1. The Core Engineering Distinction
When machining facilities upgrade their 3-axis milling capacity, the choice between the Luzhong VMC850 and Luzhong VMC855 is one of the most critical procurement decisions.
While both share a similar longitudinal X-axis travel (~800 to 850 mm), their structural mass, column stance, and Y-axis saddle dimensions are tailored for distinctly different machining challenges:
| Key Technical Parameter | Luzhong VMC850 | Luzhong VMC855 |
|---|---|---|
| X / Y / Z Travel | 800 × 500 × 500 mm | 850 × 550 × 550 mm |
| Table Dimensions | 1000 × 500 mm | 1100 × 550 mm |
| Max Worktable Load | 600 kg | 800 kg |
| Machine Net Weight | 5,000 kg | 5,800 kg |
| Spindle Taper | BT40 (Standard) | BT40 / Heavy BT50 Option |
| Spindle Power | 7.5 / 11 kW | 11 / 15 kW |
| Primary Sweet Spot | General Parts, Aluminum, Auto | Tool Steel, Molds, Inconel |
2. Why the 550mm Y-Axis on the VMC855 Matters
In die and mold manufacturing, part widths frequently exceed 450 mm. On a standard 500mm Y-stroke machine, tool clearance at the extreme front and back limits can restrict end mill access or force multiple fixture relocations.
The Luzhong VMC855 extends the Y-axis stroke to 550 mm and broadens the saddle base with a widened column bridge. This design allows:
- Machining standard 500mm mold base cavities without cutter overhang.
- Installation of a rigid 4th-axis CNC rotary table without obstructing the standard tool change envelope.
- Higher z-axis throat clearance for deep pocket mold cores.
3. Dynamic Rigidity & Metal Removal Rates
The VMC855 incorporates 800 kg of additional Meehanite FC-30 casting mass concentrated into the machine column and base pyramid.
When face-milling pre-hardened steel blocks (HRC 38–42) with a Ø80mm carbide cutter:
- The VMC850 achieves exceptional surface finishes with high-speed toolpaths and 36 m/min rapid feed rates.
- The VMC855 excels at aggressive radial and axial depths of cut, absorbing heavy cutting harmonics with minimal spindle deflection.
4. Which Machine Should Your Shop Select?
- Select the Luzhong VMC850 if: Your primary workload consists of production automotive brackets, aluminum enclosures, precision medical components, or medium-sized mechanical engineering parts where high-speed agility and cycle time reduction are paramount.
- Select the Luzhong VMC855 if: Your facility builds injection molds, stamping dies, forged tooling, or processes tough alloy steels where extra Y-axis cross travel, 800 kg table load, and maximum low-end torque are required.
Need a full spindle torque curve sheet and 2D/3D footprint drawing? Email xiuc32860@gmail.com for direct technical documentation.