Every time a CNC machine cuts a piece of plastic, it is the result of a deep unification of man, machine and computer. Sure, the end result is just a tool drilling into material, and what’s so special about that, right?

Well, long before any cutting or drilling takes place, it is the job of a human being to articulate precise instructions to the robotic machine that will be doing the work. The problem is, robots don’t speak English — or even human, for that matter.

A sophisticated computer must act as the translator.

Language Lessons: Getting the Software and the Machine on the Same Page

CNC programming is a key first step in the CNC cutting process. An operator uses computer aided design (CAD) and computer aided manufacturing (CAM) software to generate computer code.

First, CAD software is used to plan the cutting operation by drawing a picture of the part to be cut. Then, CAM is used to convert the picture into a series of lines of computer code that the CNC machine will understand and obey. This is sometimes a two-person job — one to create the designs using the CAD/CAM software, and another to retrieve those designs and turn them into CNC precision.

Finally, the computer code generated by the CAM software instructs the CNC machine. It tells it which cutting tools to use, where to find those tools on its 8-spindle tool changer, and how fast to cut. The precise angles, dimensions, lengths, and depths of each cut are all completed based on the coded instructions. By retrieving this computer code from memory, the operator equips the CNC machine with exact instructions — and the right tools to carry them out. The software and machine work together for precision cutting.

Give the Router the Right Tools, Then Tell it How to Use Them

Let’s say an order requires two different sized holes to be drilled into a piece of acrylic. There are 8 tool positions between T-11 and T-18 on the 8-spindle tool changer for the CNC to choose from. If the programmer selected the use of a 1/8″ diameter bit in the T-12 tool position and a 3/8″ bit in the T-13 position, then the CNC operator has to have a way to know to insert those tools into those positions on the tool changer. For this purpose the programmer provides a picture of the cutting plan to the operator in pdf format.

So the CNC now knows what size holes to drill and what tools to drill them with — but how does it know where to drill, how deep to make the holes, and in what dimensions to drill them? To visualize how this works, use CAD (computer aided design) software to draw a precise picture of the part to be cut. Then use the CAM portion of the software (CAM is short for computer aided manufacturing) to convert the picture into a series of lines of computer code that the CNC machine will recognize and obey.

Only now — armed with both the right tools and specific instructions — can the machine do its job of CNC precision cutting and drilling.

Protecting the Product — and Our People

The CNC router is a big, powerful machine that the operator must respect at all times. The slightest miscalculation could result in damage to the machine, material or — in the worst-case scenario, which we obsess over preventing — to the human operator.

Ensuring operator safety requires strict protocols, including:

  • The installation of a highly visible red line, beyond which is a dangerous area that the operator should never enter when the machine is running.
  • Mandatory use of safety goggles to protect against flying chips and other projectiles.
  • The necessity of a “dry run” to make sure the settings are correct before material is cut.

Ensuring excellent quality requires strict protocols as well, such as:

  • Use of the correct cutting tools consistent with the CNC program
  • Ensuring bits are changed before they become too dull
  • Machines are run at the correct speeds, not too fast and not too slow
  • Parts are fixtured securely, usually with good vacuum techniques

Precision manufacturing requires man and machine to become one entity through the adhesive power of computer technology. Each performs tasks that the other couldn’t on their own, and the end result is flawless manufacturing.