Fanuc Robodrill α-D21LiB5
Key Specifications
X Travel
Y Travel
Z Travel
Max Spindle
Spindle Taper
Tool Capacity
Overview
The Fanuc Robodrill α-D21LiB5 is the long-bed version of Fanuc's legendary compact machining center, and it solves the one complaint shops have always had about Robodrills: not enough X-axis travel. With 700 mm (27.5 in) of X travel compared to the standard D21MiB5's 500 mm, the D21LiB5 opens up longer workpieces and multi-part fixturing that the medium-bed model simply can't handle. Everything else that makes the Robodrill platform dominant in high-speed production carries over.
The BT30/BBT30 spindle runs up to 24,000 RPM with 26 kW (35 hp) peak power, making it a serious performer in aluminum, brass, and light alloy work. The 21-tool servo-driven turret delivers 0.7-second tool-to-tool changes and 1.3-second chip-to-chip time on the Advanced version. That's the same blistering speed as the medium-bed model. Rapid traverse hits 54 m/min (2,125 ipm) across all three axes, so you're not losing time on positioning moves even with the longer X stroke.
The table measures 850 x 410 mm (33.5 x 16.1 in), which gives you meaningful real estate for longer parts or side-by-side fixturing of smaller components. Max table load is 300 kg (660 lb). Y-axis travel is 400 mm (15.7 in) and Z is 330 mm (13 in), matching the medium-bed model. Positioning accuracy comes in at ±0.003 mm (±0.00012 in) with repeatability of ±0.002 mm (±0.00008 in).
Fanuc runs everything through their 31i-B5 control, which is the same platform powering their industrial robots and CNC systems worldwide. It's not the most intuitive control if you're coming from Haas or Mazak, but it's bulletproof and offers high-speed look-ahead, AI contour control, and nano interpolation. The Robodrill also integrates seamlessly with Fanuc LR Mate robots for automated load/unload cells, which is how many production shops run them around the clock.
New pricing typically falls between $90,000 and $140,000 depending on spindle options, the Standard vs. Advanced version, and automation packages. Used D21LiB5 models from 2017-2021 sell in the $45,000-$80,000 range. Methods Machine Tools is the exclusive North American distributor, with a strong service network. The D21LiB5 competes with the Haas DT-2 on versatility and the Brother Speedio S700 on speed, but it's the go-to choice when you need Robodrill-class cycle times with room for longer parts. Specs sourced from Fanuc published data, Methods Machine Tools, and machinery dealer documentation.
Full Specifications
| Parameter | Value |
|---|---|
| X-Axis Travel | 700 mm (27.5 in) |
| Y-Axis Travel | 400 mm (15.7 in) |
| Z-Axis Travel | 330 mm (13 in) |
| Max Spindle Speed | 10,000 RPM (24,000 RPM optional) |
| Spindle Taper | BT30 / BBT30 |
| Spindle Motor Power | 14.2 kW (19 hp) peak @ 10K RPM; 26.0 kW (35 hp) peak @ 24K RPM |
| Spindle Torque | 79.7 Nm (58.8 ft-lbf) @ 1,700 RPM (10K spindle); 35 Nm @ 24K spindle |
| Tool Capacity | 21 turret |
| Max Tool Length | 250 mm (9.8 in) |
| Max Tool Diameter | 80 mm (3.1 in) |
| Max Tool Weight | 4 kg (8.8 lb) |
| Tool To Tool Time | 0.7 sec (ADV); 0.9 sec (Standard) |
| Chip To Chip Time | 1.3 sec (ADV); 1.5 sec (Standard) |
| Table Size | 850 x 410 mm (33.5 x 16.1 in) |
| Max Table Load | 300 kg (660 lb) |
| Spindle Nose To Table | 250-580 mm (9.8-22.8 in) |
| Rapid Traverse Rate | 54 m/min (2,125 ipm) |
| Max Cutting Feedrate | 30,000 mm/min (1,181 ipm) |
| Positioning Accuracy | ±0.003 mm (±0.00012 in) |
| Repeatability | ±0.002 mm (±0.00008 in) |
| Machine Weight | 2,300 kg (5,070 lb) |
| CNC Control | Fanuc 31i-B5 |
| Number Of Tools | 21 |
Strengths & Limitations
Strengths
- 700 mm X-axis travel gives 40% more reach than the medium-bed D21MiB5, enabling longer parts and multi-part fixturing without sacrificing Robodrill-class speed
- Tool-to-tool change in 0.7 seconds and chip-to-chip in 1.3 seconds on the Advanced version make it one of the fastest tool changers in any VMC class
- 54 m/min rapids across all axes mean virtually zero wasted time on positioning moves, even with the extended X stroke
- 24,000 RPM high-speed spindle option with 26 kW peak power makes it exceptional for aluminum and light alloy high-speed machining
- Fanuc 31i-B5 control is the same platform running millions of Fanuc robots and CNCs worldwide, offering proven reliability and seamless robot cell integration
