The Workhorse of Precision Milling: VMC850 vs VMC855
In precision manufacturing, vertical machining centers with an 850mm X-axis travel represent the undisputed sweet spot in worldwide machine tool procurement. Over 60% of all medium-sized automotive parts, mold cavities, and aerospace aluminum plates fall neatly within this working envelope.
However, buyers frequently debate whether to choose the standard Lunan VMC850 or step up to the Lunan VMC855. Here is what mechanical engineering data reveals.
1. The Key Difference: Y-Axis Envelope & Span
- VMC850: X/Y/Z travel of 850 × 500 × 550 mm.
- VMC855: X/Y/Z travel of 850 × 550 × 550 mm (+50mm on Y-axis).
While an additional 50mm on the Y-axis might appear modest on paper, its mechanical realization requires an entirely different structural casting:
- Widened Column Base: To support 550mm of cross travel without overhang deflection, the VMC855 column mounting surface is expanded by 18%.
- Saddle Rigidity: The VMC855 cross saddle features heavy roller linear guideways with greater distance between rail centers, preventing yaw and pitch errors when heavy workpieces are placed near table edges.
2. Spindle Options: BT40 High-Speed vs BT50 Heavy Cutting
| Specification | Lunan VMC850 | Lunan VMC855 |
|---|---|---|
| Table Surface | 1000 × 500 mm | 1050 × 550 mm |
| Max Workpiece Load | 600 kg | 800 kg (+33%) |
| Spindle Taper | BT40 (Standard) | BT40 (Standard) / BT50 (Heavy Option) |
| Spindle Drive | Direct Drive (10,000 / 12,000 RPM) | Belt / Direct / ZF Gearbox |
| Motor Power | 7.5 / 11 kW | 11 / 15 kW |
| Net Machine Weight | 5,200 kg | 5,800 kg (+600 kg cast iron) |
3. Which Machine Matches Your Component Profile?
Choose Lunan VMC850 if:
- You produce batch automotive aluminum components, electronics frames, or pump valve plates.
- You require rapid cycle times with high acceleration (36 m/min rapid traverse).
- Your parts comfortably fit within a 500mm depth window.
Choose Lunan VMC855 if:
- You manufacture plastic injection molds or stamping dies where mold bases exceed 500mm width.
- You machine pre-hardened steels (HRC 38-45) requiring high-torque spindle options.
- You require table loads approaching 700-800 kg.
Contact our applications engineering department at xiuc32860@gmail.com for tooling layouts and spindle power torque curves.