EoW January 2013

Feature Testing & measuring

Be in control! Statistical Process Control is the ideal way to prevent problems in manufacturing, not only enhancing quality level, but also decreasing costs, through reduction in scrap, tool damage and machine stops. Without using the best of the available technology, however, SPC is time consuming and subject to human mistakes. It requires suitable software support and the proper system to collect measurements in an efficient and intrinsically error free mode. The first advantages in this sense were performed using quality control programmes with data input tools to achieve measurements from conventional instruments. Nowadays improvements in optical technology allow reduction in time and improved result reliability. Commonly available optical stations are well used for pre-production and final tests, but during manufacturing process face at least two drawbacks. If the station is organised to measure only the profiles, such as the ones adopting the side view on a V in glass, the operator has to handle the part to measure recess and axial holes: it works like a “semi-manual” station. If the optical station is organised to measure recesses and axial holes, in addition to the profile, it needs to place the parts with specific bits, necessarily different from those needed for other parts: the changeover and correct calibration requires time. Eldes’ new optical station Themis 2K makes use of pre-assembled frames specialised with suitable bits before starting the production. Each frame houses up to five parts, allowing measurement of five samples at the same time automatically, including pits and holes. Parts can rotate to detect concentricity, straightness and misalignments in complex structures, threading integrity, hex across corners/flats and wrench height. The basic model is used for parts with maximum length 36mm, maximum diameter 25mm, with 0.001mm resolution. A second model extends the measurement capability, using the same camera to 150mm length and 36mm diameter, thanks to the vertical movement of the frame facing the camera. The quality management software is born “before the station”, resulting from Eldes’ 20 years’ experience in this field, ensuring that the Themis station is not a standalone product requiring an interface with data storage software to be fully used within a production process. Optical measurements are managed by a module, integrated to the software suite in which control plans, job order launches and SPC analysis are managed. Starting from a “general purpose” plan, it takes a few minutes to set up a complete part template. An intuitive graphic software interface assists in this. Once the part template is complete, it can be saved in memory and recalled later. A copy of a template from a parent article is also possible. The main features of the Themis software Module for Automatic Dimensional Acquisition and SPC Analysis are: • user friendly touch screen interface • choice of the job order from a list. Selection possible using bar code reader • frequency of control in time or number of pieces, with colour alarms for the operators (red – green); integration with production data collection and dedicated alarm lamps

• state of job order (start, stop, suspended) can be managed separately or in connection with existing ERP or data collection system • declaration of defects and notes guided by catalogues, but also free if required • visualisation of technical drawing of the article, procedures, instructions, any notes useful to the operator for controlling the production or setting the machines • statistical analysis of all the acquired values (Xm/R, Xm/s, Cp, Cpk) and configurable alarms (out of limits, run, trend, middle third, out of time) • immediate operator visualisation of the new point acquired on the SPC chart, following quality rules • calibration through dot grid target with NIST certification of accuracy • possibility of association lot code or raw material identification for traceability • complete traceability of all measurements • management of production approval, supervisor control, machine capability • interface to the new optical system as well to commercial instruments, already existing optical stations and profile projectors. External stations are considered as an instrument that sends a package of measurements which is integrated in the database with all the other measurements for further analysis • control panel to see all the active processes trend, out of control and alarms Eldes snc di Bellotto Paolo & C – Italy Website : www.eldes.net

▼ ▼ Themis 2K from Eldes

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January 2013