The idyllic countryside around the Chiemsee is the perfect location for relaxing and regeneration and countless holidaymakers flock to the region every year. In a location where others go on holiday, Georg Pfisterer and his 20 members of staff work on high-precision components for laboratory and medical devices and equipment. One of these is also an ACURA 65 from HEDELIUS, which they have been utilising since 2017.
Pfisterer Feinwerktechnik GmbH was founded 18 years ago in Bernau by the Chiemsee. The medium-sized company produces high-precision small and very small parts for demanding industries in a two-shift operation, for branches such as medical and laboratory technology, but also for the semiconductor industry and specialised mechanical engineering. "Our customers are small, medium and large companies from the region for which we manufacture products, and for their worldwide locations. We also have customers from Switzerland, Austria, China, Malaysia, England and the USA," says company founder and CEO Georg Pfisterer. All these companies rely on the high quality of the contract manufacturer, which operates its own component assembly service. The CEO explains: "The quality standard required is often very high, many of our customers are certified and require test reports and protocols for the documentation. We have to fulfil these demands. In order to achieve this, we have one member of staff who is exclusively responsible for quality assurance.” And not only for where quality is important. The company also sets high standards for training precision mechanics who specialise in precision mechanical engineering. Pfisterer only employs very well trained, skilled workers who can comply with high quality requirements.
Pinhead sized milled parts
This is important, because the size of the components themselves already suggests that machining is not entirely easy. This partially involves very small, precise work. “On average, the milled parts are about as large as a matchbox, whereby the smallest parts are the size of a pinhead and the largest components have the dimensions of a shoe box," is how Pfisterer describes the workpieces. This thereby states one of the challenges involved. The workpiece must however be machined very precisely. The tolerances are often measured in hundredths. For example, fits with an accuracy of 6 µm are not uncommon. These machining operations are executed on, among others, an ACURA 65 from HEDELIUS Maschinenfabrik GmbH in Meppen. The 5-axis machining centre with rotary tilt table from the northern German manufacturer was commissioned for operation in 2017. “When it comes down to precision, we can also mill the smallest parts on the ACURA,” says Georg Pfisterer. “We entrust the machine with the accuracy.” Aluminium and plastics are machined mostly but stainless steel and titanium are also milled with this compact machine. Since a lot of aluminium and plastic has to be cut and machined, the 5-axis machine was equipped with a HSK A63 spindle and set up for 18,000 rpm. Another reason for the high speed is the very small tools which are frequently utilised.
The entire part spectrum is processed at the machining centre of the contract manufacturer. However, the compact milling machine is most frequently used for recurring parts and medium-capacity serial production as these are the areas where the HEDELIUS machine impresses with its great flexibility.
Fulfilling deadlines is decisive
The Managing Director explains: “Our customers order batch sizes ranging between one and 500, sometimes once a week, monthly or quarterly recurring parts but often just one single part. We therefore must be able to react. Adhering to deadlines and on-time delivery are decisive for us.” For this reason, the ACURA 65 was additionally equipped with a zero-point clamping system as well as a standby tool magazine with cone cleaning station. In addition to the 65-fold standard magazine, which can be consecutively operated from the front during main machining, an additional 180 tool places are available. “The magazine on the ACURA 65 is really ingenious. Utilising the standby magazine and the zero-point clamping system enables us to significantly reduce set-up times for machining recurring parts. Vices are pre-prepared and tools are available immediately,” says Georg Pfisterer, who is very enthusiastic about the system.
Machine operating made as simple as possible
Alongside the high levels of flexibility, capacity and performance, other reasons were also crucial in the decision-making process for purchasing the compact machining centre. With travels of 700 x 650 x 600 mm (x/y/z) on a footprint of 2725 x 2850 mm, the ACURA 65 provides large machining possibilities in the smallest of spaces. This compactness was worth its weight in gold for the precision engineers from Bernau, space is always limited in the production hall. Twelve CNC lathes and milling machines are already in use here, another lathe/milling centre will be delivered shortly.
Even though it has a compact design, the machine surprises with a large sliding door and large viewing window. The machine operator can get very close to the machining table when the door is open. “The ACURA is very accessible, that is an excellent benefit”, Georg Pfisterer really appreciates the machine design. In order to keep operation as simple as possible for the staff, a Heidenhain TNC 640 was selected as control system. “Our staff are familiar with Heidenhain, we also have the control system on other machines. We wanted to exclude a mixture of different control systems”, is how Georg Pfisterer explains the decision. Pfisterer Feinwerktechnik staff often programme components on the machine, more complex parts are programmed via a CAD programme. Two of our staff spent two days at HEDELIUS in Meppen for training and were able to get started on the first ACURA right away. Georg Pfisterer is satisfied: “My staff were impressed with the training provided. Although both participants at the training course were already very well trained, they still learned a lot at HEDELIUS."