CNC machining or 3D printing? You'll know after seeing their differences
Choosing the right manufacturing technology will be beneficial and allow your business to move forward more smoothly, Computer Numerical Control (CNC) machining and 3D printing technologies have emerged with advances in engineering and mechanics, which of them is better? There are different factors behind the choice. The differences between 3D printing and CNC machining are now presented, breaking down and comparing each manufacturing method in order to choose the right one for a specific application.
What is CNC machining？
CNC machining or Computer Numerical Control machining is a common subtractive manufacturing technique that uses a range of sophisticated machines such as grinders, lathes, drills, routers, plasma cutters, laser cutters, and milling machines to remove redundant components from virgin materials and create shaped, precision CNC-machined parts.CNC machining covers services such as CNC milling, CNC turning, CNC drilling, and more.
CNC machining is a method of machining materials by computer-controlled machine tools. It is characterised by high precision and quality part manufacturing.
CNC machining can be applied to a variety of materials, including metals and plastics, and is suitable for producing complex parts and precision parts.
What is 3D printing？
Appearing later than CNC, 3D printing is an additive manufacturing process that typically adds material layer by layer and builds a 3D object from a computer-aided design (CAD) model.3D printing includes selective laser sintering, light-curing moulding and more.It is characterised by rapid prototyping, customisation and the realisation of complex structures.3D printing is applicable to a wide range of industries, including medical, aerospace, automotive and more.
While 3D printing has become more accessible and versatile, CNC machining services and parts still have a strong foothold in modern manufacturing and cannot be replaced by 3D printing.
Difference between 3D printing and CNC machining:
The main differences between them are material, size, speed, cost, production, scale, waste, etc.
| Comparison Dimensions | CNC Machining | 3D Printing |
| Material Types | Primarily for metal processing; can also handle plastics (ABS, Nylon, Polycarbonate, PEEK, etc.), thermoplastics, acrylic resin, cork, hardwood, modeling foam, and wax | Mainly for plastics (Nylon, PLA, ABS, ULTEM, ASA, TPU, resin, etc.); to a lesser extent for metals (aluminum, stainless steel, titanium, etc.); some technologies can use ceramics, wax, sand, and composite materials |
| Material Limitations | Materials are in conventional forms like plates, relying on blank dimensions | Can't cover all materials of traditional manufacturing; metals with high melting points are prone to deformation, and usually need a dedicated 3D printer for each material |
| Common Plastics Materials | ABS, Nylon, Polycarbonate, PEEK | Nylon, PLA, ABS, ULTEM, ASA, TPU, resin |
| Common Metals Materials | Aluminum, Stainless Steel, Titanium, Brass, Alloys | Aluminum, Stainless Steel, Titanium |
| Speed | Fast production speed; automated machines can work continuously for long periods with proper maintenance. One hour of CNC work is roughly equivalent to several hours of 3D printing | Builds layer by layer, slow speed; post - processing like cleaning, polishing, and sealing is needed after printing |
| Size | Can machine various sizes, from tiny parts to large objects (e.g., refrigerators) | Limited by the print bed; parts can't exceed the print bed size. Large components need to be split for printing |
| Waste and Cleaning | Subtractive process, generating non - recyclable waste, difficult to clean up | Uses materials as needed, precise quantity control, little waste, no complicated cleaning required |
| Quality and Precision | Smaller tolerances, high precision; good manufacturers can achieve 0.01mm precision | Relatively larger tolerances, precision lower than CNC; although industrial - grade machines can improve precision, issues like layer lines still exist |
| Versatility | Can produce tools, jigs, various custom parts; can mass - produce the same parts or one - off prototypes, suitable for a wide range of industries | Limited in terms of materials, sizes, and types; suitable for complex and special structures but has limitations in large - scale and diversified production |
Why is CNC machining superior to 3D printing?
Cost is one of the most important factors to consider when choosing a manufacturing technology, and CNC machining is often cheaper and more cost-effective than 3D printing.
Speed: as we have already said, CNC is a faster solution than 3D printing.
Difficulty: CNC machines are much easier to set up and implement than industrial 3D printers. cnc machining makes prototyping easier because the machine can carve the design out of the material and build the prototype using the exact material used to obtain the final product. But 3D printers do not create prototypes with structural strength.
Quality: CNC can create high quality and precision machined parts that 3D printers cannot match.
Product Integrity: Finished products retain the strength and other properties of the material after CNC machining, but 3D printing reduces the integrity of the part due to layering and the inability of the material to bond at a molecular level.
Volume: CNC machining is better suited for mass production than 3D printing based on speed and cost. there are some drawbacks to mass production with 3D printers that have not yet been addressed.
Differences in operating software
Most of the 3D printing slicing software is easy to operate, even a layman can be proficient in using slicing software within a day or two under professional guidance.
Because slicing software is very easy to optimise and supports automatic generation, this is why 3D printing can reach individual users.
CNC programming software is much more complex and requires a professional to operate, and people with zero foundation usually need to learn for about six months, in addition to a CNC operator to operate the CNC machine.
Differences in post-processing
There are not many options after 3D printing parts processing, generally grinding, oil spraying, deburring, dyeing and so on.
While the options after CNC lathe parts processing, in addition to grinding, oil spraying, deburring, there are plating, silkscreen, printing, metal oxidation, laser engraving, sandblasting and so on.
The above is the difference between CNC lathe machining and 3D printing, after understanding the differences between the two, which processing technology you want to choose for your parts is also very helpful!