GERMANY 04NC, Mechatronics and Industry 4.0

NC that began in institutes and at trade fairs (1948–1963)

Aachen goes to see America

In Germany, the first to take up NC were the universities. Herwart Opitz, who led the WZL (Laboratory for Machine Tools) at the Aachen technical university from 1936 to 1973, traveled often to the U.S. and knew of MIT's research; in 1952 he sent his assistant Helmut Hucks to MIT to study the newly built NC milling machine. In 1955 the WZL built a model of an NC machine and showed it to a small group at a meeting in Aachen^[2]. At the 8th Aachen Machine Tool Colloquium (AWK) in 1956, a conference Opitz had started in 1948, Milton C. Shaw of MIT and others presented NC, and it became the first occasion in West Germany where NC was discussed before a wide audience^[2][1]. Stromberger's institute at the Darmstadt technical university also reported in 1957 on a turret lathe converted to magnetic-tape control^[2].

The first NC machines: Paris 1959 and Hannover 1960

Electrical makers began developing NC controls in the late 1950s. Siemens started development at its Erlangen laboratory in 1957, and in January 1958 showed management a single-axis straight-line control built with relays^[2]. In 1960 it brought out a relay-based positioning and straight-line control as “Siemens-NC,” which Pittler fitted to its Piromat 23N turret lathe^[5].

The first machine tool makers to show NC machines were two companies in Baden-Württemberg. At the 6th European Machine Tool Exhibition in Paris in 1959, Heller of Nürtingen showed the SBR 32 turret drilling machine with its own relay-based NC, and Burkhardt & Weber of Reutlingen showed an NC machining center. The SBR 32 is regarded as West Germany's first NC machine tool^[2]. At the machine tool exhibition in Hannover the following year, in September 1960, 11 West German companies exhibited NC machines. Siemens-Schuckert supplied the controls for four, and RWTH Aachen, BBC, SEL and AEG one each; nearly all were relay-based positioning and straight-line controls (moving to a set position and then cutting, or moving straight along one axis at a time). Only AEG showed a transistorized contouring control that interpolated straight lines and arcs, fitted to a Waldrich Siegen roll lathe^[2].

Why German NC got a late start

In the U.S., NC was developed with Air Force money for aircraft parts. West Germany had no such backing; in the postwar recovery orders were overflowing, and factories made parts in medium to large batches on newly installed conventional machines. In 1962, 75% of West Germany's roughly 470 machine tool makers had 250 or fewer employees, only about one in ten could pay for NC development itself, and only a handful were actually building NC machines. The NC control made up more than 30% of the machine's price, so the smaller the machine, the less it paid^[2]. On the other hand, the scale maker Heidenhain had brought out a measuring device that read its scale optically in 1952, and in 1961 the photoelectric rotary encoder ROD 1 (10,000 lines per revolution) and the linear scale LID 1, so the components for measuring position accurately were growing up inside Germany^[3][2]. Heller developed an NC milling machine and a machining center with ATC in 1962^[6].

Positioning/straight-line control and contouring control. A drilling or boring machine only needs to move quickly to a set position, stop and drill the hole there (positioning). To cut angled faces or arcs on a milling machine, two or more axes must be moved at the same time while the ratio of their speeds is computed and changed (interpolation) (contouring control). Early NC built with relays could do only the former; contouring control needed electronic circuits. Because tapers and radii on a lathe also need contouring control, NC lathes did not spread until contouring control became cheaper in the mid-1960s.

SINUMERIK and EXAPT (1964–1974)

The SINUMERIK name

At the September 1964 machine tool exhibition in Hannover, Siemens gave its NC the name “SINUMERIK” and switched its circuits from relays to transistors. The following year, 1965, it brought out its first contouring controls, the Sinumerik BG (closed loop with servo motor and position sensor) and BO (open loop with pulse motor)^[2][5]. In the autumn of the same year, 1965, Siemens signed a contract with Japan's Fujitsu and began building and selling Fanuc's electro-hydraulic pulse motor (a feed unit that boosts the force of a small motor, turned by electric pulses, with hydraulics). It was an inexpensive NC combination that did without a position sensor^[2]. At the 1967 European Machine Tool Exhibition in Hannover, the Fanuc 260 stood in the Siemens display^[2].

Open loop and closed loop. An open-loop NC simply commands “move so many pulses” and does not check whether the slide actually got there. As long as the pulse motor does not lose steps (fail to keep up with the command and miss turns), it is cheap and accurate, but it does not suit heavy or fast feeds. A closed-loop NC measures the motor's rotation or the table's position with a sensor and cancels any difference from the command with a servo motor. It costs more, but even heavy machines can be moved quickly and accurately. Early NC used the two according to the balance with price, and as sensors became cheaper and better, closed loop became the norm.

What spread the NC lathe in one stroke was GE's inexpensive contouring control, the GE 100S, from the U.S. At an exhibition in Brussels in 1965, the lathe maker Heyligenstaedt is said to have taken orders for more than 100 NC lathes with the GE 100S^[2]. Boehringer of VDF showed its first NC lathe in 1964, but straight-line control did not suit a lathe, and it began to sell only from 1967, when it switched to contouring control^[2]. Gildemeister of Bielefeld also showed its first NC lathe, the RSA, in 1965 and put it on sale in 1967^[7]. In 1968 Bosch bought the small NC control maker Dr. Masing and began building contouring NC under license from the American company Bendix^[2].

EXAPT and the Opitz code

As NC spread, the work of writing programs became a problem. APT, the NC language created at MIT in the U.S., could describe shapes but could not decide cutting conditions such as spindle speed and feed by itself. So from 1964/65 the WZL in Aachen and TU Berlin (Simon, later Spur), joined from 1965 by Stute's institute in Stuttgart, created EXAPT (Extended APT), which added machining technology to APT. In 1967 the company-funded EXAPT-Verein was formed, with Siemens among its founders^[2][1]. The turning part (EXAPT 2) drew on the experience of Spur, who had been Gildemeister's head of design^[2]. In 1964 Opitz's research gave rise to the “Opitz code,” which expresses a part's shape as a string of digits; it spread worldwide as a basis of group technology, which makes similar parts together. It has also been translated into Japanese^[1].

Trumpf's TRUMATIC 20

Trumpf of Stuttgart was originally a maker of flexible-shaft tools and electric shears. Berthold Leibinger, who had worked on NC lathe design at Cincinnati in the U.S., became its head of design, and in 1967 it showed the TRUMATIC 20, a machine that punched sheet by tracing a template, now fitted with contouring NC, at the European Machine Tool Exhibition in Hannover. Even the tool change was automatic, and on paper-tape commands it could cut out any shape by punching a little at a time (nibbling)^[2][8]. This machine became the starting point of Trumpf, the later laser machine company (for details, see Chapter 9).

The year 1970 in numbers

From 1957 to 1970, West Germany built 2,861 NC machine tools worth 906 million marks. Of the 368 built in 1970, 302 were NC lathes with contouring control. In mid-1971, 53 companies were building NC machines, only about 12% of the total^[2]. At the 1970 exhibition in Hannover, Siemens demonstrated DNC (direct numerical control), linking 13 machine tools in the hall to one computer^[2], and in 1973 Siemens' first CNC (NC with a built-in computer), the Sinumerik 580, came out. AEG had brought out a CNC five years earlier^[2].

CNC and programming on the shop floor (1975–1989)

Siemens and Fanuc

In July 1975 Siemens and Fujitsu Fanuc (spun off from Fujitsu in 1972) signed a new contract to jointly develop NC controls. In Asia Fanuc would sell Sinumerik, in Europe Siemens would sell Fanuc, and for the U.S. they formed the joint venture General Numeric^[2]. The first result was the Sinumerik System 7 of 1976, which used a microprocessor based on the Intel 3000 with added NC instructions; the control became smaller and cheaper, and the machine's sequence control (PLC) was also brought into the CNC^[2][5]. The alliance ended in June 1987, after the Commission of the European Communities investigated the sales arrangements from 1982 and in 1986 fined both companies for closing off the market. Since then the two have competed in the world market^[2].

Heidenhain's TNC and Maho

The biggest change in German NC in this period was the idea of the operator writing the program at the machine. In 1976 Heidenhain, working with Maho of Pfronten, brought out the 3-axis NC TNC 110/120. It cost about a fifth of the NCs of the time, making it possible to put NC on the small milling machines of Maho and Deckel^[3][2]. Maho's first NC milling machine, the MH 900 NC shown at EMO Paris in 1975, did not sell, but machines fitted with Heidenhain's TNC succeeded from 1976–77; more than 6,000 were sold with the TNC 121 alone^[2]. From 1979/80 Heidenhain marketed a method of entering drawing dimensions by answering prompts, which it called “Klartext” (plain language), and in 1981 brought out the 3-axis contouring control TNC 145^[2][3]. Deckel of Munich teamed up with Grundig and in 1978 fitted an NC, “Dialog 1,” which guided operation on a small screen, to its tool milling machines^[2].

The same trend came to lathes. Gildemeister brought out its own CNC, “Elektropilot M,” in 1977^[7][2], and on its first CNC lathe in 1979 Traub loaded its own shop-floor programming software on top of an NC from Japan's Mitsubishi Electric^[2]. Siemens, too, brought out a CNC at EMO Hannover in 1977 that could command lathe contours briefly^[2].

What changed on the shop floor. Until then, NC assumed a division of labor: a “programmer” in the office made the paper tape, and the operator on the shop floor just watched over the machine. The TNC and conversational CNCs, which let operators key in programs at the machine while looking at the drawing, spread NC to small job shops and die shops with many orders for one or a few parts. The way of “setting up and programming at the machine,” taken for granted in Japan's small shops today, was born from the competition between German and Japanese NC in this period.

Laser machines

In 1979 Trumpf brought out the TRUMATIC 180 LASERPRESS, which combined punching and a 500 W CO2 laser in one machine. The laser lacked power and the start hole had to be made by punching, so the two were combined. 200 were sold in three years; in 1985 it brought out its own CO2 laser, the TLF 1000 (over 1 kW), and in 1987 the TRUMATIC L 3000, a laser machine in which the processing head moves instead of the sheet^[11][12][2].

Pushed aside by Japanese NC

In 1985, world shares of NC controls (excluding other small makers) were about 60% for Japan's FANUC, Mitsubishi Electric and Okuma, just under 15% for Germany's Siemens and Heidenhain, and 5.6% for GE of the U.S. Considering that in West Germany in 1970–74 GE had held 42% of NC lathe controls, the map had been redrawn in ten years^[2]. At EMO Hannover in 1989, Sercos, a standard for digital communication between NC and drives developed by several German companies, was announced^[2].

Restructuring and DMG MORI (1990–2010)

In the early 1990s, after the boom following reunification, the German machine tool industry fell into a deep slump and cut its workforce sharply. Researchers name as a major cause that machines had been over-engineered for each order, so they could no longer be made as cheaply as in Japan^[14]. Deckel of Munich and Maho of Pfronten signed a merger agreement in June 1993, but Deckel Maho AG collapsed in 1994, and Gildemeister of Bielefeld took over most of it. The Geretsried, Pfronten and Seebach works continued in the Gildemeister group^[2][14][7]. On the NC control side as well, Grundig bought a majority of Gildemeister's NC division in 1993, and in 1996 Heidenhain took over Grundig's NC division, so the NC lines of Deckel, Maho and Gildemeister came together at Heidenhain^[2].

In 1994 Siemens brought out the Sinumerik 840D, which connects digitally to the drives and lets machine makers add their own software; in 1996 it added Safety Integrated, which monitors safety functions in software, and in 1997 ShopMill and ShopTurn, which build up machining steps on the screen^[5][2]. Heidenhain's TNC reached a cumulative 100,000 units in 1996^[2]. Bosch's NC moved to Bosch Rexroth in 2001^[2].

Machine makers changed shape too. INDEX of Esslingen bought neighboring Traub in 1997^[16], and in 1994 EMAG brought out the VSC, a vertical pickup lathe whose spindle picks up the workpiece and carries it over the tools^[15] (for details, see Chapter 5). Hermle of Gosheim became a stock corporation and went public in 1990, and came to be known for 5-axis machining centers^[13]. Chiron of Tuttlingen (into machine tools from feed units in 1958) and Grob of Mindelheim (works in 1968, lines for automotive parts) also grew into mid-sized companies of southern Germany^[4][9] (for machining centers, see Chapter 6).

Measuring accuracy and correcting it electronically

The accuracy of NC depends on the rigidity of the machine and the accuracy of the scales that measure position. Heidenhain brought out a sealed linear scale that protects the graduation from dirt and cutting oil in 1966, and in 1987 a scale that reads even finer using light interference^[3]. If the table's position is measured directly with a scale on the table rather than from the motor's rotation, errors of the feed screw and thermal growth can be corrected too. At the universities, research on machine rigidity, vibration and thermal deformation continued; the WZL, for example, made machine tools a separate chair from 1973^[2]. Such research moved beyond building machines rigid and precise toward cancelling measured errors with NC.

Mori Seiki and DMG

In 2003 Japan's Mori Seiki began selling machines with Heidenhain CNCs in Europe. Then in March 2009 Mori Seiki and Germany's DMG (Gildemeister) began a business alliance, followed by a capital alliance. Jointly developed machines came in 2011, and the integration of European sales and service in 2012^[17]. In research on machine accuracy, too, the move to make up for machine errors electronically grew stronger; in 2008, for example, Siemens brought out “volumetric compensation,” which measures position errors of large machines and corrects them with NC, for large machines making aircraft parts^[2].

★Industry 4.0 and today (2011–)

At the Hannover Messe (trade fair) in April 2011, Henning Kagermann, Wolf-Dieter Lukas and Wolfgang Wahlster put forward the term “Industrie 4.0.” They called a factory in which machines and products are networked and products tell how they are to be made the “fourth industrial revolution,” following steam, electricity and computers^[2]. For machine tools, the problem was that each maker output machine data in its own way. At EMO Hannover in 2017, the VDW launched with 17 companies the common interface umati for connecting machines of any make in the same way, and at EMO 2019 demonstrated 110 machines from 70 companies connected together. The first official release came in 2020, and in September the first version of OPC UA for Machinery, a foundation for the whole machinery industry, was released^[2][19][18]. At EMO 2019 Siemens brought out the SINUMERIK ONE, which makes it easier to create a “digital twin” of the machine^[2].

