A gear is a rotating circular machine part having incising or, in the case of a cog or bull gear, inserting teeth (called a cog) which meshes with another (compatible) toothed part to transmit (convert) torque and speed. The fundamentals behind how gears work are similar to the fundamentals of a lev

The coordinate measuring machine​ is a measuring system that detects the three-dimensional coordinates of the surface points of the workpiece through the relative movement of the probe system and the workpiece. By placing the measured object in the measurement space of the CMM, the coordinate position of each measuring point on the measured object is obtained by using a contact or non-contact detection system.