CNC Machines – Expectations versus Reality

The advances in CNC machine technology and associated computer applications have been truly astounding. From humble beginnings in the 1950s, Computer Numeric Control or CNC machines have been a focal point for manufacturers and production floors ever since. And what started as a simple exercise in X-axis and Y-axis directional control has become a universe unto itself. From 2-axis machines to today’s complex 9-axis capabilities, the world of CNC machining is no longer the domain of the shop denizen; it’s become the realm of the computer algorithm expert. But that doesn’t mean it’s the machine that can do it all. There are some things even a CNC machine can’t do.

Going Here and Getting There

To be clear, let’s review some general facts about CNC machining that everyone agrees on before going into detail. A 3-axis CNC machine travels linearly, vertically, and deeply (X-axis, Y-axis, Z-axis) over a workpiece or part. Each axis can be accentuated by having the tool moving across the axis also turn or spin on the axis, creating additional material removal protocols. From simple tasks like drilling and routing to more complex moves like creating internal decreasing-ratio curves or spirals in material. With tolerances of less than .001 mm achieved with consistency, CNC machines do what humans cannot.

Advantages of CNC Machining

There are several benefits that CNC machines bring to the table (excuse the pun), those include;

• Work 24/7/365 – These machines are titans when it comes to staying on the job. No vacations, no sick leave, just occasional shutdowns for maintenance, upkeep, and upgrading.
• Do it again! – a CNC machine can produce thousands of parts with the exact same dimensions without interruption ad-naseum. Humans can’t do that and never could.
• Rocket Scientists NOT required – CNC operations can be conducted by operators with limited training reducing the need for highly skilled technicians and keeping production costs down.
• Make prototypes using software, not machinery – Modern equipment allows part designers to determine CNC machine results without having to produce prototypes over and over again until the machine is programmed correctly.
• Less means more – It takes a lot fewer bodies to run several CNC machines nowadays. That saves a lot of costs, training expenses, and HR complications.

Downside Considerations

• $$$ – CNC machines aren’t cheap. Depending on the capabilities, programming costs and tooling required, a CNC machine can cost a pretty penny indeed.
• Size matters – A CNC machine can only do what it’s designed to do and no more. In other words, you can’t fit 5 pounds of workpiece into a 2-pound CNC machine. If production demands a part larger than the machines can handle, you’re going to have to go shopping (refer to the previous point for why that isn’t such a great thing).

Expect the Unexpected

A highly-trained CNC operator will tell you there’s nothing he can’t make, except air to breathe and sunshine for a tan. That’s not exactly true, but the fact is there really aren’t many parts that can’t be made on a CNC machine in one way or another. The complex designs turned out by today’s CNC equipment are astounding and the inclusion of Artificial Intelligence (AI) in programming and in CAD/CAM applications has set the bar even higher. New tools, materials, applications, and techniques arrive on the scene every day. It truly is a universe unto itself and worth exploring.