- 850 x 410 mm table provides meaningful work area for side-by-side part fixturing, tombstone setups, or longer single workpieces
Limitations
- BT30 taper limits rigidity for aggressive cuts in steel and hardened materials; this is a speed machine, not a heavy metal removal platform
- Fanuc 31i control has a steeper learning curve than Haas NGC or Mazak SmoothG, and shops switching from those platforms will need dedicated training
- 13-inch Z-axis travel restricts tall part work; there's no extended Z option on the long-bed model to compensate
- 4 kg max tool weight and 80 mm max tool diameter rule out large face mills and heavy boring bars common on 40-taper machines
- New pricing starts around $90K, a significant premium over the Haas DT-2 at roughly $50K and even over the medium-bed Robodrill
Best For
Frequently Asked Questions
01
The 'L' stands for Long bed and the 'M' for Medium bed. The D21LiB5 gets 700 mm of X-axis travel versus 500 mm on the D21MiB5, along with a larger table (850 x 410 mm vs 650 x 400 mm). The machine is about 300 kg heavier to accommodate the longer bed. Y and Z travel, spindle options, tool capacity, and tool change times are identical between the two models. Choose the L if your parts or fixtures need the extra X reach; stick with the M if compactness is more important.
02
The Robodrill D21LiB5 changes tools in 0.7 seconds versus 2.2 on the DT-2, and rapids at 2,125 ipm versus 1,200. The Robodrill has slightly more X travel (27.5 vs 26 inches) but less Z (13 vs 20 inches). The Haas wins on price (roughly $50K vs $90K+), Z-travel, and control ease-of-use. If cycle time and throughput drive your bottom line, the Robodrill wins. If budget, Z-travel, and versatility matter more, the DT-2 is hard to beat.
03
The Advanced (ADV) version gets faster tool changes at 0.7 seconds tool-to-tool versus 0.9 on the Standard, and 1.3 seconds chip-to-chip versus 1.5. It also includes high-speed look-ahead, AI contour control, and nano interpolation as standard features. Most production shops buy the ADV because those fractions of a second per tool change compound across thousands of parts per shift.
04
Yes, but with limitations. The BT30 taper doesn't have the rigidity of a 40-taper machine for aggressive steel roughing. Shops cut mild steel, 4140, and even stainless on Robodrills regularly, but they use lighter cuts at higher speeds and rely on the machine's accuracy rather than brute force. For heavy steel removal, a 40-taper VMC like the Haas VF-2 or Okuma GENOS M560-V is a better fit.
05
Methods Machine Tools is the exclusive North American distributor for Fanuc Robodrills. They offer sales, service, applications engineering, and automation integration through locations across the US. Fanuc also has direct service capabilities through their network. Used Robodrills are widely available through machinery dealers, and the large installed base means independent service providers are common too.
06
The D21LiB5 supports 5-axis machining with optional rotary tables from Fanuc or third-party suppliers. The extra X travel can actually be an advantage for 5-axis work on longer parts. However, the 300 kg table load limit means you need to account for the weight of the rotary table plus the workpiece. Many shops run the long-bed Robodrill with a DDR (Direct Drive Rotary) table for simultaneous 5-axis contouring.
Videos
Methods Machine Tools, Inc
Tramar Industries
Revelation Machinery
Methods Machine Tools, Inc
PrestigeEquipment
Community Discussions
Troubleshooting and problem-solving — FANUC Robodrill Alpha D21liB5ADV tool life ...
Community discussion — Robodrill footprint and dimensions - Practical Machinist
Pricing and buying discussion — New Robodrill or 7000 hour robodrill with all the bells and ...
Community discussion — Fanuc Robodrill - Practical Machinist
Community discussion — ROBODRILL ?-D21LiB5
Community discussion — Need Help! Fanuc/Robodrill rapid feed parameters - CNCzone
Community discussion — postprocessor FANUC ROBODRILL ?-D21LiB5 - cnczone.com
Community discussion — FANUC ROBODRILL NEED HELP - CNCzone
Community discussion — Anyone got a Fanuc Robodrill? I'm trying to set up the ...
Owner experience and review — Learning on a Robodrill? : r/Machinists - Reddit
Community discussion — Breaking milling tools in robodrill. : r/Machinists - Reddit
Community discussion — Fanuc Robodrill keep relay lookup : r/Machinists - Reddit
Links to community discussions. Summaries are editorial — visit the original thread for full context.
