3D printing has become the new fad among professionals and hobbyists alike, with new applications and possibilities arising in the science world each passing season. Printing a model as you would print a document is a fascinating prospect for many people both in and out of the manufacturing world.
For specialists within the manufacturing industry, this widespread interest in 3D printing helps draw attention to current manufacturing practices, getting more people interested in the manufacturing industry and the possibilities still on the horizon. However, what exactly does 3D printing have to offer to the manufacturing world?
3D printers are now commonplace in universities, engineering complexes and even homes across the United States. The prospect of having the means to create models and prototypes at the touch of a button is interesting to say the least. In terms of the manufacturing industry, 3D printing boasts the ability to create incredibly complex geometries that other methods are simply incapable of doing. However, this is the beginning and end of 3D printing’s current usefulness to the industry.
While 3D printing’s ability to build from the ground-up is intriguing, the industry stands to gain relatively little from 3D printing when it comes to quality and quantity production. The method certainly makes some designs possible that were previously much more difficult, if not impossible, to produce, but the cost and limitations of the equipment involved in 3D printing tend to be steep. Additionally, the relatively low surface quality of the products produced and the slow production speed of the process mean that 3D printing falls short of the effectiveness expected out of mass manufacturing processes. This is especially true when comparing 3D printing vs. CNC machining.
The more useful cousin of 3D printing, CNC machining has been part of the manufacturing world for much longer. This manufacturing process is highly effective, resulting in larger quantities of higher quality products at much faster speeds than 3D printing is capable of. This isn’t to say that CNC machining is better than 3D printing in every way, but it is certainly a more effective process at producing high-quality products at mass production quantities.
Read on to learn more about what makes CNC and 3D printing so different, the advantages and disadvantages of each and why CNC machining is still king in the manufacturing industry.
Computer numerical control machining, also known as CNC machining or milling, is a subtractive process, meaning that the process starts with more material than the product needs and cuts away, or “subtracts,” any excess material. This process works by taking a block of solid material, such as metal or wood, and using sharp cutters to remove unnecessary sections, chipping away at the material to create the final product.
Unlike other forms of machining where the machine is controlled manually, CNC machines are controlled by a highly precise computer program. The program is essentially a series of codes designed to control and direct the CNCs cutting tools to create a preprogrammed product. These codes are designed using CAM software, or computer-aided manufacturing software, usually designed by the customer or a consultant. A CAM specialist will input this software code into the CNC machine — though today a person doesn’t necessarily need special training to complete this step as the inputting process has become much simpler.
CNC manufacturing is commonly used throughout the manufacturing industry, and it’s one of the most useful processes for creating complex finished products at low costs.
CNC machining, though simple enough in concept, offers numerous impressive benefits to the manufacturing world. Some of the key benefits of CNC machining include the following:
Additionally, CNC machines tend to be easier to install and start using vs. 3D printers, primarily because of the machine’s design — CNC machines are becoming increasingly user-friendly, and the prevalence of them within the industry means that finding someone experienced in the use of the machine is rarely a problem.
At most, the product may need a little bit of tooling and surface finishing to add details and to smooth out any edges. However, the CNC machine completes most of these details during the CNC process.
Unlike 3D printers, which can produce small parts with surface anomalies due to the nature of the materials they use, CNC machines work with rigid materials that won’t deform under normal conditions, resulting in extremely high-quality small parts.
This can result in beading and other behavior that can alter the surface quality of the finished product. CNC milling gets around all of this by working with a single block of material and simply cutting away the excess. This cutting action allows the material to maintain maximum rigidity while the machine works, minimizing deformations.
As a result, a CNC machine can produce a product in a very short amount of time. They also take less time than a 3D printer because cutting away material doesn’t take as long as adding material layer by layer. CNC machines can also be used all day and all night year round if need be, provided they are regularly cleaned and maintained.
This means the material retains its strength and other key qualities in the final product. That feature is especially important for products where the strength, ductility or electrochemical properties of the final product are important.
All of these qualities mean CNC machining is much quicker and more versatile than many other manufacturing methods, especially 3D printing. Additionally, the high production speed, consistent product quality and volume-independent pricing associated with CNC machining make it an ideal method for mass producing products of a variety of sizes.
