For the final touch:  Processing Skis with Schleicher Control Technology

Equipment is an important factor for all skiers, whether amateur or pro-fessional, and needs to be maintained regularly and adapted to suit diffe-rent snow conditions. The Italian company Mantec offers innovative tech-nology which makes the arduous waxing and stripping of skis a thing of the past: Their machines grind fine, high-precision profiles into the bases of skis using control technology from the electronic specialist Schleicher in Berlin. Different microsections allow skiers to adjust their equipment to the respective snow consistency, the type of competition and other condi-tions, thereby improving the sliding characteristics of the skis conside-rably.

The control solution 

Schleicher Electronic offers high-performance control technology tried and tested in special application areas like the one described here. An XCx 300 in the Man-tec Ski grinding machi-nes coordinates the movements of the grin-ding disc and the ski in three axes. This control-ler combines CNC func-tions and a PLC accor-ding to IEC 61131 to provide a flexible, cost-effective solution. The XCx 300 is perfectly suited for use in the ski service due to its practical input options: It is programmed using simple parame-ter inputs available in several languages and specialist personnel are not requi-red. You can save successful grinding patterns and print profiles for individual skiers in the program memory of the controller and retrieve them again when needed. 

Fig.: 1

Demonstration of a Mantec ski grinding machine

Fig.: 2

XCx 300 with RIO expansion modules

As with all Schleicher XCx controllers, the most important characteristic of the XCx 300 is its openness, which is demonstrated by the combination of CNC and PLC through a common communications buffer (see box), the connection of various drive systems, the incorporation of important field bus systems as well as communication via OPC and web servers. The controllers in the XCx family run under the realtime operating system VxWorks; their CNC software controls four interpolating axes with a minimum cycle of 1 ms. The PLC functions can be scaled via cyclical and event tasks and individual program modules can also be run within the CNC cycle. The heart of the XCx 300 is a compact basic module for assembly on the C-rail. The RIO direct interface can be used to connect up to eight expansion modules from the RIO system family without a field bus, which allows the XCx to operate up to 256 quick I/O points directly in the positi-on control cycle. Standard equipment includes an Ethernet interface, an RS 422 jack to connect operator panels, an RS 232 interface for programming as well as two quick interrupt inputs/outputs. Drive interfaces such as the Sercos Inter-face or Control Techniques‘ SLM as well as the field bus interfaces Profibus-DP, CANopen or RIO-direct can be integrated via the extension module slot.

More than the sum of the individual components: PLC and CNC perfectly combined

The combination of numerical and sequential control in XCx controllers is implemented by Schleicher using a special architecture: Both areas of the cont-roller use a joint communications buffer to data exchange. CNCs and PLCs always work synchronously, as a PLC task is permanently linked to the interpo-lation. The cycle time of time critical, high priority PLC program modules there-fore precisely follows the CNC interpolation cycle under the XCx realtime multi-tasking operating system. In addition to standard functions, Schleicher-specific algorithms for controlling robots or synchronous axes, for example, are also available to the CNC. Up to eighteen user tasks can be assigned to the PLC that controls and monitors all the peripherals.

Fig.: 3

A structural feature of the Schleicher XCx controllers is the central communications buffer for the synchronized CNC and PLC.

The coupled software architecture enables XCx models to control machines more quickly, flexibly and reliably: A machine engineer can arrange for all the numeric or geometric actions performed by an end user e.g. before implementa-tion in realtime, to be checked by a PLC user program, which then activates a warning message in the event of a malfunction. The controller will work with almost any external operation and visualization device, ranging from a cell pho-ne to a PC. XCx configuration, diagnosis and maintenance functions can be accessed from almost anywhere: on site, in the local network and over the in-ternet. Controllers can also be supplied with an integrated web server, which dynamically supplies current actual values to every Java-capable standard web browser.

The result: Fully automated by the machine

Fig.: 4

Grinding stone and ski in a Mantec machine

The Ski Numericontrol Easy grinding machine processes skis fully automati-cally. The ski is fixed in place and guided through the machine, where a dia-mond encrusted grinding disc creates the required profile. The pressure used the push the grinding disc onto the ski can be adjusted to allow different profile depths along the entire length of the ski. However, this does not cause any mo-re wear than if you were to wax and strip the skis as normal. The integrated four-axis CNC controller enables the accurate adjustment of the grinding para meters to ensure a high-precision, fiber-free profile structure. 

Conclusion 

With the development of the Ski Numericontrol Easy, the numerically controlled grinding technology has made its way into ski servicing. Schleicher Electronic was heavily involved in implementing this innovative idea: For several years now, Mantec has been relying on the problem-solving expertise and many years of experience in the Berlin company. Since 2004, the XCx 300 has been used as a controller in Mantec machines, which are used by the Italian Winter Sports Federation F.I.S.I. and for the production of high-quality brand name skis.