

Some of my best projects were made using LinuxCNC but I had an IT background and a few old computers so several years ago it made sense to use it. But I wouldn’t recommend it now for guys new to CNC. It’s fantastic software and is still being developed but it’s a steep learning curve.

Benefits of Using Free CNC Software

One benefit of using free/open source software apart from the obvious cost saving is the community. If you get stuck there is usually a wealth of knowledge and people willing to help. You may even be talking with the developers so you gain a better understanding of your system.

G-code Software for 3-Axis Router

OpenBuild CAM

This is a web application that can integrate with OpenBuilds Control. If you have that running it will transfer the g-code directly. Or you save the g-code. I have used it with my CNC Needle Cutter and it works fine. It’s quite easy to use but I have found DXF files with splines don’t import very well. It will only work with polylines.

Being web-based it will work on any computer with a compatible browser. Check the website for detail

Fusion 360

This is now my preferred option but it does take some time and effort to learn. I’ve used this for my latest F18 and have several more projects planned that will use it.

This is a powerful program that comes from the makers of AutoCAD and runs on Windows and Mac. Get it from this link https://www.autodesk.com/products/fusion-360/free-trial and there is an option for the hobbyist. I’ve used it for making motor mounts on my OX CNC router and a spinner for my Focke Wulf 190. I was able to export the STL file into the slicing software Cura which I then used my 3d printer to produce, check out the video.

Conclusion

As you can see there are solutions for both 3 and 4-axis machines. Which one you use depends on how complex your projects are. For 3-axis routers Fusion, 360 will do all you need plus a lot more, but it’s a steep learning curve. It is well worth the effort. I use it for all my router and 3D printing projects. For foam cutting, the paid options are more polished and perhaps a little easier to learn but if you are prepared to put in the time to learn the software then you may have all you need.