Grob G550T
Key Specifications
X Travel
Y Travel
Z Travel
Max Spindle
Spindle Taper
Tool Capacity
Overview
The Grob G550T extends the G550 5-axis machining center platform with full turning capability, creating a mill-turn machine that performs complete machining of rotational and prismatic components in a single setup. The T designation adds a high-torque turning mode to the C-axis workpiece table, enabling the G550T to turn, mill, drill, bore, and 5-axis contour mill without removing the workpiece. This single-setup capability is the defining value proposition for complex components combining turned and milled features, such as aerospace blisks, turbine shafts, and complex valve bodies.
Grob horizontal spindle kinematics adapt naturally to turning operations. With the workpiece rotating on the C-axis, the horizontal milling spindle presents the turning tool at the workpiece, and the tilting B-axis enables compound-angle turning operations that are not possible on conventional vertical mill-turn machines. Simultaneous 5-axis milling of non-rotational features can be performed during or between turning operations, all in a single clamping.
The machine retains the G550 HSK-A63 milling spindle at up to 24,000 RPM for milling operations and adds high-torque drive to the C-axis table for turning. The 52 kW spindle provides both milling power for aggressive stock removal and cutting force for hard-turning of steel and stainless components. Parts up to 630 mm in diameter can be turned on the machine.
The G550T targets aerospace manufacturers machining blisks and turbine discs, medical device manufacturers producing complex orthopedic implants, and power generation and oil and gas manufacturers producing complex valve and pump components where the cost of multiple machine setups and inter-machine transportation is prohibitive.
Full Specifications
| Parameter | Value |
|---|---|
| X-Axis Travel | 630 mm (24.8 in) |
| Y-Axis Travel | 500 mm (19.7 in) |
| Z-Axis Travel | 500 mm (19.7 in) |
| Max Spindle Speed | 17,500 RPM (24,000 RPM optional) |
| Spindle Taper | HSK-A63 |
| Spindle Motor Power | 52 kW (69.7 hp) |
| Spindle Torque | 210 Nm (milling) |
| Table Diameter | 630 mm (24.8 in) |
| Table Load Capacity | 600 kg (1,323 lb) |
| Turning Diameter Max | 630 mm (24.8 in) |
| C Axis Speed | 800 RPM (turning mode) |
| Rapid Traverse Rate | 60 m/min (2,362 ipm) |
| Tool Capacity | 60 (expandable to 240+) |
| Positioning Accuracy | < 0.005 mm (< 5 µm) |
| CNC Control | Siemens Sinumerik One / Fanuc 31i |
| Machine Weight | 19,500 kg (42,990 lb) |
Specifications sourced from grobgroup.com — verified 2026-03-28
Strengths & Limitations
Strengths
- Complete mill-turn capability in a single setup eliminates inter-machine handling and re-fixturing error for complex rotational components with significant milled features
- Horizontal spindle concept enables compound-angle turning operations not possible on conventional vertical mill-turn machines
- 52 kW spindle provides both milling power for aggressive stock removal and sufficient cutting force for hard-turning of steel and stainless workpieces
- Simultaneous 5-axis milling of non-rotational features during or after turning in a single clamping, critical for blisks and complex valve bodies
Limitations
- At $700K-$1M, the G550T requires complex parts and sufficient volume to justify versus investing in separate milling and turning machines
- Turning diameter is limited to 630 mm; large-diameter shafts and flanges need a dedicated turning center or larger mill-turn platform
- Programming complexity for mill-turn 5-axis simultaneous operations requires experienced CAM programmers and thorough simulation before first production run
Best For
Frequently Asked Questions
01
The G550 is a pure 5-axis milling machine. The G550T adds full turning capability by adding high-torque drive to the C-axis rotary table, enabling turning, milling, drilling, and 5-axis contouring in a single setup. The G550T is typically $150K-$300K more expensive than an equivalent G550 configuration.
02
Yes, blisk machining is one of the primary applications for the G550T. The machine can rough-turn the disc hub, then perform simultaneous 5-axis milling of the blade profiles, then finish-turn critical bore features, all in a single clamping. This eliminates inter-machine transfer errors that accumulate when these operations are performed on separate machines.
03
The G550T supports turning of parts up to 630 mm in diameter, limited by the table diameter. For turning, the workpiece is held in a chuck or on a faceplate mounted to the rotary table, and the milling spindle presents the turning tool at the appropriate orientation.
04
The Mazak Integrex and DMG Mori NTX are dedicated mill-turn machines with horizontal turning spindles and typically higher turning spindle power. The G550T is a 5-axis machining center with turning capability added, giving it an advantage in complex simultaneous 5-axis milling where the horizontal milling spindle kinematics provide better rigidity and chip evacuation.
05
Siemens NX Machining, Mastercam Mill-Turn, ESPRIT, and Hypermill all support the G550T mill-turn and 5-axis simultaneous capability. Grob provides post-processors for major CAM platforms. The Siemens Sinumerik One control supports Run MyVirtual Machine for offline simulation and NC code verification.
Videos
Ellis Machinery
GROB-WERKE GmbH & Co. KG
MTDCNC
GROB-WERKE GmbH & Co. KG
GROB-WERKE GmbH & Co. KG
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Links to community discussions. Summaries are editorial — visit the original thread for full context.
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