«Superfast swiveling times»
For every internal cylindrical grinding application STUDER has the optimal machine – primarily for
use in machine tools and toolmaking as well as for the aerospace and automotive industry. The
focus is on machining small to medium sized parts: Die plates, spring collets, tool holding fixtures,
hydraulic components, medical components, thread ring gauges and many other workpieces made
from tool steel, tungsten carbide, ceramic and glass. One of these all-rounders is the CT960 with
four spindles and a fully interpolating B-axis – a complete universal internal cylindrical and die plate
grinding machine with external grinding options. This year Fritz Studer AG has further developed
the CT960 at its center of excellence for internal cylindrical grinding in Biel. The completely
overhauled grinding spindle turret now has a highly dynamic direct drive. «This will enable
superfast swiveling times in thefuture», emphasizes Michel Rottet, Internal Grinding Product
Manager at STUDER.

Infinitely variable angular position in four ranges
The new turret with direct drive is a very important component for complete machining. It enables
the use of up to four grinding spindles and a measuring probe. This allows complete machining of
workpieces in the same clamping as well as process-based measurement – with minimal auxiliary
times combined with greater precision. The swiveling time for 90° is < 2 seconds, for 270° < 3
seconds. The angular position of the grinding spindles is infinitely variable from –5° to +30° in all
four positions. The functions previously executed by means of mechanical indexing are now
undertaken by the StuderSimCT software.

Fast and wear-free B-axis
The decisive innovation of the CT960 lies in the automatic B-axis of the workhead with a swiveling
range of +61° to -91° and a direct drive, which enables very fast and precise positioning as well as
very precise grinding with interpolation of the B-axis for grinding radii. Thanks to the new design
the B-axis now has no contact surface, is completely closed and consequently wear-free and
moves even faster. With its precision of < 1/10,000° the machine is in the range of the barely
measurable.

Details for even greater precision
However, details are also important for achieving optimal grinding results. And these have certainly
been taken into account in the improvements to the CT960: On the one hand a new coolant
distributor ensures well-regulated internal conditions, while on the other hand the machine base,
comprising GGG60 casting, has been overhauled. The new shape and resulting higher rigidity
have a positive effect on the entire axis system. An easy-cutting grinding wheel is essential for
cost-effective and high-quality grinding. The dressing unit in the base pedestal of the CT960 has
therefore also been re-designed, and the dresser has been reinforced with a new stop – for even
greater precision during grinding wheel dressing.