ELB-Schliff SW 6 Series

Spark-out is the final phase of a surface grinding cycle where the wheel continues traversing the workpiece without additional downfeed after the last programmed depth pass. During spark-out, the machine grinds away residual deflection (spring-back) in the workpiece and machine structure that accumulated during the cutting passes. Without spark-out, the finished surface would be slightly higher than the programmed dimension due to elastic deflection. Spark-out passes are programmed on the ELB SW 6 via the Siemens 828D cycle setup — typically 2–5 passes are used depending on material and required flatness tolerance.

The SW 6 accepts standard surface grinding wheels with a maximum 400 mm outer diameter and 50 mm width. Typical wheel specifications for the machine range from A46-K (aluminum oxide, 46 grit, K bond — general steel grinding) for roughing to A120-J (fine grit) for finishing. CBN grinding wheels for hardened steel and ceramic-bonded wheels for high surface finish are also compatible at appropriate spindle speeds. Wheel selection depends on the workpiece material and required surface finish — ELB-Schliff and wheel manufacturers (Saint-Gobain Abrasives, 3M, Noritake) can advise on optimal wheel specification.

The SW 6 series can perform basic profile grinding using CNC-controlled wheel dressing to produce formed wheel profiles, then grinding the workpiece with the profiled wheel. For complex profile grinding with simultaneous multi-axis contouring, ELB offers profile grinding variants (SW Profile series) with additional CNC axes for 2D contour dressing and grinding. The standard SW 6 is optimized for flat and form surface grinding rather than continuous path 2D profile grinding like CNC cylindrical profile grinders.

The electromagnetic (EM) chuck uses electrically generated magnetic flux to hold ferromagnetic workpieces (carbon steel, tool steel, cast iron) directly on the chuck surface without mechanical clamping. When energized, the EM chuck holds parts firmly against grinding forces. Demagnetize the chuck after grinding to release parts and prevent residual magnetism that could affect downstream assembly. Non-ferromagnetic materials (aluminum, stainless steel, titanium, carbide) cannot be held by EM chucks — use mechanical clamping, sine plates, or dedicated fixtures for these materials.

Surface grinding uses water-soluble coolant (metalworking fluid) delivered to the grinding zone at high flow rate (typically 20–50 L/min through a flood nozzle positioned at the wheel-work interface). Recommended coolant concentration is 4–6% for general grinding of steel and cast iron. Coolant removes heat from the grinding zone — insufficient coolant causes thermal damage (burning), residual stress, and dimensional instability. The SW 6's 200 L coolant tank includes filtration to remove ground swarf. For CBN wheel grinding, use specific coolant formulations recommended by the wheel manufacturer.