So, what exactly is a CMM? A CMM is an acronym for coordinate measuring machine. It’s a device which uses a probe to measure the geometry of objects. A CMM can use numerous types of probes such as mechanical, optical, laser, and white light. The probe of the CMM can be manipulated manually or by computer controls. A CMM’s probe position uses a reference point on the object to calculate from using XYZ axes.
The average “bridge” CMM maneuvers the probe along the X, Y and Z axes. Sensors on each axis monitor the position of the probe. When the probe contacts and detects a certain location on the workpiece, the CMM draws from the three sensors which measures the location of one point on the workpiece. The probe is moved each time as the procedure is repeated until a ‘point cloud” is created which denotes the area of interest.
A coordinate measuring machine is made up of three main components which include the main structure, the probing system, and the data collection and reduction system. CMMs are available in multiple forms such as free-standing, handheld, and portable versions. While the average CMM uses a probe that moves on three axes for measuring, portable CMMs use articulated arms or arm-free systems for measuring the workpiece.
Articulated arm CMMs have six or seven axes with rotary encoders. Optical CMMs however, use small linear or matrix array cameras that can easily take 3D measurements of many different objects. Portable CMMs do however have their disadvantages. They will always need manual manipulation by a human, and they can be less accurate than a bridge type CMM.
Conclusion
It is easy to see why CMMs are so important in a quality departments arsenal. They are very versatile and produce very accurate measurements. Fab Masters Company has CMMs on hand and they are indispensable pieces of equipment. Let our Quality Dept. use our CMMs on your next product.