Okuma MCR-BIII
Key Specifications
X Travel
Y Travel
Z Travel
Max Spindle
Spindle Taper
Tool Capacity
Overview
The Okuma MCR-BIII is a third-generation double-column machining center from Okuma's MCR series, designed for heavy-duty 3-axis machining of large mold bases, die plates, and structural components. With travel configurations starting at 2,050 x 1,500 x 750 mm (80.7 x 59.1 x 29.5 in) and extending to larger custom sizes, it provides the rigidity and accuracy needed for large-scale precision machining.
The spindle delivers 4,000 RPM standard with 22/18.5 kW (30/25 hp) through a No. 50 (BT 50) taper. Options extend to 6,000 and 10,000 RPM for shops needing higher surface speeds for finishing operations. The third-generation design refines the spindle head and crossrail construction for improved thermal stability and better surface finish during long finishing passes.
Double-column construction provides inherently superior rigidity compared to C-frame VMCs. The crossrail-mounted spindle head maintains constant stiffness regardless of Y-axis position, eliminating the deflection that causes accuracy loss on large C-frame machines at maximum Y extension. Box-way construction on the crossrail and column guides provides vibration damping for heavy cuts.
Table configurations range from 1,500 x 2,000 mm to custom sizes exceeding 3,000 mm in length, with load capacities up to 5,000 kg (11,023 lb). The 50-tool ATC (expandable to 80, 100, or 120 tools) handles complex multi-tool programs. Automatic attachment changers (AAC) are available for head configurations that require different tool approach angles.
Okuma's Thermo-Friendly Concept manages thermal growth across the large double-column structure, and the OSP-P500 control provides advanced contouring and look-ahead processing for smooth surface generation on large mold surfaces.
New MCR-BIII machines run $500,000-$800,000 depending on size and configuration. Competitors include the SNK RB-M series, Toshiba MPF, and Mitsubishi MVR series.
Full Specifications
| Parameter | Value |
|---|---|
| X-Axis Travel | 2,050 mm (80.7 in) and larger configurations |
| Y-Axis Travel | 1,500 mm (59.1 in) |
| Z-Axis Travel | 750 mm (29.5 in) |
| Max Spindle Speed | 4,000 RPM (standard); 6,000 / 10,000 RPM optional |
| Spindle Taper | No. 50 (BT 50) |
| Spindle Motor Power | 30/22 [4/37] |
| Tool Capacity | 50 (standard); 80, 100, or 120 optional |
| Table Size | 1,500 x 2,000 mm (59.1 x 78.7 in) and larger |
| Max Table Load | 5,000 kg (11,023 lb) |
| Rapid Traverse Rate | ipm |
| Distance Between Columns | 1,800 mm (70.9 in) |
| Machine Weight | 28,000 kg (61,729 lb) |
| CNC Control | OSP-P500 |
| Guide Type | Box ways (crossrail and columns) |
| Width Between Columns | 2,050 [2,550; 3,050; 3,550] |
| Table Travel | 3,000 [4,000 - 12,000] |
| Spindle Range | 10~4,000 [10~3,600; 10~6,000; 30~8,000; 30~10,000] |
| Okuma Global Repair Center | Charlotte, North Carolina |
| Inches | Metric |
| Rapid Traverse Rate | 15 / 20 / 15 |
| Magazine Capacity | 32 [50, 72, 100, 120, 180] |
Specifications sourced from okuma.com — verified 2026-03-28
Strengths & Limitations
Strengths
- Double-column construction provides constant rigidity regardless of Y-axis position across the full travel
- Third-generation design improves thermal stability and surface finish over earlier MCR-B models
- 5,000 kg table load handles the heaviest mold bases and die plates without structural concern
- Box-way crossrail and column guides provide vibration damping for heavy roughing operations
- Configurable travel ranges accommodate custom workpiece sizes beyond standard configurations
- AAC (automatic attachment changer) option enables different head angles without manual intervention
- OSP-P500 control with advanced look-ahead produces smooth surfaces on large mold geometry
Limitations
- Starting at $500K, the investment requires consistent large-workpiece production to justify
- Standard 4,000 RPM spindle is slow for finishing; 10K RPM upgrade adds significant cost
- 28,000+ kg weight requires engineered foundation and specialized rigging for installation
- Double-column design restricts Y-direction operator access for workpiece setup and inspection
- Slow rapids at 18 m/min add non-cutting time on large parts with distributed features
Best For
Frequently Asked Questions
01
MCR-BIII machines run $500,000-$800,000 depending on travel configuration, spindle options, and tool magazine size. Custom configurations with extended X-travel and high-speed spindles push toward the upper range. Used MCR-B series machines from 2010-2016 sell for $250,000-$450,000.
02
C-frame machines deflect at maximum Y-extension because the column cantilevers the spindle head away from the base. Double-column machines support the crossrail on both sides, providing constant rigidity across the full Y-travel. For large parts where finishing passes span the full Y-axis, this eliminates dimensional taper and surface quality variation.
03
The MCR-BIII is a 3-axis machine optimized for heavy roughing and finishing on large flat and moderately contoured surfaces. The MCR-A5CII adds an A/C contouring head for simultaneous 5-axis work. The BIII costs less and is simpler to program. Choose the A5CII for complex 3D surfaces requiring simultaneous 5-axis; the BIII for large flat and 3-axis work.
04
For heavy roughing with large face mills on mold steel, the standard 4K RPM provides maximum torque. For finishing, the 10K RPM option is recommended. Many shops order two spindle cartridges: a high-torque unit for roughing and a high-speed unit for finishing, swapping them based on the operation phase.
Videos
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