Portalfräsmaschine ENDURA® 704LINEAR von FOOKE

Dynamics and no drift

Traversing the path with maximum speed and precision - this is the issue not only in milling, but also on the car racetrack. To demonstrate how workpieces can be milled with maximum dynamics thanks to Sinumerik One from Siemens, take the example of a machine tool from Fooke on which parts for Formula 1 racing cars are manufactured.

It is almost impossible to tell visually, but the set-up of Formula 1 racing cars is adjusted and optimised for each individual racetrack and its conditions. In order to produce the necessary parts for the racing cars, many racing teams have their own machines. The demands on these machines are very challenging. Though soft materials such as polyurethane foams are also machined on them, they are ideally designed for machining tough materials with high strengths to enable the production of titanium inserts, for example. With its high rigidity, machining speed and positioning accuracy, the ENDURA® 704LINEAR portal milling machine from FOOKE, equipped with Sinumerik One, has everything a milling machine needs to work in Formula 1. Horst Eckersberger from FOOKE's sales department comments: " Due to their mechanical properties, our in-house manufactured structural components ensure that as few external influences as possible arrive at the tool centre point". The fine-tuning of the FOOKE machine was not done with a specific workpiece in mind, but rather more generally, having a greater picture in mind: "The ENDURA® 700 was the first machine type that we equipped with Sinumerik One. In order to be able to evaluate the performance of the latest CNC control generation from Siemens, we put it through its paces. Among other things, our most notorious Mold&Die dynamic part was used as a benchmark for this," states Eckersberger. This complex part is made to confront the machine and its control system with a variety of challenges typical in mould manufacturing. The result was impressive: the machining time beat the previous record. Moreover, the machining time could be reduced by about 25 % in direct comparison with an identical machine controlled by the previous Sinumerik generation. This has all been achieved without any loss of quality. In the machining industry, where a lot of energy is invested in the smallest possible improvements on the shop floor, that's quite a statement. Fast machining times with maximum precision and quality are also important for Formula 1 applications, because a glance at the racing calendar shows that the time windows for tuning the racing cars for the next racetrack are very tight. Therefore, it is crucial to be able to produce many prototype components in a short period of time.

High dynamics
There are numerous reasons why the machining time of the Sinumerik One-controlled machine is reduced so much while maintaining the same quality: for example, it has a Formula 1-fast PLC that has accelerated the cycle up to a factor of 10. However, the high dynamics and the increase in machining speed are mainly due to the new Sinumerik One Dynamics technology package with the Sinumerik One Top Speed Plus function. By the improvements of the manufacturing process realised by this, the mechanics can be operated to its physical limits: Performance is increased by always allowing just the right amount of contour inaccuracy. To achieve this, the behaviour during acceleration is regulated by an innovative filter technology, among other things, and a higher jerk is permitted.

Reduced machining times
Nevertheless, overshoots do not occur, especially at reversal points - to which the high rigidity of the FOOKE machine also contributes. "During the performance test, the machine did not lose its balance even during maximum-speed roughing and pre-finishing," says Dennis Hüning, Head of Technology Centre and Application Engineering at FOOKE. Dynamic and control parameters are automatically adapted to the current axis speed and the axis position. Thus, the high dynamics result in significantly shorter machining times with simultaneously high contour accuracy - without leaving any marks on the milled part. With complex NC programs, it is part of the process for the machine operator to check individual blocks before the NC start, for example in the mould making quick view on the monitor. Once risky or particularly important program parts have been checked by the machine operator in this way, the milling cutter can start the race. With its multi-core architecture, the Sinumerik One offers very high performance in this regard and outputs the quick view without any delay. " Overall, the control is noticeably fast," says Hüning. "Machining, simulation, and collision avoidance - these processes can all run simultaneously without any influence on each other or slowing each other down. "Having a finished workpiece processed quickly with a surface that passes all quality checks, i.e. everything runs smoothly, is not something that can be taken for granted. In the specific example of the FOOKE ENDURA® 704LINEAR, the linear motors in all drive axes worked together perfectly under the direction of Sinumerik One. However, this is only possible if there is good cooperation during engineering and commissioning: "And that worked out well," says Matthias Wesseler, Team Leader Commissioning NC/PLC at FOOKE. "We are so convinced of the technical cooperation with Siemens and the new Sinumerik One that we will recommend this series in this configuration in the future."