Onsrud FSG-77

The Onsrud FSG-77 is a purpose-built 5-axis composite machining center designed for high-precision machining of complex CFRP structures, aerospace tooling, and contoured composite assemblies that demand true simultaneous 5-axis motion. Unlike conventional 5-axis machining centers configured for metal, the FSG-77 is optimized end-to-end for the unique cutting dynamics of carbon fiber reinforced polymers — from its high-speed, low-torque spindle architecture to its composite-specific toolpath strategies and dedicated fiber dust containment systems.

The FSG-77 features a fixed-bridge structure with a motorized trunnion table providing A and C rotational axes, giving the spindle full 5-axis reach on complex curved composite components such as aircraft fuselage frames, inlet lips, radome mounts, and helicopter rotor blades. The trunnion table is designed with carbon fiber tooling compatibility in mind — vacuum clamping circuits are routed through the rotary table to maintain workholding even as the part tilts. The spindle head delivers up to 30,000 RPM, which combined with the appropriate router tooling produces clean, splinter-free cuts in woven CFRP, unidirectional tape layups, and hybrid metal-composite assemblies.

Onsrud's integration of Heidenhain TNC control with RTCP (Rotation Around Tool Center Point) functionality ensures that 5-axis toolpaths maintain the programmed tool-tip position regardless of rotational axis position — essential for maintaining dimensional accuracy on tapered aircraft skins and compound-curved structural surfaces. The machine's enclosed working envelope and negative-pressure dust extraction system meet OSHA and NIOSH guidelines for carbon fiber particulate containment in production environments.

The FSG-77 is deployed in aerospace primary structure shops, composite repair stations, and specialty tooling houses producing jigs, fixtures, and master models from machinable composite and syntactic foam billets. It is particularly valued for programs requiring AS9100-traceable part records, as the Heidenhain control logs full machining process data for quality documentation.