Geminis GM7i Multiprocess mill-turn lathe with a 3-station automatic head changer
For steel makers, job shops and OEMs machining large, heavy components, reducing part handling and set-up time is critical. Moving large workpieces often requires cranes or lifts, and each re-alignment adds significant time-turning what could be a single set-up into a process that takes hours or even days.
The Geminis GMi Multiprocess Mill-Turn Lathes were designed and engineered to solve this challenge. By consolidating multiple machining operations-including turning, milling, boring and grinding-into a single set-up on one machine, manufacturers can cut production time and improve accuracy on parts with tight tolerances.
The Geminis GMi Series represent a new class of multiprocess lathes that are purpose-built for complex, large-scale components. These machines combine the flexibility and capacity of floor-type milling-boring machines with the structure and rigidity of a heavy-duty flatbed lathe while integrating C-axis, live tooling and optional Y- and Z-axis milling capabilities. This hybrid design is suited for large cylindrical parts-such as rolls, turbine rotors or rail components-that require heavy-duty turning plus keyways, pockets, drilling or contour milling.
The GMi Series features three models, GM5i, GM7i and GM9i, and can handle parts from 51" to 98" (1.3 m to 2.5 m) in diameter and 39" to 945" (1 m to 24 m) between centers, with load capacities from 15 to 150 tons.
A standout feature on GMi lathes is the automatic head changing system, which enables fast, precise transitions between different machining operations. Available heads include:
- Heavy-duty turning spindles for roughing
- Orthogonal milling/turning heads with 1° A- and B-axis indexing
- Horizontal milling heads for high-torque OD work
- Boring heads for long boring bars
- Grinding heads (manual or programmable B-axis) for wheels up to 700 mm diameter.
For grinding applications, Geminis also offers specialized cycles for plunge, traverse and taper grinding. The large-diameter wheels allow grinding up to a shoulder without interference from spindle bearings. Custom boring heads and large-diameter boring bars are also available.
For added flexibility, GMi multiprocess lathes can be equipped with automatic tool changers accommodating ISO 50, CAT 50, Capto (C6, C8, C10) and HSK (63, 100) tooling. Capacity ranges from 30 to 120 tools, and all ATCs feature an arm capable of exchanging tools with the spindle in either vertical or horizontal orientation.
The twin-drive headstock offers C-axis positioning to 0.001° with accuracy within ±2 arc seconds. Main spindle power reaches 161 HP with maximum torque of 120,000 Nm. Control options include Siemens, FANUC or Fagor CNC systems.
Geminis emphasizes operator ergonomics and visibility. The machine layout provides a direct line of sight from the operator station to the tool tip during cutting. Optional camera systems and auxiliary monitors further improve safety and efficiency by allowing operators to track tool approach and respond quickly to any issues.
For more information contact:
Phil Wyatt, Geminis Product Manager
Select Machining Technologies
910 Day Hill Road
Windsor, CT 06095
860.687.3530
pwyatt@selectmt.com
www.selectmachiningtech.com