3D Printing and CNC Machining: Basic Differences Between the Two

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3D printing and CNC machining, two closely related technologies yet differing in certain aspects about which you are going to find out in details throughout this post.

Notable differences:

3D printers in general, follow the additive manufacturing process, which is adding layers on top of another using plastic to formulate a solid object.

CNC milling machines, on the contrary, are equipped with cutters or sharp objects for getting rid of parts of a solid material (metal or wood) that aren’t required.

The technologies both require a computer in order to control them; hence computer-aided manufacturing software (CAM) such as the Autocad Fusion 360 is needed to create something unique. The files are usually in either STL or OBJ format.

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You can read more about laser engraving technology on Wikipedia.

Despite having 3D printers comprised of newer technologies with added capacity to print using different materials, the technology initiates from the ground up, layer by layer.

Suitable materials:

3D printers are capable of printing using only ABS, PLA (thermoplastics) or resins, and such thermoplastics can be combined with different materials like wood or metal.

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However, the printed objects will never be as big as the ones created using CNC mills.

CNC mills have the capacity to work on wide varieties of objects, both softwoods, and hardwoods; as a result, the use of technology will vary depending on your choice of material. You may print a prototype on the same material before a final print.

Resolution factors:

CNC mill like the Pocket NC can cut as close as 0.025 mm with a tolerance of 0.0127 mm; moreover, the materials used in a CNC mill can be extremely precise.

Inaccurate workpieces are generally caused due to buggy STL files and/or damaged cutting tools.

There are 3D printers such as the Zortrax M200 and CEL Robox capable of printing at high resolutions of 0.025mm and 0.020mm respectively; however, they still fail, but the technology is not to be blamed entirely.

The rate of work done:

3D printers require a long time to create a solid object by adding one layer after another.

CNC mills, on the other hand, do not take more than an hour for cutting away extra portions of a solid block to create an object.

Noise level:loiud-noise-forgeportal

The noise emitted from a 3D printer in action follows a rhythm, which also varies sometimes and endurable. I think it is due to the G-code embedded in an STL file.

You don’t want to stand near a CNC mill if it’s cutting off metal or wood of large diameter. The noise level can be awfully loud accompanied by intense vibration.

Waste generation:

3D printers will only use as many materials as it needs for printing an object, resulting in zero wastage (unless there are print failures).

CNC mills primarily function by cutting away portions of a solid block; thus, resulting in a lot of wastes that also become useless.

3D printing and CNC machining usage:

3D printers are not only capable of printing plastic objects but also popular for bioprinting, for constructing buildings and even vessels that have successfully traveled in space!

CNC milling is perfect if you want to create something robustly precise and/or resistant to heat.

Costs:

You will get a decent 3D printer for a minimum of $500 (Prusa Steel); whereas, a CNC mill will at least cost $2000!

Which one should you get?

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An intriguing question, but the answer lies behind the purpose of your investment. Some jobs will require a 3D printer and others will require a CNC mill; thus, depending on what you want to create.

If you’re an ambitious designer, I think it’s better to invest in both to get the best of two worlds.

In case of lack of space or resources, the better option is to get a BoXYZ, a 3D printer/CNC mill/laser cutter for $2,900.

Soon we’ll be having access to multiple options all housed under one technology, and that day isn’t far from now, the next disruptive technology.