Grinding Machine Model

Studer S31
Universal Cylindrical Grinder with Up to 3 (2-external, 1-internal)Grinding Wheels

Studer S31 Universal Cylindrical Grinding Machine
Studer S31  
Studer S31 -

The S31 is designed for the grinding of workpieces in individual as well as small and large series production operations. It can be automated and is - thanks to its universality - especially suitable for use in the tooling and aerospace sectors, for example.
Centre height 175 mm (6.9"), Centre distance 1000mm (39.4")



  • Distance between centres of 650 (25.6") or 1000 mm (39.4") 
  • Revolving wheelhead that can be swivelled manually or automatically 
  • High-resolution B axis 
  • Frequency-controlled motor grinding spindle for external and internal grinding 
  • C-axis for the workhead for form and thread grinding 
  • Selection of several workhead models available for different grinding jobs 
  • Full enclosure with 2 sliding doors 
  • Machine base made of Granitan 
  • Standardised interface for loader and peripheral devices 
  • Extensive range of accessories  


Grinding length


Center height


Workpiece weight

176/264 lbs.

Swivel range wheelhead

-15 to +195°

Grinding wheel dimensions

20" x 3"

Spindle drive

10 hp

Studer S31cnc Universal Cylindrical Grinder with ID and OD Grinding Spindles

S31 cnc Offers Large Capacity, Proven Precision and Flexibility
Modular design for quick setup and changeover, state-of-the-art digital control and drive systems and user-friendly step-by-step programming make the S31cnc a remarkably flexible solution to a wide variety of internal and external cylindrical grinding applications. Center height is 175 mm. Between-centers grinding length is 650 mm, or 1,000 mm. Wheel size: 500 mm x 63 mm x 203 mm. Chuck capacity between centers is 130 kg. A dual wheelhead arrangement presents two external grinding wheels for rough and finish grinding in the same setup. The two wheels are diagonally positioned and have independent, programmable spindle drive systems to fully optimize the grinding process. Another wheelhead configuration is left/right with internal grinding for universal applications which allows OD, face and ID grinding in one setup.

The universal turret wheelhead with optional B-axis (fine adjustment to 0.0001 degree) swivels automatically, permitting external, internal and face grinding of workpieces in a single setup. A serrated 1 degree resolution Hirth ring coupling automatically maintains orientation from -15 degrees to +195 degrees, thus providing extreme accuracy and repeatability for grinding even the smallest tapered angles. An optional C-axis permits ultra-precise form grinding routines for tooling (punches, for example) and thread grinding.
S31cnc overview
Digital direct-drive, three-phase servo motors with 40-mm diameter prestressed, precision ballscrews power the X- and Z-axes Cross slide X-axis travel is 254 mm at speeds ranging to 5,000 mm/min. Linear resolution is 0.0001 mm. Distance between slideways is 280 mm. Z-axis slide travel is 800 mm/26" CD or 1,150 mm/45.3" CD. Speed and linear resolution are respectively 10,000 mm/min and 0.0001 mm. Z-axis distance between slideways is 200 mm. V and flat guideways are coated with abrasion-proof Granitan S200 and provide high vibration dampening and superior rigidity. Patented guideway design prevents hydrodynamic effects found in conventional guideways and results in high load-bearing over the entire machine speed range. The machine base of Studer-developed Granitan S103 delivers outstanding vibration dampening, rigidity and strength, as well as excellent chemical stability and thermal compensation. Grinding spindles are powered by two 7.5 kW motor and have high-precision roller bearings for precise, high-resistance, maintenance-free operation. Peripheral speed up to 50 m/sec with continuous speed control to 3200 RPM. Workpiece spindle, with high-precision roller bearings, handles grinding between dead centers as well as live grinding with revolving spindle. Precision control permits fine adjustment of cylindricity during grinding operations to +/- 40 �m. Guaranteed tolerance precision: 0.0004 mm on roundness and 0.0025 mm straightness deviation over a length of 650 mm (straightness deviation of 1,000 mm).

Wheel dressing intervals may be made by the operator following these simple methods: by pressing a pushbutton at any time during any grinding cycle; after a programmed number of specific machined parts or grinding operations; at programmed switchover points; at the programmed nominal size; after a specific number of strokes - or a combination of these, permitting the optimum solution for the specific grinding application. Grinding wheel reference points are referred to as "T" numbers, and together with Studer grinding cycles, "T" numbers permit programming with nominal size. The actual value indication on the control LCD refers in each case to the programmed wheel reference point. Values of the grinding wheel shape are entered in a dressing dialog display at the control.

Control & programming
The S31cnc features state-of-the-art Fanuc 16i digital control and axis drive components - or optional Fanuc 21i, a more cost-effective solution for less demanding applications. Machine operation, setup, changeover, dressing and programming of even complex parts are easily accomplished through the innovative, step-by-step Studer Pictogramming which allows operators simply to connect grinding cycles to one another and add necessary numerical values. The control then generates the machine program automatically. Advanced manual programming in G code is of course also possible. Programming is done directly at the machine or off-line and then downloaded to the machine control. Process parameters can be changed on the fly, while the machine runs, without affecting the workpiece program. The S31cnc control package features proven application-specific Studer grinding cycles for diameters, shoulders (left and right), tapers (negative and positive), contours, forms and threads.

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Universal Cylindrical Grinder with Up to 3 (2-external, 1-internal)Grinding Wheels
Grinder Type: Cam Grinder, Cylindrical-ID, Cylindrical-OD, Cylindrical-Uni, Thread Grinder
Machine Opertaion: CNC
CNC Brand: Fanuc 16i
Grinding Length: 26.000 Inches Opt. 40.000 Length: 660.400 mm   Opt. 1016.000
OD Grinding Diameter(s) Max: 14.000 Max: 355.600 mm
Workload 176 lbs.   Opt. 264 lbs 80 kg.   Opt. 120 kg
Grinding Wheel Dia.: 20.000 Inches    Width: 3.000 Inches    Bore: 8.000 Inches    Dia.: 508.000 mm    Width: 76.200 mm    Bore: 203.200 mm   
Wheel Head Motor: 10.00 hp Motor: 7.50 kW   1,000 rpm  Opt: 3,200 rpm   Angle Adjustment: 210.000°
Travel Max Feed Rapid Rate
Longitudinal 31.496 Inches 800.000 mm .00004 - 394"/minute ipm .001 - 10,000mm/minute mm/min 394 ipm 10,000 mm/min
Cross 10.000 Inches 254.000 mm .00004 - 197"/minute ipm .001-5,000mm/minute mm/min 197 ipm 5,000 mm/min
Machine Length: 114 Inches 2,896 mm
Machine Width: 86 Inches 2,184 mm
Machine Height: 79 Inches 2,007 mm
Machine Weight: 9,900 lbs 4,500 kg
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