What type of files are used in CNC machinery?

Machinery based on computer numerical control (CNC) technology is commonplace across the manufacturing industry. And while it may seem like a cutting edge alternative to more traditional methods of processing materials, it has actually been around for decades.

There is even a growing array of equipment in this segment which is compact and affordable enough for home use, and even smaller workshops and producers can take advantage of what CNC has to offer.

One common question newcomers have about CNC gear is what type of files are required to instruct the machinery. Can you just fire over any old plans in whatever format you have to hand, or do you need something more specific? Let’s answer those questions and explore this variety of equipment in a little more detail to clear up any confusion.

the laser cuts sparks production
the laser cuts sparks production

Getting to Know G Code

The foundation of most CNC machinery is something known as G Code, with the G in this case standing for ‘geometric’.  This is the code which provides the equipment with instructions on how to manipulate its tooling and other mechanical components in order to deliver the desired end result, dictating both the speed and direction of movement.

This means that in order to interact with CNC machinery, your original design needs to be converted into G Code which can then be interpreted appropriately.

Exploring CAD File Options

The next challenge is to work out which file types will play nice with G Code-capable equipment. The good news is that these types of programs also work with older CNC machines, so getting old machinery to complete a brand new computer-aided design (CAD) file is no problem.

One of the most widely used CAD file types for creating objects with CNC machinery is STEP, which is also known as the Standard for the Exchange of Product Data. It is capable of displaying three-dimensional models and is both broadly compatible with CAD and computer-aided manufacturing (CAM) software solutions.

Another older yet still surprisingly widespread format in this context is IGES, or the Initial Graphics Exchange Specification. It is a little less efficient than STEP, but that does not stop lots of organizations and designers from sticking with it.

STEP and IGES are typically preferable for converting CAD files to G Code that a CNC machine can work with, since while there are other file formats, these tend to be proprietary and thus only compatible with hardware and software from a given vendor.

Considering Conversion Capabilities

The final thing to consider is how CAD conversion is handled for the purposes of CAM and CNC compatibility.

As mentioned already, lots of modern CAD software will give you the ability to automatically convert your designs so that they are ready to be put into production by all sorts of CNC gear.

There are also online tools which make this a possibility, which is particularly appropriate if you are a home-brew hobbyist rather than a business owner with a lot of budget for premium software packages.

Whichever route you take, do your research first so you can ensure that your software and machinery are cross-compatible.

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