CNC milling is one of the manufacturing processes of CNC machining. This article will introduce its definition, applications, and advantages. If you are planning to make a CNC milling prototype, or need a CNC milling service, it’s highly recommended that you continue reading.
Definition of CNC Milling
To get to know CNC milling, you need first to understand what CNC is. CNC, Computer Numerical Control (also known as Numerical Control), is the automated control of machining tools using a computer. While milling is the process of machining using rotary cutters to remove material by advancing a cutter into a workpiece.
The types of CNC milling include: face milling, shoulder milling, vertical milling, horizontal milling, plain milling, angular milling, form milling, tapping, drilling and some even can do turning. Nowadays, there are 3 to 6-axis CNC mills.
Applications of CNC Milling
As a designer or engineer, it may not be necessary to fully understand all the above CNC milling types. However, if you have a glimpse of how CNC milling is applied to get your designs made, you may get some implications to come up with an easier-to-realize design in a better way, which would help a lot to make your design more manufacturable.
CNC Milling has a rotating cylindrical head and several chip-slot milling cutters which is often called an end milling cutter. It can move along a different axis, used to process narrow and long spaces, grooves, contours, etc.
There are three major types of parts that are CNC milled.
1. Plane parts
When the machining plane is parallel or perpendicular to the horizontal plane or the angle between the machining plane and the horizontal plane is a fixed angle, the machining part is known as a plane part.
According to the definition, at present, the vast majority of parts processed on CNC milling machines belong to plane parts. The feature of planar parts is that the surface of each machining unit is a plane, or can be unfolded into a plane.
Plane parts are the most simple type of CNC milling object. Generally, when a 3-axis CNC milling machine applies just two axes, those parts can be made.
2. Parts with variable bevel angles
The parts, whose angles between the machining surface and the horizontal surface vary continuously, are called the parts with variable bevel angles. Most of these parts are airplane parts, such as integral beams, frames, rims, ribs, etc. In addition, inspection fixtures and assembly fixtures are also parts with variable bevel angles.
The machining surface of variable bevel parts can not be unfolded into a plane. But during the machining process, the moment when the machining surface and the milling cutter circumference contact, there is a straight line. The best choice to machine them is to use 4-axis or 5-axis CNC milling machines. And 3-axis CNC milling machines can be used for 2.5-coordinates approximate machining.
3. Curved surface parts
The parts whose machining surface is spatial surface are called curved surface parts.
One of the features of the parts is that the machining surface can not be unfolded into a plane. The other one is that the contact between the machining surface and the milling cutter is always point-contact. Usually, we use a 3-axis CNC milling machine to produce them.
Broadly speaking, many rapid prototyping companies offer CNC milling services, manufacturing CNC milling prototypes and short-run products. And the CNC milling prototypes and components can be in plastic or metal materials. Nowadays, CNC milling is the most widely utilized CNC technology in rapid prototyping.
Advantages of CNC Milling
1. Excellent adaptability and flexibility
Via CNC milling, complex parts and those with difficult-to-control sizes can be easily produced, such as mold parts, enclosure parts, etc.
2. Stronger machining capacities than ordinary machines
It can process parts that can not be machined by ordinary machines, including complex curve parts described by mathematical models and 3D space surface parts.
3. Don’t need to change fixture location frequently
With one fixture location, you can finish producing the multi-process processing parts and don't have to change the fixture location.
4. High tolerances, stable and reliable quality
The pulse equivalent of a CNC device is 0.001 mm, and those with high precision can reach 0.1 μm. In addition, CNC machining can avoid manual operation errors. So replicable and reliable quality is guaranteed.
5. Highly automatic
Its high automation is able to reduce the operator's labor intensity, which is helpful for the automation of production management. After setting up, the machine can work on its own 24/7 without stopping.
6. High production efficiency
Usually, CNC milling machines generally do not need to use special machining equipment such as special fixtures. Instead, when replacing a part, you just need to change the processing procedures and clamping tools and adjust the tool data that are stored within the machine. As a result, the production cycle is greatly shortened. Secondly, as the CNC milling machine is combined with milling, boring, and drilling machine functions, the whole process is highly concentrated, greatly improving production efficiency. In addition, the spindle speed and feed speed of the CNC milling machine are continuously variable, which is conducive to choosing the optimum cutting parameters.
