What products can be made with CNC machines?
The short answer is that CNC machines can make almost anything. Whether you want a delicate blade or a cleanly machined block, a CNC machine can make it. All you need is a 3D CAD file from which the work instructions can be made.
One point in favor of CNC machining services is that they can process almost any material. CNC machines can handle plastic, most metals and natural materials like wood. CNC machining is cost-competitive with injection molding until you’re dealing with incredibly high production rates or massive items best made with blow molding. There are even CNC machines that can cut stone.
If the item fits inside the CNC machine’s envelope and is made from a material it can handle, the CNC machine can make it. It doesn’t matter if you’re making a unique item or a mass produced one.
CNC machines offer far tighter tolerances than most manufacturing methods. For example, CNC machines often have tolerances ten times tighter than 3D printers, and they are much more accurate than traditional machining methods. This is why CNC machines are the first choice for medical and aerospace products.
What can’t be made by CNC machining?
CNC machining services generally cannot process ceramics. The material is too hard. CNC machines can’t work with cloth, but they can handle foam. The foam models may be used to create injection molds or serve as conceptual models.
CNC machines cannot make mostly hollow structures, and you can’t create a hollow hole in the material without drilling, cutting or some other processing step. That’s only possible with 3D printing. However, CNC machines may come with lasers that can bore straight holes into the material or cut through deep grooves into the piece.
CNC machines cannot create curved shapes. For example, they can’t make cylinders or spheres. However, you could perform a number of machining operations on something in a CNC machine after it has come off a milling machine that turned a rectangular block of material into a cylinder.
CNC machines may not be able to eliminate the need for fixtures and attachments in complex designs. This means CNC machines are not always the best choice for complex shapes and ultra-light parts.
CNC machines can’t apply extreme pressure to the end part. This is why CNC machine shops may have sheet metal machines in the back. The CNC machine could make every custom piece inside the electrical enclosure except the wiring and the sheet metal housing that protects the entire assembly.
What are the benefits of CNC machining?
CNC machining is far faster than 3D printing. CNC machines can handle much larger and heavier blocks of material, as well. For example, CNC machining services can often make plastic structures ten times the size of what could come off a desktop 3D printer.
CNC machines can be programmed to create the same design again and again. CNC machining operations may have robotic arms that take the piece out of the CNC machine and send it on to finish operations. Furthermore, there are CNC machining operations with multiple CNC machines, so they can make several items simultaneously. This may not be traditional mass production, but it may result in hundreds of parts produced each day.
This means the assembly line needs only one machine tender for four or five machines, feeding in material and handling error messages. This results in lower manufacturing costs for unique items and small production runs.
CNC machines can quickly switch between programs and materials, though the tooling may need to be swapped out. This minimizes downtime on the production line and allows you to create multiple unique items from the same CNC machine.
CNC machines can quickly and accurately cut a piece in several dimensions. Put the blank or casting in the CNC machine, and a 3 or 5 axis CNC machine could turn it in multiple directions as it is worked. By having nearly all the work done on a single machine, you minimize the number of times the item has to be moved and how many places it must be worked on. This reduces the opportunity for defects and damage to the item, improving overall quality.