Based in Wolfegg, Germany,
Bott Werkzeug und Maschinenbau GmbH — a manufacturer of precision-machined parts and tools that also offers a contract manufacturing service — is optimising its production processes with the help of FormControl X measurement and automation software from
Blum-Novotest, a global company that develops and manufactures high-precision measuring and testing technology. The software is being used on a Hermle C42 MT turning and milling centre producing parts made from difficult-to-machine stainless steel.
When changing a pallet, the operator enters the appropriate NC program for the blank part, with the first machine operation being probing to establish the zero point of the pallet; the machine than starts running the NC program; and because machining a typical ‘combination flange’ takes over 20hr, it is important to detect component faults on the machine early on. For instance, before the final finishing process, the relevant dimensions are measured with the probe, and the tool/program corrected according to these values using the FormControl X software.
During this complex machining process, Bott also repeatedly checks important dimensions, exchanging the probe like a tool. Norbert Leins, a CAD/CAM programmer and work planner at Bott, said: “For a long time, we couldn’t check shape and position tolerances, so when Blum asked if we would like to take part in the beta test for FormControl X, we immediately agreed because it can measure these features exactly. The software is very easy to use, and creating your first measurement programs is quick — simply a click of the mouse.”
Mr Leins defines the measuring points in the FormControl X Config-Client on the 3-D model that was previously imported. The integrated ‘context assistant’ then automatically detects geometric areas and suggests typical measuring points and standard tolerances. The measuring job is then transferred to the server and called up by the machine so it can process the measuring points.
Clamping devicesMr Leins said: “I particularly like that I can supplement the 3-D models generated in SolidWorks with the geometries of the clamping devices in the SolidCAM CAM system and then transfer this overall geometry to FormControl X. This means that the clamping situation is completely imaged in FormControl X, and collisions with the probe can be prevented as early as generating the measurement program.
“The coordinate systems are also transferred from the CAM program so the user can define in FormControl X the points and measured values that will be measured. These include diameters and groove widths, as well as the flatness of machined surfaces — and we have to stay within 5µm.”
Florian Bott, team leader of Bott’s milling facility, added: “This positional accuracy is important for the following process, when the workpieces are ground. On the one hand, we have to leave a measurement allowance for grinding, but on the other hand, the less measurement allowance there is to remove, the faster the process is. Precise machining on the turning and milling centre saves a lot of time. There is also a computer next to the machine; this allows the machine operator to view the statistics for all measuring points and react immediately if there are deviations.”
Statistical process controlErhard Strobel, a Blum-Novotest sales engineer, said: “An important feature of FormControl X is statistical process control (SPC), as this makes it possible to track the development of measured values over time and to automate the machining process with predefined warning and intervention limits. Each measurement is stored in the server database of the software and displayed in the web interface as needed.
Furthermore, if the operator wants it to, FormControl X can correct the feed values to compensate for tool wear. The SPC display shows exactly how the tool wears over time, meaning that the required action can be taken in good time. The measurement results are assigned to the current component using a unique ID; and FormControl X offers the option of automatically replacing a tool with a sister tool if wear exceeds the predefined warning limit, allowing tolerances to be maintained even during unmanned operation.
“Furthermore, a Blum LC52-Digilog laser measurement system is installed in the machine for tool measurement and monitoring; it measures both milling and turning tools. By measuring both the tools and the workpieces, we ensure that the machining processes run reliably. That said, parts produced during unmanned operation still undergo random inspections on the measuring machine the next morning.”
Blum Novotest has a UK subsidiary —
Blum Novotest Ltd — located in Burton on Trent, Staffordshire.