High-speed model helicopters

When 250 km/h high-speed model helicopters take to the air, all the drive elements need to be perfectly coordinated with one another. This is ensured by high-precision components, as produced by Grenzemann Präzisionstechnik GmbH on a new Sinumerik-controlled Hyundai turning machine.

The high-speed model helicopters from the Minicopter company based in Vellmar, Germany, are fast and flexible and offer superb control. The Sinumerik 828D controlled Hyundai L210LM turning machine, on which various aluminum parts are manufactured for these high-speed helicopters, demonstrates similar qualities.

The modern L210LM turning machine with a bar loader – made in South Korea and distributed in Germany by NCT Reber Maschinen GmbH – has been in place at the Grenzemann Präzisionstechnik contract manufacturing company in Eisenbach since the start of the year. Harald Müller, technical managing director at Grenzemann, had made plenty of positive experiences with dealers and manufacturers and therefore invested in the Hyundai turning machine: “The machine is ideally suited to the drive components of various helicopter models. But ultimately, that is only a small part of what we manufacture with the turning machine.”

The company, which was founded around 35 years ago, has a workforce of 18, has 15 CNC milling and turning machines in production, works in double-shift operation, and serves many different industries. “When we started out, focusing on one customer group almost led to disaster for us. We learned from this, and today no single industry or customer has more than a 15% share of sales,” explains Müller.

Shorter retooling times possible

The qualified engineer and trained industrial mechanic identifies the good price/performance ratio as an important reason for purchasing the L210LM turning machine with bar loader and driven tools. He adds: “The technical data were also suitable, and all the trial workpieces were manufactured in the required quality and with the desired surface qualities.” For Müller, however, there are also other key factors: “NCT Reber offers very good service and was able to deliver quickly. In addition, the machine can be retooled incredibly quickly.” As the Eisenbach-based company primarily produces medium-sized quantities of 50 to 5,000 units, this is a key factor.

“That’s precisely what the L210LM is ideal for,” says Angela Reber, who is responsible for corporate development at NCT Reber. From the clamping system to the electrically adjustable bar loader and the calibration of the tool, everything functions largely automatically. This means that it takes just a few steps, and in less than an hour on average a new product can be started.

Fifty percent faster with ShopTurn

Before the machine can be set up, the CNC programs need to be written. The basis for these is usually construction drawings, which are received as PDF files. Experienced specialists at Grenzemann then handle the programming. With the new Hyundai turning machine, this task can be completed particularly easily and quickly. Crucial to this is the compact Sinumerik 828D CNC with its Windows-oriented Sinumerik Operate user interface and ShopTurn work-step programming.

Cutting machine operator Gerhard Hettich had previously only programmed G-code. But even though ShopTurn was new to him, it was not a problem, as he explains enthusiastically: “All I needed was a quick briefing, and a few days later I was quicker with ShopTurn than I was with DIN programming.” This is confirmed by his boss, Müller, who adds: “As we are not a large-volume manufacturer, it is not as important to us to squeeze out every last second of production time. It is much more important to generate a stable program in a short period of time. ShopTurn enables us to do this superbly. On average, it makes us around 50% faster, and, thanks to the integrated 3-D simulation, we are 100% fault-free to date.”

Grenzemann specialists create their programs with the help of a menu and various cycles. Particularly helpful here are the integrated drilling and turning cycles, which Hettich can access at any time via soft key: “The driven tools of the L210LM make it possible for us to turn and subsequently drill, create threads and mill various contours in a single clamping, as is necessary for the drive components for the high-speed model helicopters, for example. Thanks to ShopTurn, even the programs required for this are generated in just a few keystrokes.”