Gears are crucial components for modern precision machinery as a means for the power transmission mechanism between parallel, intersecting and non-intersecting cross-axis shafts. Gears have been designed and manufactured through various procedures. The spiral bevel gears (SBG) are special gears that their design and manufacturing is research filed of the most of industries. Recently, special CNC based gear manufacturing machine tools are used to produce various gears especially spiral bevel gears (SBG). Use of special CNC based gear manufacturing machine requires a large investment for obtaining various kinds of special machinery and cutters dedicated to a very limited In this research, CAD/CAM and mechatronics technologies were used and a mechanism was designed as forth Axis that interfaced with a 3-axis milling machine. This new mechanism is a flexible system which can easily be changed depending on the type of gear which is manufactured. First of all, the process was tested by developing a CAD/CAM system composed of graphic simulation softwares such as SolidWorks and Visual Nastran. WPL software is also used to control rotation of the forth axis. PLC, inverter, encoder, photo electric and proximity sensors are some mechatronics instruments that have been used in this research. The new presented method is a multi-discipline system which merges different technologies such as solid mechanic design, manufacturing and automation. Keyword : CAD/CAM, CNC, Mechatronics, Spiral Bevel Gears, PLC, Inverter, Encoder, Photo electric sensors, proximity sensors