Casting and forging measuring can be laborious and time consuming in the field unless new technologies are embraced and used. Optical measuring systems are at the forefront of new technologies in the industry and can save time and effort, while returning accurate information.
One of the latest innovations comes from optical measuring specialists, GOM, in Germany with the introduction of the ATOS 3D Digitiser. Using advanced camera technology in casting applications the ATOS allows full field measuring and fast validation of the object’s complete and complex surface rather than collecting a few points with a probe and leaving large unknown areas.
Local supplier
“The technology is based on the principle of triangulation and projects fringe patterns onto the object which are recorded by two cameras. The computer automatically calculates the 3D coordinates for each camera pixel of the scanned surfaces with very high precision and resolution,” says Aurelio Grech-Cumbo, CEO of RGC Engineering, the sole-distributor for GOM and Mitutoyo CMM’s in South Africa.
“Each individual measurement takes approximately 1-2 seconds and is automatically transformed to a common object coordinate system using previously applied reference points. During measurement, the software checks online for system calibration, sensor movement or any ambient changes that might affect the measurement.”
Data on the move
The ATOS 3D optical digitiser is mobile and can simply be transported to an object, so that heavy casts, tools and models can be easily inspected right away on-site in foundries, tool- and die- shops. Due to its design, the sensor head is built to perform in harsh and adverse production environments.
As a non-contact optical measuring device ATOS is also ideal to check sensitive sand cores before the casting process.
The measuring volume can be adapted to specific measuring tasks and object sizes within a few minutes by interchangeable lens sets. Due to this flexibility, the ATOS system is able to measure objects of various sizes, from filigree injection-moulding components to a complete aircraft. Turntables, robots or multiple axis motion units are available for automated measurement of multiple parts.
Software
A software suite called ATOS Professional Software is supplied with the ATOS Scanner and provides a number of functions essential for the casting industry. In addition to full field 3D shape and dimension analysis against CAD the software allows calculation of material thickness in order to check material allowance for further processing. It is possible to control size and position of basic primitives and also virtual calipers. Inspection sections with tolerance bands are available as well as classical 2D dimensioning tools. The ATOS reference point system allows moreover checking of parting surfaces for offset, fitting and proper closing of mould halves.
For documentation and further processing the ATOS Inspection Software includes enhanced reporting and documentation functions and interfaces in order to generate standard or customised 3D measuring reports or traditional tables with CMM points. Results and deviations can be exported to various formats such as Excel, HTML, Word, etc. For recurring measuring tasks the software evaluation can be automated using macros and scripting language. GOM also provides a free GOM 3D inspection Software GOM Inspect and such measuring results can be easily shared with customers or colleagues from other departments.
Touching and probing
In the past, evaluation of optically hidden surfaces such as water jackets, cooling holes, deep pockets and deep cylinders, had to be measured on classical CMM’s, a process that is very time consuming due to necessary fixing and alignment of the parts.
The GOM Touch Probe as an Add-On to the ATOS 3D Digitiser helps to overcome this obstacle. The handheld Touch Probe enables the user to switch between 3D full-field measurement and online tactile probing of specific single points. A time consuming modification or rebuild of the sensor setup is not necessary.
The GOM touch probe is a calibrated set of point markers that are optically tracked by the ATOS 3D Digitising system measuring the online 3D coordinate of the calibrated probe tip.
A live inspection of points and primitives is available. Tactile probing of geometries such as planes, spheres, cylinders and cones as well as circular, slotted and rectangular holes and borderline segments is also possible. The Touch Probe allows fast point based probing against CAD to determine deviations to reference data also in difficult to access areas.
Lightweight
The Touch Probe allows effortless measurement over long periods and for larger measuring projects. A constant rigid mounting of the part such as on CMM’s is not necessary. Due to the dynamic referencing either part or sensor can be freely moved to find comfortable positions. The ATOS Software allows various alignment strategies at any time, while the mechanical and cable-free probe can be operated via a remote control.
An audio-feedback signals probed points and elements to guarantee a safe workflow and different touch probe sizes are available for small to large objects.
The modular concept of the GOM Touch Probe allows an adaption for many different applications via fast interchange of probe heads and extenders. In addition the user can create customised touch probes for specific tasks.
For further details contact RGC Engineering on TEL: 011 887 0800 or email: aurelio.grech-cumbo@rgcengineering.co.za
