Computer numerical control, CNC, has been used to program in turning machine as early as the 1940s and it continues to be a mainstay of manufacturing technology. Until recently operating a CNC machine required the skills of a skilled programmer, but CNC automation is standard now for machining and many other manufacturing operations. Still, it’s not universal – and some people are new to manufacturing altogether – so what do machinists and operations need to know before adopting CNC automation?
1. Why are you automating? The first question any manufacturing business owner should ask is, “Why are we automating?” If you haven’t already adopted CNC automation, what sparked your interest in making this change?
Some businesses may adopt CNC automation as the logical next step in a long-term plan. Others may be automating as to keep up with a changing and always competitive market. The difference between these two is that the first approach is proactive, while the second one is reactive.
A reactive response isn’t always a bad thing, nor is it a poor reason for exploring CNC automation. It requires caution, however. There’s always a temptation to jump into something with both feet, without the necessary training and preparation. Such a leap could leave you with a lot of high-tech equipment that no one knows how to use.
2. Exploring CNC best practices. Traditional CNC manufacturing requires human control, with a technician managing one or more CNC machines. This operator is in charge of making necessary manual adjustments, providing raw materials for manufacturing, and replacing parts as they wear out or as the need arises.
Manual machine operation is not efficient. Machine shops relying solely on manual operation will require longer lead times and endure quality-control issues.
CNC automation can expand the scope of a production process – configuring a machine tool and auxiliaries like robots that take on some of the responsibilities of a human machine operator. CNC automation can set up a system to run 24/7, if desired, assuming there is enough raw material to supply the machine.
This sort of “perpetual operation” has downsides. Cutting tools and other components wear out twice as fast and these systems still don’t operate as fast as they could with a more efficient and effective strategy.
Intelligent CNC automation adds more to the toolbox: machine learning and artificial intelligence, helping to to bridge the gap between manual and automated CNC manufacturing.
When paired with networked sensors as part of the industrial internet of things (IIoT), machine learning systems can collect data about every aspect of the operation, making decisions in real-time or sending alerts to human operators when the system comes across a problem it can’t solve or a decision it isn’t programmed to make.
3. Cutting-tool tolerances. One important aspect of a CNC operator’s job is to ensure the cutting-tool tolerances are within acceptable limits. Manufacturing contracts, such as those for aerospace applications, often require the highest-quality products. A cutting tools that is worn down by a millimeter may not seem like a big deal until you’re managing tolerances measured in microns.
If you’re considering CNC automation, do you have the ability to measure the condition of your cutting tools before each step of the program? Monitoring cutting tools before and after each step will prevent quality-control problems from emerging from automation.
Implementing a tool-change practice if existing cutting tools don’t meet the expected tolerances can prevent quality-control issues, but that does require adding a step in the program.
4. CNC machine flexibility. How flexible are your machines? Can they switch smoothly between projects, or do you find yourself delaying production while changing cutting heads, uploading new programs, and loading raw materials? CNC automation can help improve flexibility, but it requires a program to transition from one project to the next.
Consider the flexibility of your existing machines. Figure out where you could improve and where automation could help move things forward more efficiently.
5. Automated decision making. One of the biggest challenges in CNC automation is the necessity to turn the entire process over to automation. We’re used to being on hand and able to step in if something goes wrong or a decision needs to be made. With automation, you may find your priorities shift away from constant monitoring, allowing you to focus on other tasks.
These systems make decisions automatically based on a set of IFTTT (If This, Then That) commands that outline their behavior, and the changes the autonomous systems are allowed to make on their own.
6. Controlling thermal expansion. Thermal expansion may be the most significant challenge following a CNC manufacturing set-up. Automated processes generate heat, which causes metal to expand and distort. That distortion will negatively impact the finished product, creating a quality problem.
Temperature sensors and heat mitigation systems – again leaning on IIoT technology – are a must for CNC automation. Without a sensor telling the system to throttle down or back off as the system cools off, thermal expansion will be a perpetual threat.
Automation is becoming an essential aspect of manufacturing, but jumping in feet first is akin to investing in equipment you don’t know how to use. Start by figuring out why you are automating – and move forward.
Emily Newton is the Editor-in-Chief of Revolutionized, an online magazine exploring the latest industrial innovations.
