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CNC Machine Tending

Application Category

OnRobot CNC Machine Tending

End-of-arm tooling for cobot lathe and mill tending — 3FG15 and 3FG25 three-finger centric grippers for round stock, 2FG7 and 2FG14 parallel grippers for prismatic parts, MG10 magnetic gripper for ferrous blanks, and the Dual Quick Changer for raw-in / finished-out cycles in a single program.

CNC tending is the highest-ROI cobot application in most job shops — and the place where the wrong gripper costs you cycle time on every part. OnRobot's three-finger 3FG15 and 3FG25 dominate round stock and lathe work because their centric grip self-centers the part, so the cobot doesn't need to position the jaws perfectly. The 2FG7 and 2FG14 parallel grippers handle prismatic mill parts with hard-jaw fingertip kits. The MG10 magnetic gripper is the right answer for flat ferrous blanks where a finger gripper would knock parts loose. And the Dual Quick Changer eliminates the single biggest waste in tending — the cycle penalty of putting a finished part down before picking up raw stock. Below: pick the right gripper for your machine and material profile.

Choose the right CNC tending EOAT

Machine & Part Profile Best OnRobot Tool Payload Why
CNC lathe — round stock, billet, shafts 3FG15 three-finger gripper Up to 15 kg Centric grip self-centers cylindrical parts; large stroke handles ø35–145 mm without fingertip changes
Heavy lathe work — castings, large billets 3FG25 heavy-duty 3-finger Up to 25 kg Pairs with UR16e/UR20 or Doosan H-Series for parts up to 25 kg; steel finger bases handle aggressive grip force
CNC mill — prismatic parts, vise loading 2FG7 parallel gripper Up to 11 kg IP67-rated for coolant exposure; configurable fingertip kits for vise alignment
High-payload mill work, fixtured parts 2FG14 high-payload parallel Up to 14 kg Larger stroke (up to 144 mm) and grip force for heavier blanks; same IP67 environmental sealing
Stamping / sheet metal blanks (ferrous) MG10 magnetic gripper Up to 10 kg Permanent magnet pickup of flat steel blanks; no fingertip wear; fast pick from stacks
Lathe / mill — raw-in & finished-out in one cycle Dual Quick Changer Two tools Mounts two grippers (e.g. raw on side A, finished on side B) — eliminates the put-down/pick-up cycle penalty

Working inside the machine envelope? The 2FG7 and 2FG14 are IP67-rated, meaning they can handle coolant spray, cutting fluid mist, and chip exposure without sealing degradation. The 3FG and MG10 families are designed for ambient shop conditions — for heavy coolant immersion, use the 2FG line or stage the part-handling outside the door.

Browse CNC Tending Grippers & Accessories

3FG15 and 3FG25 three-finger grippers, 2FG7 and 2FG14 parallel grippers, MG10 magnetic gripper, Dual Quick Changer variants, and family-specific fingertip kits and finger bases.

A complete CNC tending cell

A typical OnRobot CNC tending cell pairs four parts:

  1. Cobot: Universal Robots UR10e or UR12e for most tending applications; UR16e or UR20 for heavy lathe work and 3FG25 pairings. Doosan H-Series and FANUC CRX are strong alternatives for shops standardized on those platforms.
  2. Gripper(s): 3FG15 / 3FG25 for round stock, 2FG7 / 2FG14 for prismatic parts, MG10 for ferrous blanks. Add the Dual Quick Changer if your cycle time benefits from carrying two grippers.
  3. Machine I/O: Connect to the CNC's M-code interface or auto-door so the cobot can trigger cycle start, open the door, wait for cycle complete, and read door-open status. Most modern Haas, Mazak, Okuma and DMG MORI machines support this directly.
  4. Part presentation: Pneumatic or hydraulic vise on the mill (for cobot-controlled clamping) or chuck on the lathe. A re-grip station or part-centering fixture is often added so the cobot can correct part orientation between machine and outfeed.

Layer above the hardware: D:PLOY CNC — OnRobot's no-code application wizard that handles lathe and mill tending sequences without writing G-code-aware robot routines. Browse the full OnRobot brand catalog →

CNC Machine Tending FAQ

3FG vs 2FG — which gripper for CNC tending?

The 3FG (three-finger) family is centric — three fingers close evenly on the part, self-centering it. That's a major advantage for lathe work and any cylindrical or near-cylindrical part. The 2FG (two-finger parallel) family closes on a fixed axis and is the right choice for prismatic mill parts, vise loading, and any part with two parallel grip surfaces. Rule of thumb: round stock, billet, shafts, castings → 3FG. Square or rectangular blanks, vise-fixtured parts → 2FG.

3FG15 vs 3FG25 — which one do I need?

The 3FG15 is the everyday three-finger gripper — 15 kg payload, large stroke, fits the majority of job-shop lathe work and pairs well with UR10e and UR12e. Choose the 3FG25 when your part weight exceeds 15 kg, when you need higher grip force for slick or oily castings, or when you're tending a lathe that runs heavier billet stock. The 3FG25 has steel finger bases (vs aluminum on the 3FG15) and pairs with UR16e, UR20, or Doosan H-Series.

Will the gripper survive coolant and chips?

The 2FG7 and 2FG14 are IP67-rated and engineered for inside-the-envelope work — coolant spray, cutting fluid, and chip exposure are within their design envelope. The 3FG15, 3FG25, and MG10 are not rated for direct coolant immersion; deploy them outside the machine door or behind a chip guard if your application has heavy fluid exposure. For aggressive coolant or grinding mist environments, the 2FG line is the safe choice.

Why use the Dual Quick Changer for tending?

Without a dual changer, the cobot has to put a finished part down before picking up raw stock — that's typically 4–6 seconds of dead cycle time per cycle. The Dual Quick Changer mounts two grippers simultaneously (or a gripper plus a magnetic pickup), so the cobot can carry the finished part on side A while picking the raw blank with side B. On a 30-second machine cycle, eliminating the put-down step recovers 13–20% of cycle time and meaningfully increases parts-per-shift.

Can OnRobot grippers handle high-mix, low-volume CNC work?

Yes — this is exactly where the OnRobot ecosystem shines. The Quick Changer's 5-second tool swap means a single cobot can move between three or four different gripper configurations in a shift. Custom fingertip kits adapt the 2FG and 3FG bodies to specific part profiles without changing the gripper itself. Job shops running 50+ part numbers per week typically deploy a 3FG15 plus a 2FG7 and switch between them via Quick Changer as the production schedule changes.

Which CNC machines integrate with cobot tending?

Almost any modern CNC with M-code I/O. Haas, Mazak, Okuma, DMG MORI, Doosan, Hyundai-Wia, and most other current-generation machine tools support cobot integration through standard M-code triggers and door-open / cycle-complete signals. Older machines (pre-2005) sometimes need a retrofit I/O board. Pneumatic or hydraulic vise control adds another I/O point on mills. Our application engineering team can review your specific machine model and confirm integration before quoting the cell.

Speccing a CNC tending cell?

Send us your machine model, part profile (round vs prismatic, weight, material), and target cycle time. We'll spec the cobot, gripper, Dual Quick Changer if applicable, and machine I/O integration — and price the complete cell.

Get a Cell Quote Call 1-888-600-3080