FANUC RoboDrill a-D21SiB5 ADV Plus
Key Specifications
X Travel
Y Travel
Z Travel
Spindle Taper
Table Size
Rapid Traverse
Overview
The FANUC RoboDrill a-D21SiB5 ADV Plus is the short-bed variant in FANUC's latest-generation RoboDrill lineup, purpose-built for ultra-fast machining of small precision parts. The 'S' designation means short-stroke — X/Y/Z travels of 300 x 300 x 330 mm — and the ADV Plus designation indicates FANUC's highest-specification package including the high-speed 24,000 RPM spindle, advanced servo tuning, and optimized control parameters for maximum throughput on small-part production.
What makes the D21SiB5 ADV Plus special isn't the travel range — it's the speed. With the smallest moving mass in the RoboDrill family, this machine achieves the fastest acceleration rates and settling times of any model. Rapid traverse hits 54 m/min on all axes, and the 21-position turret ATC delivers 0.7-second tool-to-tool and 1.3-second chip-to-chip changes. When paired with the DDR 5-axis table, the short-bed variant becomes arguably the fastest 5-axis platform available for parts under 200 mm diameter. The compact footprint of approximately 1,750 x 1,600 mm means shops can pack more machines into less floor space.
The ADV Plus package brings FANUC's latest servo technology with enhanced acceleration, fine surface finish mode for improved contouring quality, and AI contour control for complex 5-axis simultaneous paths. The 31i-B5 Plus control adds expanded memory, faster processing, and enhanced 5-axis functions including tool center point control (TCP) and tilted working plane programming. These are not optional extras on the ADV Plus — they're standard, which simplifies the buying decision.
New D21SiB5 ADV Plus machines with DDR 5-axis table price between $120,000 and $170,000. The base 3-axis version starts around $75,000. For shops machining dental implants, watch components, small medical devices, electronic connectors, and similar precision small parts, the short-bed RoboDrill with 5-axis DDR is essentially the industry standard platform. Competitors include the Brother Speedio S300Xd2 and Mikron MILL S 400, but neither matches the RoboDrill's combination of speed, reliability, and automation integration.
Full Specifications
| Parameter | Value |
|---|---|
| X-Axis Travel | 300 mm (11.8 in) |
| Y-Axis Travel | 300 mm (11.8 in) |
| Z-Axis Travel | 330 mm (13.0 in) |
| Table Size | 500 x 300 mm (19.7 x 11.8 in) |
| Max Table Load | 100 kg (220 lb) |
| Spindle Speed | 24,000 RPM (ADV Plus standard) |
| Spindle Motor Power | 26 kW (35 hp) peak |
| Spindle Taper | BT30 / BBT30 |
| Spindle Torque | 12 Nm continuous |
| Tool Magazine | 21-position turret |
| Tool Change Time | 0.7 sec (tool-to-tool), 1.3 sec (chip-to-chip) |
| Rapid Traverse Rate | 54 m/min (2,125 ipm) all axes |
| Positioning Accuracy | ±0.003 mm (±0.00012 in) |
| Repeatability | ±0.002 mm (±0.00008 in) |
| Ddr 5axis Option | Available (A-axis: -120/+30 deg, C-axis: 360 deg continuous) |
| CNC Control | FANUC 31i-B5 Plus |
| Machine Weight | 3,500 kg (7,716 lb) |
| Floor Space Required | 1,750 x 1,600 mm (68.9 x 63.0 in) |
Specifications sourced from emastercam.com — verified 2026-03-28
Strengths & Limitations
Strengths
- Fastest acceleration and settling times in the RoboDrill family due to lowest moving mass — directly translates to shorter cycle times on small-part production
- 24,000 RPM spindle is standard on the ADV Plus, not optional — no need to spec and upcharge for high-speed capability
- Compact 1,750 x 1,600 mm footprint allows higher machine density on the shop floor, critical for production environments running multiple cells
- 31i-B5 Plus control includes enhanced 5-axis functions (TCP, tilted working plane) as standard, reducing programming complexity for simultaneous 5-axis work
- Proven platform with the same reliability and automation integration as the larger RoboDrill models — FANUC robot cells are plug-and-play
- Price point of $120K-$170K with 5-axis DDR undercuts most competing 5-axis platforms by 40-60%
Limitations
- 300 x 300 mm X/Y travel is very limited — this machine is exclusively for small parts and cannot handle mid-size work that fits on the D21MiB5 or D21LiB5
- 100 kg maximum table load restricts fixture weight and limits use of heavy steel fixture plates common in production setups
- BT30 taper limits cutting force and rigidity for heavy roughing — not suited for aggressive stock removal in hardened steel or titanium
- 21-tool turret may be insufficient for complex parts requiring many different tool types and sizes
- Limited Z-travel of 330 mm constrains fixture stacking height, especially with DDR 5-axis table installed
Best For
Frequently Asked Questions
01
The 'S' stands for short-bed and 'M' for medium-bed. The D21SiB5 has 300 x 300 mm X/Y travel versus 500 x 400 mm on the D21MiB5. The short-bed model has faster acceleration due to lower moving mass and a smaller footprint. Both share the same spindle, tool magazine, and control platform. Choose the S model for parts under 250 mm, and the M model for larger parts or multi-part fixturing.
02
ADV Plus (Advanced Plus) is FANUC's highest-specification package for the RoboDrill. It includes the 24,000 RPM high-speed spindle as standard, enhanced servo tuning for faster acceleration, AI contour control, fine surface finish mode, and the 31i-B5 Plus control with expanded memory and processing power. The Standard and Advanced versions are available at lower price points but with fewer performance features.
03
The DDR 5-axis table can be added to an existing RoboDrill, but it's significantly more cost-effective to order it factory-configured. Retrofitting requires control software updates, additional servo amplifiers, and mechanical installation. Most shops that know they'll need 5-axis order the DDR from the factory. The base machine without DDR remains a capable 3-axis VMC for simpler work.
Videos
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