While CNC milling poses numerous advantages over other manufacturing methods, it is far from flawless. When compared to 3D printing, CNC milling does pose some minor disadvantages, including the following:
If the CNC isn’t fully enclosed, the shards and pieces can go everywhere, resulting in a mess that can interfere with the processes of other machines if not handled correctly. This excess material can sometimes be reused, as in the case of some metals, but more often than not, it is written off and disposed of as waste.
Large-diameter tools designed to quickly remove large portions of metal or wood can produce much more noise than smaller tools. The level of noise produced by the machine can greatly affect the vibrations produced by the machine, as well as the conditions within a manufacturing facility.
With the exception of design restrictions, these disadvantages have no bearing on the quality and effectiveness of the final product, which is why CNC milling is still vastly superior to 3D printing for quantity manufacturing purposes.
3D printing is a catchall term for a variety of different methods, including selective laser sintering (SLS), stereolithography (SLA) and others. The similarity between these methods, however, is that they build up products from scratch. This additive process is the polar opposite of subtractive manufacturing, involving the “addition” of material in layers, producing the final product from the ground up. This results in a vastly different product with a different set of attributes.
While this manufacturing process is particularly useful for rough prototyping and one-off products, it is not nearly as useful as CNC machining for quantity manufacturing.
3D printing is the new technological fad for a reason. It sports some incredible capabilities and functions, producing products in a novel and interesting way. Some of the key benefits of this process include the following:
Between programming the machine, setting up the machine for the product, preparing the material, setting the dimensions and deciding how to fix the material to the workstation, CNC milling takes much longer to set up than a 3D printing process by far.
These qualities make 3D printing an ideal manufacturing method for one-off products. Short lead times and the ability to create complex custom parts make this new process especially useful for constructing prototypes and small-scale models.
While the possibilities 3D printing offers are exciting, the reality is that it is a relatively ineffective process for any quantity manufacturing purposes. This is due to some of 3D printing’s limitations, including:
Additionally, 3D printers designed to handle one material usually cannot work with another — for example, a printer designed to work with thermoplastics cannot then switch to using resins, and vice versa. This greatly limits the capabilities of 3D printers and those working with them.
Thermoplastics and resins are often laid down in layers while they are still “wet”, meaning that they’ll need to solidify. Before these layers solidify, the material can bead, overflow or otherwise behave differently than expected or wanted. As a result, the surface of the final product may be very rough, requiring additional processing before it is ready for shipping.
Usually, a product that would take a CNC machine under an hour to make takes a 3D printer several. This slow speed dramatically reduces the number of products a 3D printer can feasibly make over the course of a day, making it an inefficient production method for mass-produced products.
It is true that 3D printing offers incredible opportunities and possibilities for numerous industries, especially in the cases of precision technology and prototyping. When someone needs a single highly customized part, 3D printing can do the job effectively. Many people in the 3D printing world share a vision of consumers owning their own small 3D printers in their homes, printing small, custom-made products on a daily basis to cut out the middleman.
Although this vision is an interesting take on the potential future of 3D printing, and is certainly within the realm of possibility, 3D printing is unlikely to ever replace CNC machining. Why? Because 3D printing is extremely inefficient at mass producing products. Mass-produced products created with CNC milling are much cheaper than their personally printed counterparts, and the quality and integrity of CNC milled products are vastly superior vs. those of 3D printed products.
In short, while 3D printing is an excellent method for one-off products like prototypes and extremely small-scale custom products, CNC milling is by far the best choice for manufacturing large quantities of quality products of all sizes and materials.
If you are looking for a fabrication specialist experienced in the use of CNC machines, Summit Steel can help.
Since 1992, Summit Steel & Manufacturing, Inc. has offered superior metal manufacturing and fabrication services to customers across the East Coast. We serve companies in a variety of industries, from consumer products to military and defense equipment. With our wide range of manufacturing capabilities, we can provide our customers with services of all kinds, all from a single source.
We provide only the best in service, offering you such benefits as: