GROB G650

The GROB G650 is a large-format 5-axis universal machining center that sits above the G600 in GROB's lineup, designed for shops needing to machine exceptionally large structural aerospace components, heavy mold cavities, and oversized energy-sector parts in a single setup. With X/Y/Z axis travels of 1,150 x 1,250 x 1,100 mm and a maximum workpiece weight of 1,500 kg, the G650 represents the upper boundary of GROB's standard 5-axis product range before transitioning to special-purpose gantry and portal machines. It is purpose-built for Tier 1 aerospace suppliers, large mold shops, and defense contractors that regularly push the limits of what smaller 5-axis machines can accommodate.

GROB's horizontal spindle architecture is the engineering centerpiece of the G650. The spindle axis is oriented horizontally — parallel to the Y-axis — rather than vertically as in most 5-axis machining centers. This orientation means chips generated during aggressive roughing passes fall away from the work zone under gravity, preventing chip re-cutting and heat buildup in deep cavities. In a machine of this scale, where roughing passes in aluminum or titanium can generate several kilograms of chips per hour, effective chip evacuation is not a convenience feature — it is a fundamental requirement for consistent accuracy and tool life. GROB's horizontal spindle design addresses this directly without requiring high-pressure coolant systems as the primary chip management strategy.

The standard spindle runs at 12,000 rpm through an HSK-A100 interface, with an 18,000 rpm option available for aluminum-intensive aerospace work. Continuous spindle power is 62 kW (83 hp) with over 600 Nm of peak torque — figures that reflect the G650's capability for sustained heavy roughing in titanium and Inconel. The A-axis swivels +45° to -195° while the B-axis provides full 360° continuous rotation. The 900 x 900 mm pallet provides a substantial clamping surface, and the pallet interface is designed for integration with GROB's PSS-G automated pallet storage system, enabling multi-pallet production cells with minimal operator intervention.

The machine structure uses GROB's thermally symmetric cast iron construction, with active thermal compensation through temperature sensors distributed throughout the machine body. This thermal management is critical for a machine operating at this scale — thermal gradients that would be minor positional errors on a small machine become significant accuracy issues on a 1,150 mm axis. GROB's approach of symmetric construction combined with active software compensation maintains positioning accuracy at ±0.005 mm even during extended production runs with significant heat generation from the spindle and drives. The Siemens Sinumerik 840D sl control handles 5-axis kinematics with GROB4Pilot providing a simplified operator interface.

New G650 machines are priced between $1,000,000 and $1,500,000 depending on spindle configuration, tool magazine size, and automation options. The standard tool magazine carries 100 tools in HSK-A100 format, expandable to 160 positions. At this price point, the G650 competes with the Makino a81nx, DMG Mori DMU 125 FD, and Hermle C 62 in the large 5-axis segment. GROB's horizontal spindle differentiates it from these vertical-spindle competitors, particularly for aerospace roughing applications where chip management and sustained torque are primary selection criteria.