Looking at the M30 Millturn, a Longtime Favorite

(WFL Millturn Technologies: Linz, Austria) -- The classic Millturn complete machining center ushered in a completely new era in its original version more than 25 years ago. It was the first WFL Millturn with an individual tool carrier for turning, drilling, and milling with a B axis.

Many of these old M30 machines are still in use and delivering top performance, even after many years—so we decided to take a closer look at one of these “proto” Millturns.

Although the details of the current design have very little in common with its original version, the stable 60° slant bed is still there. Noteworthy features include the powerful headstock with 37 kW main drive and 2-speed gearbox as well as external C axis. Although the design dates back to the earlier Voest-Alpine WNC slant-bed machines, it is still used in the latest Millturn models of the M35, M40, and M50 series with modernized drive motors. Water-cooled direct drives are available as alternatives.

The first machines in the M30 series still had a 24-space magazine with automatic tool changer permanently mounted on the milling unit. Soon this magazine was replaced by an external magazine over the left-hand headstock that was much easier to operate and had an initial capacity of 48 tool stations (a lot back then). This made setting up the tools parallel to machining time possible for the first time. Capacity was then expanded to up to 96 tool stations. Due to the higher power and stricter stability requirements, the system size had to be increased to HSK63 or Capto C6 for current models.

The Siemens Sinumerik 880T was initially used as the control system for the first machines. Data memories of this control system were still in EPROM form, writable and erasable only with a special device. The newer machines were then delivered with the Sinumerik 840 C, which already had a hard drive for data storage.

Depending on the configuration, the machine had up to nine NC machining axes and was even capable of performing 5-axis interpolations. However, due to the lack of corresponding software solutions for the programming, this was a difficult and laborious undertaking. Thanks to the B-axis with 7.5 kW milling drive and 4,000 rpm, complex and highly precise oblique machining was possible with high productivity.

The modern M30 (left) and its ancestor

At the time, a new feature was a compressor cooling unit to stabilize the temperature of the turning-boring-milling unit. However, heat from the high continuous speeds was the Achilles’ heel of the turning-boring-milling unit; permanent grease lubrication was simply not sufficient. It was only with the newer models—which featured oil mist lubrication—that this problem was solved.

When it came to turning, the machines were unbeatable and were used in aerospace and automotive sectors, for hydraulic components, in mechanical engineering, manufacture, and medical technology for complex precision parts made from difficult-to-machine materials.

Today’s models still benefit from the experience gained from serving customers’ requests for decades. Ultimately, the machine is the means for exploiting all technological possibilities to the maximum. Then, as now, technological innovations require a solid foundation.

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