Which Processes Fit to Your Project:CNC Machining or 3D Printing
3D printing, known as additive manufacturing is expected as the industrial process to produce the parts which are impossible made by conventional process CNC machining process. However 3D printing is not fit to all the part production with its technical limitations. This article we will discuss where are the limits of the manufacturing technologies and what are the differences between the two processes?
Precision and functionality of the 3D printer
The computer-generated item is constructed layer by layer using 3D printing. The 3D print head can be moved in each of the three spatial directions, in contrast to a standard inkjet printer. A process known as additive manufacturing is 3D printing. Unlike cnc machining, 3D printing additive material layer by layer. Almost any thing may be made with a 3D printer, whether it has hollow parts, curves, unique structures, or shapes with undercuts.
The only constructions that additionally require a so-called support material in order to be printed are overhanging and overhanging constructions. After the component is finished, the support element is only separated.
A wide range of variables affect the obtainable accuracy. A few of the impacting elements include feed speed, nozzle temperature, heating plate temperature, guide accuracy and squareness, and feed rate. Up to 0.05 mm layer thicknesses and resolutions are possible with industrial level equipment. In 3D printing, the individual layers are typically easily apparent.
Materials for 3D printing
Of course, liquid or powdered ingredients should be used for all 3D printing materials. The plastic or metal can then be injected into the heating extruder nozzle. Wood cannot theoretically be printed. On the other hand, thermoplastics are fantastically deformable. ABS, PLA, and Nylon are the plastics that are most frequently used in inexpensive printers. Not all devices can process all contents, it should be stated. Only highly expensive, specialised machines in the industry, which are especially specialised in metal printing, can also print metals like titanium or aluminium.
Software for 3D printing
It is possible to prepare a 3D model for printing using straightforward applications. The training takes minimal time and requires little effort. Traditional CAD software is much more difficult to use and can occasionally remain challenging even after the initial instruction. Because of this, it's probably worthwhile to consider purchasing a 3D printer.
Do 3D printed things have any geometry restrictions?
Everything that is currently visible on the market is produced. The 3D printer may be used to create a variety of things, from smartphone cases to artificial joints. To ensure a revolution in this area, developers are even moving forwards at full speed on artificial cell tissue.
The subtractive CNC machining
When using a CNC machining machine, block material that has undergone subtractive manufacturing processing is required in advance. Here, the material is progressively withdrawn in contrast to a 3D printer. A CNC programme that must have all the data beforehand controls the CNC machining machine as well. Additionally, the subtractive method enables the machining of hardened metals, wood, and even polymers. The CNC machining machine must still be used to make all non-liquefiable materials.
For instance, the 3D printer is undoubtedly a better option for cavities and undercuts than the 3-axis CNC machining machine. On the other hand, engravings are more affordable when done on a CNC machining machine as opposed to a printer, which uses additive material application. Additionally, the machining machine is to be prefered if the material needs to have a very high tensile strength and a high E-modulus, which is what metals typically have (unless you have a metal printer). Additionally, 3D printer accuracy is still insufficient to produce precisely fitted surfaces.
Another consideration in the debate between a 3D printer and a CNC machining centre is the CNC machining center's ability, for instance, to cut threads.
3D printing or CNC machining? Pros and cons of the procedures
Advantages of 3D printer
- Objects can be quickly printed layer by layer
- Numerous materials that liquefy are applicable
- Getting started with the software is easier
- Cavities, complex structures and undercuts are possible
Disadvantages of 3D printer
- Engraving is cumbersome
- Does not work with all materials. e.g. wood
- The accuracy and dimensional accuracy that can be achieved tend to be worse than with CNC machining
- Often not suitable for structures that require high strength
Advantages of CNC machining
- Ideal for wood, plastics and metals
- Ideal for high-strength constructions and functional assemblies
- Engravings can be implemented quickly
- Manufacturing of fits and threads possible
Disadvantages of CNC machining
- Waste or material consumption due to the principle of removal
- Cavities cannot be created
- CNC programming (path planning, tool change, path optimization) is much more demanding
It undoubtedly be surprised by 3D printing and witness some market developments. However, it is unlikely that CNC machining will disappear entirely anytime soon. Both techniques will be allowed to continue in the future, with the 3D printer still having more promise than the CNC machining centre.
Whether it's a 3D printer or CNC machining machine - I wish you every success in your next project. Do you have questions about 3D printing or CNC machining? Then just contact our Exzellenc cnc team who will give you more details about your project.