Okuma Space Turn LB 4000EX II MY
Key Specifications
Max Turning Diameter
Swing Over Bed
Max Turning Length
Bar Capacity
Main Spindle Speed
Main Spindle Power
Overview
The Okuma Space Turn LB 4000EX II MY is a large-capacity CNC turning center combining the proven LB 4000EX II platform with an integrated Y-axis for off-center milling capability. The 'MY' configuration adds ±60 mm of Y-axis travel and a 12-station live tooling turret, enabling the machine to handle complete complex part machining — turning, boring, milling, drilling, and tapping — without part removal. This makes it particularly effective for aerospace frames, oil field downhole tools, large valve bodies, and energy-sector flanges that require both heavy turning and milling features.
The main spindle on the LB 4000EX II MY is rated at 30 kW (40 hp) and 1,616 Nm of torque at low speed, making it one of the more powerful turning centers in its class. Maximum turning diameter is 760 mm with a swing over bed of 1,020 mm, and the machine handles shaft workpieces up to 3,000 mm in length in the long-bed configuration. The box-way construction (as opposed to linear guides) provides maximum rigidity and vibration damping for heavy interrupted cuts common in large diameter turning of castings and forgings.
Okuma's OSP-P300L control runs the machine and includes all of Okuma's standard intelligence features: Collision Avoidance System (CAS) for crash prevention during complex mill-turn tool paths, Machining Navi for real-time chatter suppression, and Thermo-Friendly Concept thermal compensation that keeps the machine accurate through temperature fluctuations across long production shifts. The control supports both Okuma's conversational OSP language and standard EIA/ISO G-code programming.
The Space Turn LB 4000EX II MY occupies a mid-to-large segment of the CNC turning market between general-purpose production lathes and dedicated heavy-duty turning centers. Its combination of heavy turning capacity and Y-axis milling makes it a go-to choice for aerospace, defense, and oil and gas subcontractors who need to reduce the number of setups on complex, expensive raw materials where repositioning risk is unacceptable.
Full Specifications
| Parameter | Value |
|---|---|
| Max Turning Diameter | 760 mm |
| Swing Over Bed | 1,020 mm |
| Max Turning Length | 3,000 mm (long bed) |
| Bar Capacity | 105 mm |
| Main Spindle Speed | 2,500 rpm |
| Main Spindle Power | 30 kW (40 hp) |
| Main Spindle Torque | 1,616 Nm |
| Y-Axis Travel | ±60 mm |
| C-Axis Resolution | 0.001° |
| Turret Stations | 12 (driven tools) |
| Driven Tool Speed | 4,500 rpm |
| Guideway Type | Box ways |
| Control | Okuma OSP-P300L |
| Okuma Global Repair Center | Charlotte, North Carolina |
Specifications sourced from okuma.com — verified 2026-03-28
Strengths & Limitations
Strengths
- 30 kW spindle with 1,616 Nm torque handles heavy roughing of large castings, forgings, and difficult alloys without stalling
- Box-way construction provides exceptional rigidity and vibration damping for interrupted cuts on large workpieces
- Y-axis milling eliminates secondary machining center setups for milled features on large turned components
- Collision Avoidance System and Machining Navi included as standard, protecting expensive large workpieces and tooling
- Up to 3,000 mm turning length accommodates long shaft components from aerospace, energy, and industrial sectors
Limitations
- 2,500 rpm maximum spindle speed limits surface footage on smaller-diameter sections or finishing passes on hard materials
- Large footprint and weight require substantial floor space and foundation preparation beyond standard shop floors
- High acquisition cost limits accessibility for smaller job shops without a specific large-part production pipeline
Best For
Frequently Asked Questions
01
The standard LB 4000EX II is a 2-axis or C-axis turning center without Y-axis capability. The MY variant adds ±60 mm of Y-axis travel and a 12-station live tooling turret, enabling off-center milling, drilling, and tapping that the base model cannot perform. The MY configuration is significantly more expensive but eliminates secondary setups for complex parts.
02
Box ways provide superior rigidity and vibration damping for heavy cutting on large-diameter workpieces. While linear guides offer faster rapid traverse, box ways handle the high cutting forces involved in heavy roughing of castings, forgings, and large diameter workpieces that the LB 4000EX II MY typically handles.
03
The machine is rated for steel, stainless steel, cast iron, titanium, Inconel, and other nickel-based superalloys. The 1,616 Nm low-speed torque is specifically suited to roughing hard, difficult-to-cut materials at low spindle speeds where torque rather than speed determines metal removal rate.
04
Yes, though its large size makes traditional pallet automation less common. Overhead gantry robot systems and customized heavy-part handling automation are the typical approach for unmanned operation of machines this size. Okuma works with integrators to configure appropriate automation for each application.
05
The NLX 3000 is a smaller, more agile turning center with faster rapid traverse and linear guide ways suited to medium-part production. The Space Turn LB 4000EX II MY is significantly larger with box-way construction and much higher torque, targeting heavy large-part applications that the NLX 3000 cannot handle due to size and power constraints.
Videos
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Community Discussions
Capabilities and material handling — Live tooling runout : r/Machinists - Reddit
Owner experience and review — What are your experience with okuma machines? :
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Community discussion — OKUMA help!!! : r/Machinists - Reddit
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