Entry-level CNC solution

With a colourful ceremony Siemens introduced the Sinumerik 808D entry-level CNC solution for standard lathes and milling machines, on this year’s CIMES, China's principle machine tool trade fair in Beijing.

With the new Sinumerik 808D, Siemens Drive Technologies Division has developed a controller designed to bring the benefits of CNC technology to the lower end of the performance range. This compact, user-friendly entry-level solution is used to perform simple turning and milling applications, and is set to replace the Sinumerik 802S in the future. As a panel-based controller, it comes with all the necessary interfaces including PLC inputs and outputs integrated in one compact device, considerably simplifying the effort involved in wiring. The machine control panel is connected using USB, and is equipped with the same ergonomically designed override rotary switches as in high-end CNCs. The USB port on the front permits the use of a USB stick for easy transmission of part programs and tooling data.

The Sinumerik Operate Basic user interface comes with a new dialog-based assistant called the Sinumerik ‘startGuide’. This guides the user step by step through the machine set-up process, minimizing the time spent on commissioning. With the aid of ‘startupAssistants’ both prototype and series machines can be simply commissioned, while the ‘operationAssistant’ supports operating staff through every step of the machine set-up and programming process.

Overall, the completely revised Sinumerik Operate Basic draws heavily from the operating philosophy of the higher-end Sinumerik Operate system. This applies not only to the menu structure but also to the programming. The ‘programGuide Basic’ feature permits simple programming with the aid of graphically-supported cycle screens and a convenient contour calculator. It is also possible to reuse part programs from other controllers which support ISO code, making it possible to alternate between DIN and ISO programming languages even within a single part program. As with all Sinumerik controllers, the user interface offers an online language changeover facility.

The Sinumerik 808D is used in standard lathes and milling machines with up to three axes and one spindle. The CNC calculates with an accuracy of 80-Bit-NanoFP to prevent internal rounding errors. Even though it is the smallest member of the Sinumerik family, the 808D comes with intelligent MDynamics path control including a ‘look-ahead’ function which allows optimized motion control for increased productivity coupled with improved surface finish quality. The high computing power and optimized technology cycles of programGuide Basic also make for high CNC performance. The ManualMachine plus (MM+) option paves the way for the transition from conventional machine to CNC programming. A machine equipped with this function can be operated using handwheels in the same way as a conventional machine, but with all the benefits of CNC-aided technology cycles.

In terms of the drive system, the controller comes with a semi-servo solution based on the Sinamics V60 drive system used in combination with the Simotics 1FL5 servomotors. Using the pulse-direction-interface, the CNC supplies the drive with set-points, which are implemented by the drive in a closed speed and position control loop with the Simotics motors. In part due to the integration of a large heat sink in the drive system, which eliminates the need for a fan, the integral CNC system is able to withstand even the toughest industrial environments. The Sinumerik 808D also benefits from an IP65 protection level at the front of the control panel.