Claddings for harvesting machines, roof structures for buses, panels for sun beds – only a few companies can manufacture such large-size plastic parts from polyurethane. One such firm is Pestel Pur Kunststofftechnik from Chemnitz, Germany. The company was founded in 1990 by Ulf-Peter Pestel directly after German reunification. It has 50 employees on a premises of 10,000 m² and it produces components with a shot weight of up to 100 kg and a surface of up to 4.00 m x 2.00 m.
In their own mould-making processes, the team headed by Michael Legler produces the necessary mould tools from customer-specific ideas or from delivered Solidworks data. With a total weight of up to 19 tonne, they are manufactured on three to five-axis portal milling machines. Bearing in mind that milling machines have to work through the night when machining such large mouldings, two things are particularly sought-after: High machining speeds and absolute process safety.
“On the CAD side we were excellently positioned at Pestel Pur with Solidworks,” explains Michael Legler, who has been active in the company since 2011. Over the years, however, the customer parts and the moulding tools became more geometrically complex. Deep-mould cavities and complex areas visibly overwhelmed the former CAM system. Legler reports: “For a medium-sized mould half, around one hundred CNC programs were necessary and each program had to be manually edited. In part, the post-processors covered only half of the machine functions that were available in the CNC controller.” It got to the stage where Michael Legler felt that the expense of the CAM programming was unacceptable and the safety of the milling was insufficient.
So, in early 2012, he resorted to looking for a more suitable CAM system. The requirements were clearly defined: Integration into Solidworks, simple and fast programming of complex 5-axis moulds, calculation and processing of residual material, a functioning collision control and sophisticated CNC post-processors. After extensive research on the Internet about the current status of CAM systems and their scope of functions, a variety of suppliers presented their solutions to Pestel Pur on-site. Two systems made it on to the shortlist. After only two days of the testing phase, Solidcam was the clear favourite.
The CAM software was seamlessly integrated into Solidworks, fulfilled its function and exceeded all demands placed on it. Mould-making manager Michael Legler reminisces: “Of course there are special solutions for a variety of applications. But for the individual and small-batch production of moulding tools and machine components, Solidcam is ideal.” Meanwhile, the CAM programmers at Pestel Pur productively use all available 2D, 3D and 5-axis milling modules from Solidcam except the 5-axis module for tube milling and impeller milling, which are not required.
Over the past few months, the Pestel Pur team has been using iMachining technology. “We already knew about iMachining before this. But we always thought that is not for us,” recounts Legler. “Ultimately, we do not rough-machine any tool steels but instead mainly cast aluminium and high-strength rolled materials.”
Application engineer Mario Bujack from the Solidcam branch in Suhl, Germany, did however convince Legler to do a test run in early 2015. Michael Legler: “Up until then, we always used insert tools for rough machining. So our eyes lit up when we saw what end mills could bring to our machines.” The result has been a massive time saving in rough-machining. The preparation of CAM machining is now extremely simple, according to Legler, “because iMachining has the technology assistants that optimally control all machining parameters. In doing so, it includes the material to be machined, the tool used, the geometry of the model and the CNC machine data.”
What used to be a problematic workflow between CAD, CAM and CNC machining has transformed from nerve-wracking to effortless since Solidcam was introduced. Thanks to its seamless integration into Solidworks, CNC machining can now be programmed far more quickly, processing the residual material runs smoothly while the integrated machine simulation enables reliable control. Michael Legler is pleased: “It is now the case that the CNC programs can be sent directly to the control system without us having to edit them. What is more, we can sleep easy at night while the machining runs unsupervised!”