What umati means on the shop floor. When machines from different makers stand side by side in a factory, collecting operating status, the program being run and alarms used to need a different connection and translation for each machine. Because umati defines, on top of the common communication standard OPC UA, that “this information is output under this name in this form,” compatible machines can be shown side by side on the same screen in the same form. It can be used to visualize machine utilization and for maintenance that catches early signs of wear in spindles and ball screws. In Japanese factories too, it is most effective on lines that mix imported and domestic machines.

At EMO Hannover in 2013 DMG MORI showed CELOS, its app system for the control panel; in October it unified its company names, and in August 2016 a domination and profit transfer agreement between the Japanese and German companies took effect, bringing them under unified management. In September 2020 it started up a monoBLOCK plant making 5-axis machines and more in Pfronten, Maho's former home town^[17].

Today the German machine tool industry, with about 65,000 employees and production of about €15 billion in 2024, ranks second in the world after China (about 13% share). It exports more than 70% of its output and is said to be the world's largest exporter^[20]. In Gardner's 2024 world survey from the U.S. too, production ranked China, Germany, Japan^[21] (for Japan's figures, see History in numbers).

Links with Japan

• Electro-hydraulic pulse motor (1965). The electro-hydraulic pulse motor of Fanuc that Siemens built and sold is the same type that was used in “Japan's first NC vertical lathe,” shown at the 1st Japan International Machine Tool Fair (today's JIMTOF) in 1962 (Japanese Archive, Chapter 1)^[2].
• Siemens and Fanuc (1965–1987). Through licensing, sales and joint development (System 7) they worked together for more than 20 years, then parted in 1987 and became competitors^[2]. In a flow of technology in the other direction, FANUC brought out an automatic wire threader for wire EDM in 1979 using Siemens technology (Japanese Archive Chapter 6).
• NC control shares (1985). About 60% for three Japanese companies, just under 15% for two German ones. The German lathe maker Traub used a Mitsubishi Electric NC on its first CNC lathe in 1979^[2].
• The Opitz code (1964). It was translated into Japanese as a method for classifying parts^[1].
• Trumpf's and Heidenhain's Japanese subsidiaries. Trumpf set up a subsidiary in Yokohama in 1977 (still a competitor of Japanese sheet metal machine makers)^[8][2], and Heidenhain set up a Japanese subsidiary in 1980^[3].
• DMG MORI (2009–). From the alliance between Mori Seiki and Gildemeister came a single German–Japanese group. Mori Seiki's history is in Japanese Archive, Chapter 1, Chapter 2, Chapter 7^[17].
• Trade shows. EMO (Hannover, Milano) and JIMTOF (Tokyo) are also where Japanese makers show new machines. Japanese multitasking machines appeared at EMO Paris in 1983 (Chapter 7).

FAQ

What was the first NC machine tool in Germany?

A University of Stuttgart doctoral thesis (2023) calls the SBR 32 turret drilling machine, with Heller's own relay-based NC, which Heller of Nürtingen showed at the European Machine Tool Exhibition in Paris in 1959, “probably West Germany's first NC machine.” An NC machining center by Burkhardt & Weber was also at the same exhibition. You may also see it stated that Schiess brought out an NC machine in 1957, but this does not match the company's 100-year history and is unsupported.

When did the SINUMERIK name begin?

Siemens brought out a relay-based NC as “Siemens-NC” in 1960, and at the September 1964 machine tool exhibition in Hannover it gave the name “SINUMERIK” to its NC, now with transistor circuits (according to Siemens' internal chronology). Some articles write SINUMERIK from 1960.

What was new about Heidenhain's TNC?

The TNC 110/120 of 1976 was an NC built to suit Maho's milling machines, and it cost about a fifth of the NCs of the time. It was designed so the operator could key in drawing dimensions at the machine, and it grew into the conversational programming later called “Klartext.” It was the device that spread NC to small milling machines and to shops with many orders for one or a few parts.

Is DMG MORI a German company or a Japanese company?

It is one group that carries both lines. Germany's Gildemeister (which took over Deckel Maho in 1994) and Japan's Mori Seiki formed an alliance in 2009, unified their company names in 2013, and in 2016 a domination and profit transfer agreement between Japan's DMG MORI and Germany's DMG MORI AG took effect, bringing them under unified management. It has plants in Bielefeld, Pfronten and elsewhere in Germany and in Iga, Nara and elsewhere in Japan.