SCHNEIDER - Model SLG 120 -Excellent Grinding of Mid-sized Optics

Solid foundation

• In designing the SLG 120, special attention has been paid to make it a compact and robust grinding machine that can be seamlessly integrated in existing system environments.
• It features a stiff cast-iron base and kinematics with up to 5 axes and 3 spindles. The modern CNC control system together with the quality-defining AC-servo drive technique enable high precision lens processing. A passive damping system guarantees smooth running.
• Highly dynamic linear driven X- and Y-axes and extra rigid guiding systems allow for smooth and precise movements. As a result, potential noise, stemming from mid-frequency errors, is reduced.
• The SLG 120’s B-axis supports a wide variety of processing steps thanks to its great swivelrange of +/- 90 degrees.

Advanced spindle technology

• The SLG 120’s multi-spindle system offers high flexibility in configuration. Up to three independent tool spindles and one workpiece spindle provide the freedom to arrange the processes to the individual needs.
• The double-spindle technology enables rough grinding including centering and beveling on one spindle followed by fine grinding on the second spindle – all in one process cycle. This offers higher process flexibility, stability, and further increases productivity.
• The two direct driven tool spindles allows for rpms of up to 20,000 with high torque, ideal for grinding hard materials such as saphire or silicon.
• The basic version SLG 120 is perfect for the flexible production of small batch sizes.
• The aspheric version SLGA 120 allows to grind aspheres with an additional horizontal wheel grinding spindle. This way, very precise contour processing of aspherical lenses is guaranteed. The alternatives – wheel grinding and cup wheel grinding, as well as edge processing – provide the freedom to select the optimal manufacturing processes for convex and concave aspheres.

Automated processing
An optional robot loading system guarantees non-stop processing of small to large batches. This way, maximum cost-effectiveness is guaranteed.

In-process metrology
The consistent high performance and tight process control is accomplished with an integrated metrology package. It controls usage and balance behavior of the tools, measures the form accuracies of the different grinding steps and calculates the form corrections. The process control compensates for tool wear and process drift. This facilitates optimal control of the individual process steps.

• The CT Control automatically checks the center thickness and makes adjustments.
• The Tool Control recognizes the grinding tools with a compact and robust probe that assesses the touch point very precisely. Setup and correction times are reduced significantly.
• The Feed Control and its first touch technology reduce the air cutting time during the tool approach to a minimum – saving valuable process time. It also optimizes the process during grinding by adjusting the feed rate of the tool with respect to the cutting conditions.
• The Curve Control allows for the measurement and correction of the spherical geometry.
• The Balance Control (Option for horizontal spindle) allows to control and optimize the smooth run of the tools, resulting in significantly reduced subsurface damage.

In addition to the in-process metrology, the Geo Control is a CNC-controlled fine adjustment of the mutual positions of the workpiece and tool spindles to optimize the spherical quality and form error.

An optional confocal measurement system checks for form deviations of the surface geometry in-situ. Together, these comprehensive metrology options are capable of evaluating the lens topography in 2D and 3D right at the spot. No need to take out the lenses or use external devices. This saves valuable time.

The control systems provide in depth data via OPC-UA interface technology for subsequent evaluation. 

• Great range of application, highest quality
• Aspheric and freeform package with cup tool and wheel grinding (optional)
• Compact machine base for high rigidity and stability
• Choice of direct-driven high-speed air or all bearing spindle
• Different clamping diameters (Z6 vs. Z12)
• Automated tool clamping system
• Electronically adjustable Y-axis alignment
• Feed Control
• Intelligent analysis system with remote diagnostics

• max. working range ø standard (and restricted) spheres : 120 mm (200 mm)
• max. working range ø standard (and restricted) aspheres : 140 mm (200 mm)
• working range radius : 10 mm – flat
• number of axes : 5 (X, Y, Z, B, C)
• positioning and repeat accuracy : X-, Y-, Z-axis: +/– 0.001 mm
• positioning and repeat accuracy : B-, C-axis +/– 4"
• tool spindle connection : Z12 or Z6; HD25
• speed range grinding tool spindle : ball bearing - 20000 RPM
• workpiece spindle connection : HD25
• speed range workpiece spindle : 3500 RPM
• power consumption : 18 kVA avg.
• compressed air supply : min. 6 bar (87 psi)
• vacuum : min. -0.6 bar (8.7 psi)
• machine weight : approx. 2060 kg (4542 lb.)
• dimensions (width x depth x height) : approx. 1550 x 1700 x 1900 mm (62 x 67 x 75 inches)