sSHOP SOLUTIONS
Problem Solving on the Shop Floor

Tooling a Large Machine
for Turbine Shaft Machining
Scaling up and tooling a multiproduct machining center“Until now, the workpiece weight between chuck and(mpmc) to machine a giant turbine shaft for a US power

tailstock was limited to a maximum of 30 t,” said Wernerengineering group was a challenge for Weingärtner Maschinen-Pommer, Weingärtner engineering and sales. “We had al-bau (Kirchham, Austria). The timeframe and sheer size of theready thought about how we could scale up our mpmc 1200

workpieces required Weingärtner to scale up one of its advanced

machining center to accommodate larger turning diameterstechnology mpmc 1200 machining centers to be able to ma-and heavier workpieces. In this respect, we were ahead ofchine giant turbine shafts used in gas/steam turbine plants.

our competitors,” said Pommer.
This innovative approach paid off. Weingärtner received the order to deliver the machine forprocessing the turbine shaft destined for use in agas turbine power plant. From the time Weingärtner received the order, it had only 20 months todeliver the machine, a situation made all the morechallenging by the fact that there was only one
high-tensile steel blank, worth $200,000, available
to make the prototype.
Weingärtner regarded selecting the right tooling supplier as critical to optimizing the machine’spotential. From the original six potential suppliers invited to carry out simple milling tests, inthe second phase, two were invited to produce

Milling cutters were developed for Weingärtner by Cutting Solutions
by Ceratizit, for machining the dovetail grooves of turbine shafts that
ensure precision positioning of the guide blade.

special tools that were tested in-house on thempmc 1200. Both models represent an identicalmachining concept. The results were evaluatedusing a matrix with the most important criteria

The resulting mpmc 2000S-7000 machining center has afor selection met by Ceratizit. “Cutting Solutions by Ceratizit

2-m swing diameter over bed and carriage, maximum turning

convinced us with their productivity, process security andlength of 7 m, and is able to completely machine workpieces

dimensional accuracy,” said Pommer. By December 2014,

weighing up to 80 t. This unit has a 72-kW main spindle, aWeingärtner had selected Ceratizit as its partner for develop-72-kW 3000-rpm turn milling head, and a 25-kW 6000-rpm

ing and delivering the tooling.

high-speed milling head.

“For the milling tests we used the Silverstar from the new

Weingärtner’s first meeting with its American customer tookgrade. We were very confident that we would obtain out-

place at EMO in September 2013. By that time, the company

standing results using the CTPP235 grade for this material

had already spent two years researching and engineering agroup,” said Peter Uttenthaler, Ceratizit area sales manager

machining center concept for complete machining of thesefor North America. “Other important tools included the ex-turbine shafts featuring an innovative component geometry.

tremely precise solid-carbide profile milling cutters for multiple

SHOP SOLUTIONS
cutting edges for the finish milling of the dovetail grooves; theinto individual work packages and planned and worked throughMaxiDrill 900 insert drill for deep holes with a diameter up toeach, step by step. Creativity backed up by engineering was

70 mm; and the HX parting and grooving system for largevital.” In Pommer’s opinion, Ceratizit’s Hofegger was one ofparting and grooving widths with maximum stability.

the key players in the project thanks to his excellent technical“Each of these tools contributes to the excellent eco-advice. Both sides are proud of the fact that the result ultimately

nomic efficiency of the overall process,” said Alfred Hofeg-

has even exceeded expectations. The overall machining time forger, head of Ceratizit’s OEM services, who was in charge

the large shaft including tool changes is only around 130 hours.

as project leader. “The milling concept ensures high pro-

Originally the goal was to reduce the machining costs by half. In

ductivity and thus short machining times. The solid-carbide

fact, they were reduced by two thirds.

profile milling cutters deliver excellent tool lifeand dimensional accuracy, and the HX parting and grooving systems also feature good
chip control combined with relatively low
cutting forces,” said Hofegger.
“You can say that in this machining center we apply tools which satisfy maximum
demands but all together cost less than thetools used until now for similar tasks,” said
Weingärtner’s Pommer.
Another important consideration withregard to the choice of the supplier was availability of cutting tools that would satisfy thecustomer’s requirements based on a rolling
forecast. Ceratizit maintains its own logistics
centers in Kempten, Germany, and throughits US subsidiary in Warren, MI. “It was also
considered a positive fact that we were able

Weingärtner’s scaled up mpmc 2000S-7000 is capable of machining workpieces
with diameters up to 2 m and weighing 80 t for applications in the oil and gas,energy, pump, aerospace, and general engineering markets.

to organize the regrinding of the tools in the US through ourAccording to Dominik Weingärtner, vice president of theCalifornia affiliate, Promax Tools,” said Ceratizit’s Uttenthaler.

family-owned company, both Austrian companies with an

According to Weingärtner, another advantage and evi-

extremely high share of exports, were able to demonstratedence of the commitment of everybody involved was that

how working together they are strong partners for demand-

the American Ceratizit employee responsible for the projecting customers around the world. “Culturally speaking, it

spent two weeks in Kirchham at Weingärtner’s headquarters

makes things easier when two Austrians communicate within order to become acquainted with the component, theeach other. We can really be proud of the technology thattools that are used, and the machining parameters.

comes from our region and it’s very likely that more will be“What we have achieved here is the result of a great teamperformance,” said Uttenthaler, “emphasizing how closely
both parties, Weingärtner and Ceratizit, worked together.
“The task was extremely demanding considering the tighttimeframe we had been given, said Pommer. “We broke it down

ENGINEERINGMARCH 2017

heard coming from team Weingärtner and Cutting Solutions
by Ceratizit in the future.”
For more information from Weingärtner Maschinenbau,
go to www.Weingartner.com; from Ceratizit USA, go towww.ceratizit.com, or phone 586-759-2280.

Copyright Notice: 2017 Copyright by Society of Manufacturing Engineers.
All rights retained. This article appears with permission fromManufacturing Engineering, the official publication of SME.