Precision grinding machine

An automatic execution grinding machine having a base and, on said base;

• a worktable provided with a workpiece spindle;
• a truing turret provided with one or more truing tools, each truing tool having at least one truing edge;
• a toolholder turret provided with one or more grinding tools;
• moving means for effecting relative displacements along at least one of an X axis and a Z axis between said toolholder turret on the one hand and said worktable and said truing turret on the other hand;
• and numerical control means arranged for automatic execution of successive sets of said relative displacements, said sets comprising sequences of grinding operations effected with said at least one grinding tool on at least one surface of a workpiece held by said spindle, wherein the improvement comprises:
• a first follower on said toolholder turret, having a fixed active position with respect to said toolholder turret, and having at least two sensor faces oriented on said X and Z axes respectively, said faces having fixed positions relative to one another;
• a reference block having a fixed active position with respect to said base, provided with at least two reference faces oriented on said X and Z axes respectively;
• and
• said numerical control means automatically controlling starting-up operations to perform a measurement taking step whereby said first follower is successively brought into predetermined relative positions with respect to said at least one truing edge and said at least two reference faces of the reference block so as to bring said sensor faces into coincidence positions with said at least one truing edge and with said reference faces, each sensor face being brought in a coincidence position with a corresponding reference face, and to provide and store data corresponding to an actual relative position of said at least one truing edge with respect to said reference block.