Success Story

FOG machining center: Used by global market leader

High tech on the piste - Getting safely to the top - cut by cut

Prototype on 2000 piles 

For over a century, Droop+Rein has been making a positive contribution to mobility. Machining centres from Bielefeld are used to produce drives for submarines, ship motors and aircraft landing gears. However, a milling head from the FOG series is involved in one of the most unusual applications on a daily basis on Lake Constance. It is used to produce segments for pulley wheels for the global market leader in cable car construction. 

"If we're talking about Droop+Rein, we'd certainly consider buying a second one". That's the short assessment of Karl-Heinz Zündel, Head of Production at Doppelmayr Seilbahnen GmbH from Wolfurt (Austria), and shows the company's satisfaction with the FOGS D40. It was made by Bielefeld-based Droop+Rein, a brand belonging to Dörries Scharmann Technologie GmbH (a subsidiary of the Swiss Starrag Group). The Austrian cable car manufacturer was impressed on a visit to German company Liebherr-Aerospace Lindenberg GmbH in Allgäu, where three machines from the same series manufacture landing gear components for aircraft. Zündel and his department manager, Klaus Meyer, particularly like the gantry concept. 

For its specific application - turning, milling and drilling up to 13 meter segments for pulley wheels (drive wheels) - Doppelmayr ordered a larger, open unit of the FOGS D40 type with two working areas, something that Droop+Rein had never before produced in this type and size (20,000 mm x 9,400 mm x 6,900 mm). The travel distances on the multifunctional machining centre are 12,000 mm (X-axis), 4,000 mm (Y-axis) and 2,000 mm (Z-axis), with a travel angle of ± 200° (controlled C-axis). The machine table for the 135 ton unit measures 4,000 mm x 12,850 mm, while the rotary table has a diameter of 3,000 mm and is powered by two 60 kW AC motors. 

Machines from the FOGS D40 series have a mechanical main drive with fork-type milling head and cartridge to hold the motor and gear spindles. The milling unit is made up of the cross slide, which can be moved in the Y-axis, and the fork head attached to the 40 kW slide feed milling unit (Z-axis, max. 6,000 rpm), which has an integrated C-axis. Doppelmayr had the machine fitted with an eccentric fork-type milling head along with an angled and a vertical milling head (each with 40 kW of power). 

"We needed a significantly larger open machine with a travelling column design", says Zündel. "Because there was nothing like that available, we took the risk and bought a new development. It was also important for me that the machine would be valued by the people who work on it." Another reason why the machine is very popular with him and his staff is that its open design allows it to be cleaned easily with the integrated high pressure hose. Doppelmayr improved the ergonomics by installing foundation connection plates and cooling lubricant return channels.

In 2009, the Bielefeld company produced the prototype at the Hohe Brücke plant, which stands on 2000 piles due to the marshy ground. Since then, the innovative German solution has been cutting segments from solid, extremely hard to cut structural steel, with four elements plus the central section making up the pulley wheel. At the rear of the plant are the large heavy-duty cutting machines, which must not influence one another even when running flat out. A U-shaped foundation is used for the FOG series, offering excellent rigidity and having a lower depth than other types of foundation. This construction makes assembly easier, cuts costs and also has a positive impact on the "tool life". Department manager Klaus Meyer says: "The rigidity of the machine is a hugely important factor for us. The side milling cutters have an incredibly long service life."


The various components have to be machined with 20 to 25 µm precision in a single clamping. "We are very satisfied with the reliability and availability", the department manager said. An annual volume of 800 segments produces around 200 pulley wheels in different dimensions. Thanks to the rapid head replacement, the setup times - for changing from rough to fine machining for example - are relatively short. Workers on the FOGS D40 do not usually utilise the full length. They generally set up the next component in a partitioned area of the machine while another segment is being machined. 

The exception is when very large components are being machined. For example, the Hohe Brücke plant produces segments for the "giant wheels" in the valley station of the Galzigbahn cable car in St. Anton at the Arlberg, whose diameter of nine metres is surely a record, not just for Doppelmayr. But the machine can cope with even these huge components. Meyer says: "If we remove the partition wall for setting up, we can handle components up to a length of 13 metres". 

Doppelmayr Seilbahnen GmbH, Wolfurt (Austria) 

The Doppelmayr Group (around 2400 employees, turnover 795 million Euro in 2012/2013) is the global market leader in cable car construction. To date, the Group has built over 14,400 cable car systems for customers in 88 nations. Other than cable cars of all kinds, the Group also produces miniature and material supply railways, high bay warehouse systems, car parking systems, long distance continuous conveyors and Cable Liner passenger systems.

Galzigbahn in St. Anton

The cabins are raised to a height of 2100 m over a distance of 2.5 km more quickly and with less vibration than previously on two parallel cable lines. The Galzigbahn can transport up to 2200 people per hour to a snow-sure altitude of almost 2100 metres. Doppelmayr has combined what is known as a funitel system with a world first: When the cabins reach the valley station, they are transferred onto two "giant wheels" and lowered by around 8 m. Thanks to this giant wheel concept, passengers can conveniently get on and off from level ground with no steps. The building was designed by Tyrolean architect Georg Driendl and has a glass façade, which means that the drive concept can be seen by day and - thanks to lighting - at night. 

Technical data for FOGS 30 120 TT DT D40 C

X-axis (longitudinal cross beam)

13,000 mm
(for each working area: 6,000 mm/6,000 mm or 8,000 mm/4,000 mm) 

Y-axis (lateral cross slide)

4,500 mm (2,250 from centre to left/right respectively)

(vertical milling slide)

2,000 mm

A-axis (rotary table)

n x 360°/ Ø 3,000 mm

C-axis (continuous milling head rotation)


Max. load (rotary table)

25,000 kg


40 kW (S1)

Torque (turning, drilling/milling)

1100 - 1800 Nm (S1)

Max. spindle speed

6,000 rpm (S1)

Tool changer type

Chain magazine for 120 tools


Milling head changer for 3 heads

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