So which is better CNC vs 3d printing? There are a number of manufacturing processes for turning raw material into either the finished product or a part of a finished product. Chief among these are CNC (Computer Numerical Control) and the new ‘upstart’ 3D Printing.
There are many different types of CNC and 3D printing and you can discover more about CNC here. Therefore in the CNC vs 3d printing debate, we will look at both processes as a general whole.
CNC has existed for a number of decades and has matured to the point of being the go-to process for manufacturing parts. 3D printing, however, is relatively new, it’s seen as a fad, but to say that would be a huge disservice to the process.
CNC manufacturing and 3D printing are basically the opposite of each other; CNC is a subtractive method, whereas 3D printing is additive. Perhaps the simplest comparison is to see 3D printing as making a statue out of clay, and CNC as making a statue from marble. They might not be siblings, but the processes are certainly cousins.
Here we discuss CNC vs 3d printing, in particular, we are discussing industrial 3D printing, rather than consumer 3D printing machines.
What is 3D Printing?
3D printing is a generalized term for a number of different manufacturing methods. This includes; Selective Laser Sintering, Stereolithography, and others. The one similarity of all these methods is that they build up the product or part from scratch, layer by layer. This then results in products with a vastly different set of attributes.
As a process, 3D printing is especially useful for rough prototyping or when the ‘print run’ is in very small numbers and also needs to be done in-house. This means that as a manufacturing process it is not as useful or as viable as CNC machining for quality or quantity.
These are the answers in the debate on CNC vs 3d printing.
CNC vs 3d printing – the advantages of CNC Machining
CNC machining is a fairly simple concept which offers many advantages to manufacturers in almost every field of industry.
The CNC machining process has the ability to be applied to a vast range of products and materials. It requires little adjustment, in most cases only the cutting tool to be used may need changing between projects. In short, CNC machining can produce a product in large quantities in a very short amount of time. 3D printing is so time-consuming that even the fastest industrial 3D printing machines will take hours to produce a single part.
CNC machines are becoming far easier to install and start using vs industrial 3D printers. The CNC machines are user-friendly and the prevalence of them means finding an experienced operator is rarely a problem. Whereas there is a dearth of operators of industrial 3D printing machines.
CNC machining is a one-shot process. The process is extremely precise and the accuracy of CNC machines means that the product which leaves the machine needs minimal to no further tooling before the product is shipped out to the customer.
The incredible surface finish eliminates unplanned burrs and edges. The most the part may require is some surface finishing and smoothing out, all of which is carried out in the CNC machining process.
3D printing, on the other hand, will require lengthy and complex finishing to bring the product to near useable tolerances. Even then the finishing and accuracy will never match a product produced on a CNC machine.
Relatively high speed
When the finished product leaving the CNC machine is taken into account, there is nothing close to the speed of a CNC machine. This accuracy and speed allied with the absence of human operator errors mean that the product is produced at amazing speeds. This speed combined with the accuracy means that CNC is suited to everything from small, medium to large production runs.
Combined with the ability of a well-maintained machine to run for hours on end, day and night, year-round, means that there is only one winner; CNC machining.
3D printing, on the other hand, is a very slow process, adding material will always take longer than subtracting it. A part produced on a 3D printer can take several hours whereas, on a CNC machine, the same part would take less than an hour.
CNC machining uses a subtractive production method, and because of this method, the material is not heated or reformed, the molecular bonds in the material are not altered by heat or the introduction of any other materials. This means that the finished product retains the materials strength and other properties.
In 3D printing, the process, though able to produce complex parts, reduces the integrity of the parts because it is layering material, and this means that the final product cannot be structurally sound as the materials cannot bond at the molecular level.
A good CNC machine can offer accuracy down to an incredible 0.001 inch. This is regardless of the material being used. The rigidity of materials such as steel and aluminum means that they will not deform and thus be able to be machined into highly accurate small parts.
3D printing, in theory at least, is able to be accurate down to near CNC machines but in practice, due in no small part to the materials used, 3D printing cannot match anywhere near the accuracy of CNC machines. This alone is why the question of CNC vs 3d printing makes CNC machining the outright winner.
A CNC machine is capable of producing tools, fixture and a vast range of custom-designed parts. Whether you need to produce hundreds of the same part or a one-off prototype, CNC machines are capable of doing it. Even prototyping, a mainstay of 3D printing, can be much faster to produce on a CNC machine.
3D printing is also limited in terms of the materials it can use, CNC, on the other hand, is capable of using a massive range of materials.
- Metal alloys
- Modeling foam
- Machining wax
Price and Volume
3D printing costs depend on the volume of needed materials. Final product volume doesn’t dictate the price for CNC machines. 3D printing wouldn’t be cost-effective with larger orders, and this is the situation where CNC machines thrive.
All of these qualities of CNC machining means that in the debate of CNC vs 3d printing, it is CNC machining which is the preferred manufacturing process for almost every industry.
There is no doubt amongst manufacturers that CNC machining is a far better process for manufacturing then 3D printing, certainly for the foreseeable future.
At Wisconsin Metal Tech, we are ISO 9001 Certified specialists in CNC machining, we offer a number of CNC services in Swiss Machining, Verticle and Horizontal Milling, Shaft Turning and Gun Drilling. Contact us today to discuss your requirements.