All you need to know about CMM

CMM i.e. Coordinate Measuring Machine is a device that is used to measure the geometry of the physical objects by using discrete points on the surface with the help of probe. CMM specifies the probe position in terms of its displacement from the reference point in a 3D Cartesian coordinate system. In CMM, probe plays a crucial role as it is the one which sense the discrete points and find the geometric characteristics of the object. There are various types of probe available such as mechanical, optical, laser and white light. The position of the probe can be controlled manually or with the help of computer. Both Manual CMM and automatic CMM are available in market and one can choose as per his requirement.

CMM basically allows the movement of the probe in three directions i.e. X, Y and Z which are orthogonal to each other. Each axis on the Cartesian coordinate system has a sensor that monitors the probe’s position on that axis through micrometer precision. When the probe comes in the contact with a particular location of an object, the machine samples the three position sensors and thus measures the location of a point. The common use of this coordinate measuring machine or CMM is in manufacturing and assembly process

Components of CMM

Coordinate Measuring Machine comprises three main components namely:

· Main structure or machine itself

The main structure of CMM includes three axes of motion. The body of the machine can be made up of variety of materials such as granite, steel, aluminium alloy etc.

· Probing System

Next and the most important components of CMM is the probing system. This probe is the main thing which is used to measure the geometrical position of the object. It maps different x, y and z coordinates to find the exact position of the object.

· Control or computing system

Last but not the least component is control or computing system. CMM can be manually controlled or computer controlled, depending on the machine.

Control system of CMM

CMM or Coordinate measuring machine can be either controlled by an operator or via computer. Selection of these machines is basically done on their control type.

· Manual CMM

Also, known as operator controlled CMM, this manual CMM requires an operator that physically moves the probe along the axis so as to record measurements. Needless to mention that it costs less than the automatic one and is best suited for prototype machines.

· Computer Controlled

As the name implies, this machine is computer controlled and thus highly accurate and precise. Also, this type of machines cost more and is best suited for production environment with higher volumes and complex requirements.

Multi-sensor CMM

Multi-sensor CMM, as the name implies, uses multiple sensors on a single device to find the location of the object. This type of CMM has variety of advantages such as its speed is usually three to five times faster than the simple machine.

CMM is basically mechanical systems designed to move a measuring probe so as to find out the geometrical location of an object. These machines are available in variety of sizes and design so that one can choose the device as per his requirements and desire. These machines provide accurate and precise measurement.