A Fresh Twist on Making Turbine Models
A five-axis mill-turn machine keeps things under control so that an accurate model can be completed in one setup, thereby reducing throughput time.
MCE Maschinen und Apparatebau GmbH (MCE; Linz, Austria) produces various components for large gas, steam, and water turbines, as well as for wind power stations and other segments of energy production. But before the company receives any orders for these products, realistic models must prove their efficiency, according to MCE CEO Gottfried Langthaler: “It is therefore very important for us to be able to manufacture the turbine models in high quality and, at the same time, productively with a short throughput time.”
Until recently, the running wheels were still being milled individually on a five-axis machining center and then bolted or welded together. The average throughput time was six weeks. Thanks to a few technical tricks and the Siemens Sinumerik-controlled GS 1000/5-FTD from Alzmetall (Altenmarkt, Germany), which is now used in model production at the company, Langthaler was able to reduce throughput time by up to a third—to about four weeks, depending on the product. As a qualified master of mechanical engineering and design, he already knew before purchasing the Alzmetall machine that it would be ideal for his model production if a Francis turbine (an inward-flow reaction turbine that combines radial and axial flow concepts; they are the most common water turbine in use today) could be produced from solid brass.
“I was skeptical that a machining center could do that,” he said. “After all, we must achieve a high roughing cut and smooth cycle with maximum precision and surface quality.”
Initial tests with the GS 1000/5-FTD revealed that its technical abilities were ideal. The flexibility of the unit was an asset as well. “Alzmetall adapted their machining center to our needs,” he said, “so that we can meet all the requirements regarding accuracy and surface quality—in one setting, if necessary.”
User-Friendly CNC for Milling and Turning Jobs
Because this machine must also perform turning tasks in addition to milling tasks at MCE, this requirement is also in the specification and is well within the Alzmetall machine’s capability. Buz Bozner, head of Alzmetall’s Technology Center, explained how this was accomplished: “We integrated torque motors in all round axes. We therefore achieve speeds of 300 rpm in the C axis. Our mill-turn center offers an enormous machining space that not even standard lathes achieve. Parts with a diameter of up to 1000 mm can therefore be machined. A highlight of the GS 1000/5-FTD is that it can be turned to any round axis position and level.”
The model construction experts in the energy industry have been relying on Sinumerik controllers since the mid-1990s because, according to the mechanical engineering leader Langthaler, these were always up to the task, especially in complex five-axis machining. “The handling of Sinumerik 840D CNC,” he said, “is also clear and simple on its ShopMill and ShopTurn graphical user interfaces.
“The operator can work particularly easily and clearly when a GS 1000/5-FTD with the new Sinumerik Operate user interface is used,” he added. “Operation and programming always have the same structure, regardless of whether milling or turning processes are to be programmed and set up. The operator is also supported by graphical displays and animations. Many intelligent functions are available, which are helpful, among other things, for tool and workpiece measurement. The operation and programming of 3+2 axis machining is also supported by the integrated Cycle800 functions. Animated Elements simplify the explanation of functions such as selection of the direction and free running, as well as swiveling. Both programmer and operator tasks are thus simplified.”
Another highlight of the new GS 1000/5-FTD is the Sinumerik MDynamics technology package, which is especially important for complex five-axis machining. Maximum surface quality and exact contour accuracy can be achieved even more rapidly thanks to this feature. The key is in the new Advanced Surface intelligent path control, which contains an optimized look-ahead function and an optimized online CNC data compressor. The integrated intelligent jolt limiter relieves stress on the machine mechanics because it enables gentle acceleration and deceleration despite extreme dynamic response.
Customers Reap the Benefits
As a specialist in single-part and small-series production for small to large workpieces, MCE is equipped to meet even extraordinary demands on time and with top quality. By equipping its machines with state-of-the-art technology, the company is able to achieve high throughput times in model production and pass these advantages on to its customers, according to Langthaler.
Edited by Yearbook Editor James D. Sawyer from information provided by Siemens Industry Inc.
This article was first published in the 2013 edition of the Energy Manufacturing Yearbook.
Published Date : 11/11/2013