FANUC RoboDrill a-D21MiB5 5-Axis
Key Specifications
X Travel
Y Travel
Z Travel
Spindle Taper
Rapid Traverse
Spindle Power
Overview
The FANUC RoboDrill a-D21MiB5 equipped with a DDR (Direct Drive Rotary) 5-axis table transforms the world's most popular compact machining center into a legitimate 5-axis simultaneous machining platform. This isn't a bolted-on trunnion afterthought — FANUC designed the DDR table specifically for the RoboDrill, integrating the A/C rotary axes directly into the machine's control architecture through the same 31i-B5 CNC that runs the linear axes. The result is a 5-axis machine that retains the RoboDrill's legendary speed while adding full 5-sided and simultaneous 5-axis capability.
The DDR table delivers 150 RPM on the C-axis (rotation) and 100 RPM on the A-axis (tilt), with direct-drive motors eliminating backlash entirely. Combined with the RoboDrill's 54 m/min rapids, 0.7-second tool changes, and 24,000 RPM high-speed spindle option, you get a 5-axis machine that can compete with dedicated 5-axis platforms costing twice as much on small-to-medium parts. X/Y/Z travels remain 500 x 400 x 330 mm, though the effective work envelope shrinks somewhat with the DDR table installed. Maximum workpiece diameter on the DDR is 300 mm with a height of 200 mm.
The 5-axis RoboDrill has found its strongest foothold in medical device manufacturing, where complex implant geometries, surgical instruments, and dental prosthetics demand simultaneous 5-axis contouring on small parts. Aerospace shops use it for turbine blade finishing, small structural brackets, and connector housings. The electronics industry — Apple being the most famous example — deploys these machines by the hundreds for smartphone and laptop enclosure machining where 5-axis access eliminates multiple setups.
New pricing for the D21MiB5 with DDR 5-axis table runs $130,000 to $190,000 depending on spindle speed and automation options. That's roughly $40,000-$50,000 more than a 3-axis RoboDrill, but significantly less than a dedicated 5-axis VMC from DMG Mori, Hermle, or Matsuura. The value proposition is compelling: RoboDrill-class speed and reliability with true 5-axis capability, backed by FANUC's global service network and seamless robot integration for automated 5-axis production cells.
Full Specifications
| Parameter | Value |
|---|---|
| X-Axis Travel | 500 mm (19.7 in) |
| Y-Axis Travel | 400 mm (15.7 in) |
| Z-Axis Travel | 330 mm (13.0 in) |
| A Axis Range | -120 to +30 degrees |
| C Axis Range | 360 degrees continuous |
| A Axis Speed | 100 RPM |
| C Axis Speed | 150 RPM |
| Spindle Speed | 10,000 RPM (24,000 RPM optional) |
| Spindle Motor Power | 11 kW (15 hp) standard / 26 kW (35 hp) high-speed |
| Spindle Taper | BT30 / BBT30 |
| Tool Magazine | 21-position turret |
| Tool Change Time | 0.7 sec (tool-to-tool), 1.3 sec (chip-to-chip) |
| Max Workpiece Diameter Ddr | 300 mm (11.8 in) |
| Max Workpiece Height Ddr | 200 mm (7.9 in) |
| Rapid Traverse Rate | 54 m/min (2,125 ipm) |
| Positioning Accuracy | ±0.003 mm (±0.00012 in) |
| Repeatability | ±0.002 mm (±0.00008 in) |
| CNC Control | FANUC 31i-B5 |
| Machine Weight | 4,200 kg (9,259 lb) |
Specifications sourced from emastercam.com — verified 2026-03-28
Strengths & Limitations
Strengths
- FANUC DDR direct-drive rotary table eliminates backlash entirely, delivering positioning accuracy that matches or exceeds worm-gear trunnion tables on competing 5-axis machines
- Retains the RoboDrill's 0.7-second tool change and 54 m/min rapids — most 5-axis machines in this price range are significantly slower on non-cutting moves
- Seamless integration with FANUC robots through the unified 31i-B5 control makes automated 5-axis production cells straightforward to implement
- Price point of $130K-$190K significantly undercuts dedicated 5-axis platforms from DMG Mori, Hermle, and Matsuura that start at $250K+
- 24,000 RPM high-speed spindle option excels at aluminum and light alloy 5-axis contouring with excellent surface finish capability
- Over 250,000 RoboDrills installed worldwide means proven reliability data, readily available spare parts, and deep application knowledge from FANUC and Methods Machine Tools
Limitations
- BT30 spindle taper limits cutting force capability — heavy roughing in steel or titanium is not this machine's strength compared to BT40 or HSK-A63 5-axis platforms
- DDR table reduces the effective work envelope compared to the base 3-axis RoboDrill — maximum workpiece size on the DDR is 300 mm diameter by 200 mm height
- 21-tool turret magazine can be limiting for complex 5-axis jobs requiring many tools — no option for 40+ tool capacity like some competing 5-axis machines
- FANUC's 31i-B5 control has a steeper learning curve than Heidenhain or Siemens controls that are more common in the 5-axis world
- 330 mm Z-travel restricts the height of workpieces and fixture stacks, particularly when the DDR table is installed
Best For
Frequently Asked Questions
01
The DDR (Direct Drive Rotary) table is FANUC's purpose-built 5-axis rotary unit for the RoboDrill. It uses direct-drive motors rather than worm gears for both the A-axis (tilt) and C-axis (rotation), eliminating backlash and providing high rotational speeds. The DDR integrates directly with the RoboDrill's 31i-B5 control for true simultaneous 5-axis interpolation. It's available in several sizes with the most common being the DDR for the D21MiB5, which handles workpieces up to 300 mm diameter and 200 mm height.
02
For small-to-medium parts in aluminum, brass, plastics, and light steel cutting, absolutely yes. The RoboDrill with DDR table delivers competitive accuracy and surface finish at dramatically faster cycle times due to its rapid tool changes and axis speeds. Where it falls short is on heavy cutting in hard materials (the BT30 taper is the limiting factor), very large parts (the DDR limits workpiece size), and jobs requiring more than 21 tools. For the right applications, it outperforms machines costing 2-3x more.
03
The DDR 5-axis table typically adds $40,000-$50,000 to the base RoboDrill price, bringing the total machine cost to approximately $130,000-$190,000 new depending on spindle speed and other options. This is significantly less than the $50,000-$80,000 premium that most manufacturers charge for 5-axis capability on their platforms. Used RoboDrills with DDR tables from 2017-2022 can be found in the $70,000-$120,000 range.
04
The RoboDrill with DDR accepts standard G-code with simultaneous 5-axis interpolation commands. Popular CAM choices include Mastercam, Fusion 360, hyperMILL, and NX. FANUC also offers their own CNC Guide simulation software for offline verification of 5-axis programs. Post-processors are widely available from all major CAM vendors since the RoboDrill is one of the most common 5-axis platforms in production use.
Videos
MTDCNC
Methods Machine Tools, Inc
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clarkmachinery
FANUC America Corporation
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