What is CMM Programming, and How is it Related to CNC Machining?

A CMM, or Coordinate Measuring Machine, is an inspection device that allows the physical characteristics of a part to be measured digitally.  CMMs can be controlled manually or through a pre-written program executed on the control to automate the inspection process.  The CMM program can be written to measure dimensional requirements of a conventional print or the model-based definition (MBD) requirements that are becoming more prevalent in the industry today, particularly in aerospace.  Modern engineered components have more and more non-prismatic features or complex geometric dimensioning and tolerancing (GD&T) that are increasingly difficult to measure without the use of custom inspection equipment or check fixtures.  A CMM provides an avenue to measure these complex features on many different types of parts without the need for custom tooling. 

CNC Machining technology is producing increasingly complex parts.  With 5-axis machining and multi-axis turning becoming more common, manufacturers are able to produce parts of a complexity not imagined only a few years ago. CAM software is able to generate sophisticated tool paths in the digital environment, create a 3-D simulation of the entire digital workspace to show material removal and prove the tool path is safe and collision-free, and output enormous, complex NC code files to drive the machine tool. 

In the modern engineering and manufacturing environment, the entire manufacturing process is controlled digitally. From the original design development in CAD software to the CNC programming in CAM software to the NC code that is driving the machine cutting the part. With the use of CMMs, the inspection process is also able to be performed digitally. By using the original digital CAD model to create the CMM programs, the physical part is being compared to the original three-dimensional digital artifact that contains all of the design authority. This is generally a better representation of the design intent than a two-dimensional drawing. 

What are the benefits of CMM inspection over traditional inspection? 

Because the digital model of a part is used to program the CMM inspection routine, the CMM is directly inspecting the digital features of the original design.  When a part is inspected to print, there is an opportunity for the inspector to interpret the print differently than the designer or draftsman intended. The digital artifact used to create the CMM programming leaves little to no room for interpretation. Because the CMM is programmable, the process is also automated. CMM inspections of first production pieces or first articles can reduce the inspection time by over 90%. This benefit becomes even larger when inspecting production parts where the CMM can create automated, repeatable results when sampling or 100% inspecting production orders.  The CMM can also take all the measurements at a wide variety of ranges to replace calipers, micrometers, height gages, pin gages, radius gages, etc. No need to pull out half of the inspection cabinet to perform an inspection when the vast majority of it can be done on the CMM. 

Why choose Cutting Edge Technologies for your manufacturing challenges? 

The team at Cutting Edge Technologies collectively has many decades of CMM programming and inspection knowledge and well over a century of manufacturing experience. We have programmed, manufactured, and inspected many different types of parts for a wide variety of industries and have the expertise to make sure your project runs efficiently and is inspected accurately. It is often difficult to find highly skilled CNC and CMM programmers, and in today‚Äôs fast-paced manufacturing environment, it is often difficult to staff effectively for the ever-changing workload. CET has the ability to assist with short-term surge capacity when needed and also partner with you long term for expert support.  Contact us today to see how we can support your manufacturing needs.