Mitsubishi M-VS25/20 CNC Double Column Vertical Machining Center – Year 1996

Table: 157″L x 78.7″ W
Load Cap: 55,000 LBS
Throat: 98.4″
Travel: X = 165″
Travel: Y = 98″
Travel: Z (WO/APC) = 78.7″
Travel: X (W/APC) = 63″
Feed Rate: .05-300 IPM
Spindle Speed: 40-4,000 RPM
ATC= 60
16 T-SLOTS (9.843″ SPACE)
Spindle: Dia. 9.50″

Equipped With:

Fanuc-15MB Control
60 ATC
Conveyor

Mitsubishi M-VS25/20 CNC Double Column Vertical Machining Center – Technical Evaluation (Year 1996)
1. Technical Evaluation Overview

The Mitsubishi M-VS25/20 is a large-format double column vertical machining center manufactured in 1996, designed for heavy-duty milling of large and heavy workpieces. Based strictly on the provided information, the machine is equipped with a 157″ × 78.7″ table and a maximum table load capacity of 55,000 lbs, indicating a platform intended for substantial structural components.

Axis travels are specified as X 165″, Y 98″, and Z 78.7″ (without APC), with an alternate X travel of 63″ when equipped with APC. The machine features a throat of 98.4″, supporting wide workpieces between columns. Feed rates are stated from 0.05 to 300 IPM, and the spindle operates within 40–4,000 rpm. The spindle diameter is 9.50″, emphasizing rigidity over high-speed capability.

Tool handling is via a 60-position automatic tool changer (ATC). Control is provided by FANUC 15MB, and chip management includes a chip conveyor. The table incorporates 16 T-slots with 9.843″ spacing.

Key details not provided include spindle motor power/torque curve, spindle taper type, positioning accuracy/repeatability, acceleration, coolant pressure, and whether an APC is currently installed. These should be verified.

2. What to Check Before Buying

Given the machine size, age, and partial specification set, inspection should focus on:

Structure and geometry:

Condition and alignment of the double column structure, cross-rail, and guideways across the full X/Y travels.

Table flatness and integrity under high loads (up to 55,000 lbs).

Verification of throat clearance and column parallelism.

Spindle and drive system:

Condition of the low-speed, high-rigidity spindle (40–4,000 rpm), including bearing noise and thermal stability.

Confirmation of spindle motor power and torque delivery (not specified).

Inspection of spindle nose and interface (taper not stated).

Axes, ATC, and auxiliaries:

Backlash and following error on long axes; smooth motion at low feedrates.

Reliability of the 60-ATC indexing and clamping.

Operation of the chip conveyor and coolant distribution over the large table.

CNC and electrics:

Health of the FANUC 15MB control, options installed, parameter backups, and alarm history.

Electrical cabinet condition and cooling appropriate for prolonged heavy cutting.

3. Typical Industrial Applications

Based strictly on the stated envelope and capacity, the M-VS25/20 is technically suitable for:

Heavy milling of large plates, frames, and welded structures requiring high rigidity.

Machining of large prismatic components where table load and throat width are critical.

Operations prioritizing torque and stability over high spindle speed.

Specific materials, achievable tolerances, and productivity metrics require validation.

4. Common Risks in Used Machines

Typical risks for used large double column VMCs include:

Guideway wear or misalignment over long travels, affecting geometry.

Spindle wear in heavy-duty service.

Control obsolescence, depending on FANUC 15MB hardware condition and spares.

Incomplete documentation, including missing parameters or maintenance records.

5. Maintenance and Service Considerations

With no service history provided, considerations are general:

Regular inspection of lubrication systems, guideways, and spindle bearings is essential.

Periodic geometry checks (leveling, squareness) are recommended due to machine size.

CNC parameters and ladder data should be backed up prior to continued operation or relocation.

Any refurbishment planning should be based on on-site inspection and test machining rather than assumptions.

Final Note:
The Mitsubishi M-VS25/20 is a heavy-duty double column vertical machining center with a very large table and high load capacity, suited for demanding structural machining. While the provided information outlines its core capacity, a complete technical evaluation requires confirmation of spindle power/taper, APC configuration, accuracy performance, and control options through direct inspection and testing.