Machine Comparison
Roku-Roku HC-658 vs Roku-Roku HC-878
Roku-Roku vs Roku-Roku · Vertical Machining Centers
Summary
The Roku-Roku HC-658 and Roku-Roku HC-878 are high-speed HSK-E40 vertical machining centers for graphite and copper electrode work and precision mold finishing, both on a Fanuc 31i-B5 control. Their listed accuracy is the same: +/-2.0 um against +/-0.002 mm positioning and +/-1.0 um against +/-0.001 mm repeatability.
The HC-878 is the larger and stronger machine: 800 mm (31.5 in) of X travel against 23.6 in, 700 mm (27.6 in) of Y against 19.6 in, a 900 x 750 mm table against 800 x 500 mm, 800 kg (1,764 lb) of load against 500 kg (1,102 lb), and 15 kW (20 HP) against 5.5 kW (7.4 HP) continuous. The HC-658 is faster, at 32000 rpm against 30,000 RPM, with 60 m/min (2,362 ipm) rapids on all axes against 36 m/min (1,417 IPM).
Specifications Comparison
| Specification | Roku-Roku HC-658 | Roku-Roku HC-878 |
|---|---|---|
| X-Axis Travel | 23.6 in | 800 mm (31.5 in) ▲ |
| Y-Axis Travel | 19.6 in | 700 mm (27.6 in) ▲ |
| Z-Axis Travel | 15.7 in | 400 mm (15.7 in) |
| Table Size | 800 x 500 mm (31.5 x 19.7 in) | 900 x 750 mm (35.4 x 29.5 in) |
| Max Table / Workpiece Load | 500 kg (1,102 lb) | 800 kg (1,764 lb) ▲ |
| Max Spindle Speed | 32000 rpm ▲ | 30,000 RPM (direct-drive) |
| Spindle Power | 5.5 kW (7.4 HP) continuous | 15 kW (20 HP) ▲ |
| Spindle Taper / Nose | HSK-E40 | HSK-E40 |
| Rapid Traverse | 60 m/min (2,362 ipm) all axes ▲ | 36 m/min (1,417 IPM) |
| Positioning Accuracy | +/-2.0 um | +/-0.002 mm (+/-0.00008 in) |
| Repeatability | +/-1.0 um | +/-0.001 mm (+/-0.00004 in) |
| Control | Fanuc 31i-B5 with AICC-2 | Fanuc 31i-B5 |
| Machine Weight | 5,500 kg (12,125 lb) | 7,500 kg (16,535 lb) |
Advantages
Roku-Roku HC-658
- 60 m/min (2,362 ipm) rapids on all axes against 36 m/min (1,417 IPM)
- 32000 rpm spindle against 30,000 RPM
- Smaller, lighter machine at 5,500 kg (12,125 lb) against 7,500 kg (16,535 lb)
Roku-Roku HC-878
- 800 mm (31.5 in) X and 700 mm (27.6 in) Y travel against 23.6 in and 19.6 in
- 15 kW (20 HP) spindle against 5.5 kW (7.4 HP) continuous
- 800 kg (1,764 lb) load on a 900 x 750 mm table against 500 kg (1,102 lb) on 800 x 500 mm
Verdict
Both suit electrode and fine mold work at the same listed accuracy. The Roku-Roku HC-658 is for small graphite and copper electrodes and micro-detail work, where 60 m/min rapids and 32000 rpm shorten cycles on light cuts. The Roku-Roku HC-878 is for dedicated electrode production cells and larger electrodes or mold plates, where 800 mm of X travel, 800 kg of load and 15 kW give room for bigger work.