There are instances where we have been asked to CNC machine parts, product or perhaps a prototype which can be either tough to machine, too complicated geometrically, won’t yield great accuracy or simply just cannot be machined. What do we all do? For these scenarios, 3D printing the various components can be a great solution. So why not substitute CNC machining with 3D printing each and every time? Well, you will discover advantages and disadvantages, advantages and disadvantages for each machine and process. So, which is best for our needs? In which circumstances should we prefer one above the other? And is there another solution which may combine these together to generate a combo part?
The basic difference between the 2 processes is the fact that with CNC machining were reducing material even as start with a foam block as an example, carving it away; while with 3D printing we’re layering on and adding material until we get the final product, therefore called additive manufacturing.
The 3D printer uses a similar materials define the part it can be creating, by way of example ABS PLA and nylon, but it really cannot switch between materials, whereas in CNC machining we are able to use several kinds of materials, often adding additional materials right at the end. However, machining is usually messy – Sometimes we must use a dust collector while operating a CNC router machine capture all that excess created in the drilling, carving and milling process, you will find less waste produces in printing as well as the whole process is silent.
CNC machining could be more precise providing more accuracy considering that the machines have a very higher tolerance for heat. It can also create a much smoother polished surface finish in the materials being machined. 3D printers may actually distort an element, bend and warp if using an excessive amount heat within the layered material, therefore exceptional smoothness becomes necessary the 3D printing will flunk.
3D printing is mostly an easier far easier process and never as labor-intense as CNC machining, since with machining we should program, write a G-Code, setup different tools and speed, select cutting path and tidy up after. However, the part size plays a part, as larger parts take longer being printed adding layer by layer. Overall, 3D printing will help in some cases of prototyping of high geometric complexity the spot that the router tool cannot reach in the shape.
3D printers is only able to use the section of the printer bed itself to fabricate the various components. Therefore, if large parts are expected they might struggle to fit in there. It is also not advised for mass production because materials are a lot easier more expensive and take considerably more time to make. Therefore, 3D printing is a bit more appropriate and even more cost-effective for low volume production.
CNC machining can rarely run unattended and needs skilled operator, while with 3D printing we could easily run the task unsupervised plus it requires minimal practicing for its operator. However, CNC machining is definitely an older practice (got going in the 40’s) and currently is still equipped with a stronger position inside the manufacturing industry. 3D printing is pretty new but still evolving to become more useful and adaptable and still are not a full option to machining.
In summary, the favorite choices technique to use is going to be determined by the information, geometric complexity, manufacturing volume and our budget. As a general guidance, we may switch to 3D printing mostly if fast turn-around in critical, if your part is way too complex to get machined, for prototyping small volumes and when we could do with certain materials that is not easily machined.
Having named most of the positives and negatives for each technique, apparently there exists a good solution that combines the 2 together to generate one part. We often machine regions of the desired product having a CNC router, while fabricating other small yet more complicated parts inside the 3D printer, you have to glue every aspect together to produce one unit. Another option is to coat all glued combined parts with hard coat like Polyurea, Styrospray or epoxy, then smooth and paint them. That way the two of us save time while using CNC machining process in addition to being able to manufacture more difficult parts combining the best of the 2 worlds together to produce a hybrid.