Disadvantages of CNC Milling
1. Relatively high investment than traditional milling machines
The one-time investment in a CNC milling machine is high. Besides the machine itself, other auxiliary equipment, such as a CNC tooling system, must also be configured.
2. The operator needs to be skillful
CNC milling machines require time and skills to operate and maintain a high degree of tolerance. Experienced CNC programmers even play a dominant role.
3. It is less cost-effective than a traditional milling service
CNC milling service is less cost-effective when it comes to machining small quantities of prototypes because the setup costs are relatively high.
How to Make the Right Decision Based on the Actual Situations?
A CNC milling service is necessary for prototypes if your design includes plane parts, parts with variable bevel angles, and parts with curved surfaces. How to choose the right CNC milling service provider? They should have the following capacities:
1. Basic CNC milling machines and related equipment such as drilling, grinding, cutting, EDM, and supporting secondary finishing technicians.
2. Excellent sales and engineering teams work with you to communicate easily on your project. They can provide more valuable suggestions for improving your project production as well as cost reductions.
3. Advanced quality control systems to ensure that each part produced meets the drawing requirements.
4. Highly flexible production capacity to serve you for any urgent project and to run the whole project production quickly in a short period.
5. An after-sales service team to ensure any defective parts receive a good solution and replacement. In some cases, they can be responsive 24/7.
What Is the CNC Milling Service for Prototypes You Need?
When it comes to making a prototype, a CNC milling prototype is a good choice.
The number of companies and workshops that can deliver CNC milling services is growing every year. Finding a CNC milling service provider is easy, but finding a trustworthy one is not.
A good CNC milling service provider knows how to provide the best solution based on your budget and specific requirements. As a professional rapid prototyping and low-volume production service provider, X Rapid Technologies is always considerate of its clients' needs. We also offer to suggest how to make the design feasible for manufacturing.
No matter whether your project is for rapid prototyping or low-volume production, we are confident that we will be matched. We can provide a trial order with the quality, service, and communication that meets your requirements. We also offer:
1. Fast feedback and ability to respond quickly to orders during the development, marketing launch, production, or after-sales phase.
2. Support your project material well and get the relevant test certifications.
3. Good support from design, and development to production based on expert advice, production recommendations, and smoothness to make your project competitive not only just by helping you bring your new products to the market quickly.
If you want to know more about CNC milling, CNC milling prototype, or CNC milling service, get in touch with X Rapid Technologies and discuss your requirements. You will get free quotes within 24 hours and kick-start your projects soon. Our 1-on-1 project manager will take care of your project from A to Z. We are always problem solvers and positive to every issue aroused.
FAQs of CNC Milling Services
1. What materials can you mill?
Any plastic and metal plates can be CNC milled. The most commonly used plastic is ABS and the most commonly used metal is aluminum 6061-T6. The metals we use, in most cases, are according to Chinese standards. You can also read our blog to know the 12 most widely used plastic materials. You are warmly welcome to check with us if the material you want is available.
2. How do you control the tolerances of CNC milling prototypes?
Lose tolerances are usually caused by improper clamping and material deformation. We have strict control of material quality and a complete operating process to guarantee tight tolerances. Inspection reports are available for you to check before delivery.
3. What surface treatments are available for CNC milling prototypes?
We provide a wide selection of finishing treatments for CNC milling prototypes, covering painting, bead blasting, brushing, electroplating, water electroplating, chromate conversion coating, nickel plating, powder coating, laser etching, silk screening, pad printing, and so on. To know more about finishing, you can check our blog. Let us know your specific finishing needs and we will offer you a custom solution.
4. How can I get a quote for CNC milling prototypes from you?
Just send your 3D drawings for the parts to us. Tell us your needs for material, quantity, and finishing. You will get our free quote within 24 hours. If you have detailed tolerance requirements, it's better to send us the 2D drawing for the details and inspection report. We are also open to any questions on design for manufacturability.
5. How do you ship CNC milling prototypes?
We ship CNC milling prototypes worldwide. Both international express and sea transportations are available. It depends on the time required by you to choose the suitable ways. You can also work with your own shipping forwarder. We are very flexible.