In the passing lane with Tebis
Fast, reliable manufacturing of high-quality motorsports components
Tebis is a partner of the "Digital Factory 4.0" initiative, which was represented with its own pavilion at the Mecspe 2017 international manufacturing industry fair in Parma, Italy. A focal point of the initiative is the manufacturing of high-quality components for motorsports. Tebis was part of the manufacturing chain for machining a hub fixture for Formula 4 vehicles.
Many prerequisites have to be met to manufacture precise, high-quality components for Formula 4: The tool and machine center must fit together and the numerical control must be exact. Powerful strategies for toolpath calculation are also required, as are accurate criteria for point distribution and analysis of the machining data.
To optimize the production process, the CAD/CAM software must determine a perfect toolpath for best utilizing the latest machines. Tebis handled all 3- and 5-axis machining in the motorsports manufacturing chain for a front hub fixture made of Ergal for Formula 4 vehicles. The specialists tested a broad range of CAD/CAM functions in Version 4.0 Release 3 of the software. The manufacturing chain was implemented in collaboration with Heidenhain, Sigma, Sorma and Schunk.
Automatically repair original surfaces
It is first necessary to prepare a precise and reliable CAD model for the hub fixture to achieve high machining quality with minimal manual reworking. To do this, Tebis calculates the toolpaths directly from the exact mathematical surfaces, not from an approximate substitute model (polyhedron). The quality of the CAD surfaces is thus transferred directly to the CNC programs.
Tebis uses functions for automatic repair of the original surfaces to test and optimize the CAD model. The functions search for topological defects, segmenting and detachments, and corrects them as necessary. The mathematical model has a significant effect on the structure of the toolpath: For highly segmented surfaces, a significantly higher number of points is generated to define the toolpath in NC programming. The calculation and machine run times are correspondingly longer. The layout of the toolpaths were optimized for the component geometry using specific functions that incorporate the new structured guide curve technology. Lateral stepover of the paths remained unchanged (3D stepover).
Tebis worked with optimized point distribution to achieve the desired high level of machining quality. Point distribution is one of the factors that most heavily influence the quality of the milling toolpath. Tebis conducted a specific study of this in conjunction with Heidenhain, the world's leading manufacturer of NC controls. The study showed that very different machining results can be achieved with the same machine despite unchanged chord errors. This was done by adjusting only those algorithms that control point distribution during toolpath generation. Tebis V4.0 R3 has developed six different criteria for point distribution that can be selected depending on the available instruments and desired degree of machining. The performance of the latest NC controls is reflected in the ability to use thousandths for chord errors without affecting calculation times, and the ability to generate NC program files to four or five decimal places.
Detecting and correcting collisions in advance
Standardized and calibrated clamping systems also ensured maximum precision as well as optimum accessibility on all five sides during positioning of the blank. This optimized the procedures and the sequence of steps while reducing tool changes to a minimum.
The kinematic simulation in Tebis also played a key role due to the significant size of the clamping fixtures. Because the simulation provides a virtual model of the actual production environment, the entire machining cycle could be checked in advance. This optimized machine placement and modification, and enabled safety issues regarding collisions or end stops to be detected in advance. The optimal solution improved overall efficiency of the production process and reduced downtime. This simultaneously reduced the risk of errors that can result from manual intervention by the machine operator.
These Tebis technologies enable a reliable and safe production cycle in the manufacturing chain. Components are produced that perfectly correspond to the CAD reference model and meet the high quality standards required in motorsports.
Sara PittatoreMarketing contact +39 011-53.68.104 email@example.com