What is CNC milling?
Although the methods of removing materials are different, first of all, CNC drilling and milling machines and CNC lathes remove materials to produce a part. A machining center usually combines two methods and multiple tools on one machine. All of these have a multi axis motion function to guide the cutting tool around and through the workpiece to create the exact shape required.
The basic difference between the two methods is that the milling machine uses a rotary tool to cut the workpiece, while the lathe rotates the workpiece and the engagement is completed by the tool.
How does CNC milling work?
Before the introduction of computer numerical control (CNC), milling machines and lathes were operated manually. As the name implies, CNC automates this process, making it more accurate, reliable and fast.
Now, a trained operator encodes the G code (representing geometric code) into the machine, usually through software. These control milling machines, each controlling stroke and speed, so that it can drill, cut, and shape materials to meet specified dimensions.
There are many different types of CNC milling machines. The most common is a 3-axis machine tool, which moves on the X, y and Z axes to provide tools for 3-dimensional manufacturing. The three-axis machine tool can produce more complex features by rotating and resetting the workpiece to allow access from multiple angles.
On a five axis machine tool, this capability is optimized by adding motion in two directions, i.e., rotation around the x-axis and the y-axis. It is an ideal choice for producing complex and precision parts. However, the disadvantage is that using this technology will break your budget, because complexity increases costs. Believe it or not, you can define any 3D geometry with 5 motion axes. However, it is unrealistic to hold the workpiece and rotate freely in all directions. This would be a machine with 6, 7 or even 12 axes. However, unless you need extremely complex parts, you are unlikely to need such a machine -- because the investment is huge, and the size of the machine is also the same!
What is the next step in CNC machining?
As you can see, the development of more and more complex CNC milling machines requires more and more professional knowledge to operate, which requires a lot of time. Even if you outsource numerical control processing, the cost of this complexity will be higher, because professional manufacturers must recover their investment. If you have an extremely complex part that requires incredible accuracy and requires a lot of use, you may be able to justify the investment. For most jobs, 3-axis or up to 5-axis machining is more than enough.
After all, there is always more than one way to solve a problem -- for example, it is much better and cheaper to design two or more less complex parts and then bolt, weld or connect them as part of the secondary assembly process than to try to process an extremely complex single part.
So why do so many people pay attention to developing new expensive and huge machines, and the profits generated by these machines are getting smaller and smaller? It's a bit like a Microsoft office. Most of us use word, but in fact we may only use 20% of the content it provides. However, Microsoft continues to add new features, most of which we may never need, use or even know.
Instead of gradually improving the process, we think it is better to improve the process itself. This is where we can make real gains.
Process automation
Let's go back to the beginning and study the process of making a part.
All this begins with the designer designing the required parts or components on his CAD system. In general, an experienced person is responsible for G code programming of computer aided manufacturing (CAM).
However, once the design is in place, why add another step? The good news is that you can use many CAD packages to convert your CAD into G code -- but we need to go back one step.
Once you have designed your part, how do you know that it can be manufactured by CNC machining and meet the tolerance you require? Your CAD should be a digital line connecting everything with little or no human intervention.
After all, with industry 4.0, we should all live in an interconnected world. Most of the work of NC machining still depends on experienced machinists. When you send your design, there is usually a person to check whether it can be made with a known process. If not, I need to tell you so that you can redesign or optimize the design.
At protolabs, we have automated this process. Once you send your CAD data, our software will check its feasibility and generate a quote. If the proposed modifications are necessary, they will be displayed to your CAD in the feasibility report automatically generated by the software. Once you agree to design and manufacture, our software will create the code required for processing as specified in the quotation.
Faster and more cost-effective
This makes the process faster and more cost-effective, which can have a real impact on the prototype design and testing of small and medium-sized work or new parts.
Thanks to the automation, this service is the same for everyone, regardless of the size of the project. It is understandable that traditional engineering companies will give priority to projects that can make them more money -- whether it is due to the scale of work or the complexity of the components required -- of course, it depends on their ability.
The automation of the process makes the competitive environment more fair. Therefore, for prototyping or requiring a small or medium number of parts, you can still benefit from the same speed and quality of service.
Because all this information is generated and collected from the beginning, we can cut and deliver customized CNC milled plastic and metal parts in just 24 hours. If you are not in a hurry, you can choose a later delivery date and reduce your costs - so you can even set the terms yourself.
This process starts with your CAD, which means that after you design your parts, we have a digital line that we can use in the whole CNC processing process - from your computer to delivery.
Automation is not only a problem of CNC milling and turning. It includes everything from design. This is the future of CNC milling. This is the real industry 4.0 action.
