Linear servo-stroking technology Sunnen SV-20 produces quality automotive bore geometry

According to Sunnen, the SV-20 is a breakthrough design featuring computer-controlled spindle and stroke control developed for race shops, production rebuilders and fleet maintenance facilities. The machine accepts blocks as large as the Cat 3126 in-line six and Ford 7.3 L V-8 (International 444) – even 'mountain motors' with deck plates can be honed in one set-up on the rollover fixture. The SV-20 is equipped with a variable speed 15 to 600 rpm, 4.1kW spindle motor, powerful enough to drive two-stage diamond honing tools through a 20-inch stroke at up to 100 strokes per minute. The large multi-stone tools produce a rounder bore than possible before. The SV-20's linear stroking system with 2.5 kW servo drive keeps the honing tool concentric with the bore throughout the full stroke length to produce a consistent diameter from top to bottom of the bore. It can hone bores with inside diameters from 19 to 200 mm. The front-loading machine's 915 by 1,015 mm work envelope and 680 kg weight capacity mean that it can process a wide range of other large parts, such as compressor bodies and pumps. The PLC-controlled SV-20 uses an industrial colour touch screen with hand wheel to jog for fast set-up and easy operator training. The computer control ensures automatic, consistent bore-to-bore geometry and finish, without constant adjustment by the operator. The control's real-time display of bore cross section allows the user to see taper and correct it by dwelling the tool in the required position. Programmable auto dwell also allows taper correction through the PLC for unattended operation. The control also allows on-the-fly changes of spindle and stroke speeds, and automatic calculation of crosshatch, stroke length/speed and spindle speed. Variable speed control provides a wide range of processing options and consistent crosshatch pattern, with automatic switching from roughing to finishing with one push of a button. Left/right positioning of the column on its 760 mm X-axis is accomplished with a machine-mounted hand wheel immediately below the PLC. The machine comes standard with a 208 litre internal coolant system equipped with two standard canister filters. The SV-20's rotary servo tool feed system can be used with two-stage hone heads to complete roughing and finishing without stone changes for faster processing times. The machine is compatible with Sunnen's past and current tooling for CK/CV/SV-series machines, including diamond abrasive hone heads and brushes, GHSS single-stage hone heads with CBN or diamond abrasives and brushes, and GHTS hone heads for two-stage honing with CBN or diamond abrasives. The SV-20 is available with a 400V/50Hz/3Ph or 460V/60Hz/3Ph electrical system. Options include a T-slot base and manual rollover cradle for engine blocks.