2 Basic Geometry for CNC Machining ...........................................................................21
2.1 Coordinate systems on CNC machine tools .......................................................................................21
Types of coordinate systems..........................................................................................................21
Cartesian coordinate system ..........................................................................................................21
Polar coordinate system ....................................................................................................23
Coordinate system definition with reference to machine or work part ...............................24
Feed and Turning Axes on CNC Machines ....................................................................................28
Location and Designation of the NC axes..........................................................................28
Directions of motion on CNC machine tools......................................................................29
NC compatible dimensioning .............................................................................................29
2.2 NC Mathematics .................................................................................................................................33
Basics of coordinate point calculations...........................................................................................33
Characteristic values of a triangle......................................................................................33
Angles of the triangle .........................................................................................................33
Right-angled triangle..........................................................................................................34
Trigonometric functions .....................................................................................................35
Calculation of NC coordinates ........................................................................................................36
2.3 Zero and reference points on CNC machine tools..............................................................................38
Types of zero and reference points ................................................................................................38
Setting the work part zero point W on a CNC lathe........................................................................41
Setting the work part zero point W on a CNC milling machine.......................................................42
2.4 Numeric Controls on CNC Machine Tools..........................................................................................53
Control chain and control loop ........................................................................................................53