Key number
Adaptive electric envelope is mode-dependent
10-240 N
OnRobot 3FG15 datasheet v2.0: flexible grip caps at 140 N, normal grip reaches 240 N [S2].
Hybrid Page · Tool + Report
Use the tool first to size required force/torque per finger, then use the report layer to choose topology (adaptive electric, pneumatic 3-point, or custom), validate assumptions, and reduce RFQ risk.
Published: 2026-05-25 · Last reviewed: 2026-05-25
Tool Layer
Enter payload and contact assumptions to get required force/torque per finger, then route to the next executable path.
Empty state: enter values and click Calculate sizing.
You will get required normal force, per-finger torque, and a decision band.
Report Layer
This section compresses the most decision-relevant numbers, who this page is for, and who should escalate to custom design immediately.
Key number
Adaptive electric envelope is mode-dependent
10-240 N
OnRobot 3FG15 datasheet v2.0: flexible grip caps at 140 N, normal grip reaches 240 N [S2].
Key number
Grip physics changes payload logic
2.5 kg vs 10 kg
Robotiq manual lists 2.5 kg fingertip and 10 kg encompassing recommendations at mu=0.6, SF=2 [S3].
Key number
Pneumatic 3-point can exceed adaptive force
87-750 N
Festo DHDS datasheet shows 87-750 N total closing force at 6 bar (sizes 16/32/50) [S5].
Key number
Cell-level safety baseline
ISO 10218-2:2025
Robot-cell integration and end-effector hazards are validated at application level in ISO 10218-2:2025 [S7].
Key number
Utility stack is topology-gated
24 V vs 2-8 bar
Electric options here run on 24 V class supply, while pneumatic DHDS requires 2-8 bar compressed air to ISO 8573-1:2010 [7:4:4] [S2, S3, S5].
Key number
Lifecycle claims are model-specific
1M to 5M cycles
Robotiq pads/fingertips are consumables after max 1 Mio. cycles, while OnRobot and SCHUNK publish separate cycle/warranty envelopes [S2, S3, S4].
Tool results are only useful if assumptions are explicit. This layer documents model choices and data sources so teams can reproduce decisions, with standards boundaries and unresolved evidence explicitly marked.
Evidence update: 2026-05-25
Review cadence: every 6 months or when core vendor datasheets are revised.
| Model parameter | Setting | Why it exists |
|---|---|---|
| Force model | F_total >= (m * g * orientation * dynamic * SF) / μ | Converts payload risk into required normal force under friction hold. |
| Finger split | Per-finger force = F_total / 3 | Three contacts are assumed to share normal force evenly in first pass. |
| Torque conversion | T_finger = F_finger * r | Maps force to actuator demand by jaw radius from pivot axis. |
| Safety factor default | 2.0 | Practical starting value for early RFQ before full test evidence. |
| Grip-physics boundary | This model targets friction-dominant fingertip grip | Robotiq documents that encompassing stability is no longer friction-driven. |
| Catalog force boundary | Force varies by finger angle, diameter, and grip mode | OnRobot force charts and notes show angle/current/material dependencies. |
| Boundary policy | Mid-band => dual-track RFQ, out-of-range => custom sizing path | Prevents false confidence from single-catalog matching. |
| Boundary topic | Verified signal | Required action |
|---|---|---|
| Grip physics | Robotiq manual distinguishes fingertip (friction-dependent) vs encompassing (not primarily friction-dependent) stability. | Use this checker for fingertip-dominant cases; re-run with lower μ and verify if encompassing fixture can be applied. |
| Force window interpretation | OnRobot states force depends on finger angle, diameter, current limits, and material friction. | Do not treat catalog max force as constant across all diameters and motions. |
| Geometry offset sensitivity | OnRobot warns finger offset >0.5 mm at first contact can overload motor and gear. | Add fixture concentricity checks and finger-runout measurement before pilot. |
| Finger length and inertia | SCHUNK publishes max finger length/mass limits; Robotiq and OnRobot provide custom finger constraints. | For long/custom fingers, demand static/dynamic load calculations and proof test records. |
| Utility and environment envelope | Electric and pneumatic options require different utilities; Festo also excludes aggressive media/welding spatter/grinding dust. | Treat utility and environment fit as first-pass gating criteria before comparing force tables. |
| Source | Signal used | Date | Reference |
|---|---|---|---|
| S1OnRobot 3FG15 product page | Positions this model for cylindrical parts and diameter variation in 3-finger topology. | Reviewed 2026-05-25 | Open source |
| S2OnRobot 3FG15 datasheet v2.0 | Force 10-240 N (10-140 N flexible), 20-25 V supply, IP67, warranty 3 years or 3,000,000 cycles, torque limits for custom fingers. | Version label v2.0, reviewed 2026-05-25 | Open source |
| S3Robotiq 3-Finger instruction manual (official PDF) | Payload split (2.5 kg fingertip vs 10 kg encompassing), 24 V control, 0.05 mm repeatability, and consumable-life warning for pads/fingertips. | Manual revision 2021-06-17, reviewed 2026-05-25 | Open source |
| S4SCHUNK EGU 70 EI-M-B technical details | 650-1,950 N force, 70 mm stroke per jaw, IP67 electronics with IP40 guide/base jaws, and 24-month cycle-based warranty terms. | Reviewed 2026-05-25 | Open source |
| S5Festo DHDS three-point gripper datasheet | Total closing force 87-750 N at 6 bar, 2-8 bar operating pressure, ISO 8573-1:2010 [7:4:4] compressed-air requirement, and environment cautions. | Reviewed 2026-05-25 | Open source |
| S6ISO 10218-1:2025 | Edition 3 (2025-02). Defines robot-as-machine safety scope and explicit non-applicable domains. | Published 2025-02 | Open source |
| S7ISO 10218-2:2025 | Edition 2 (2025-02). Covers integration/commissioning/operation/maintenance/decommissioning for robot applications and cells. | Published 2025-02 | Open source |
| S8ISO/TS 15066:2016 | Collaborative-operation supplement to ISO 10218; ISO lifecycle marks 90.92 (to be revised, 2025-06-26) and indicates replacement by ISO/AWI 15066-1 under development. | Published 2016-02; lifecycle checked 2026-05-25 | Open source |
| S9ISO 12100:2010 | Risk assessment and risk reduction methodology for machinery safety lifecycle | Published 2010-11; last confirmed 2022 | Open source |
| S10OSHA 29 CFR 1910.212 | Requires point-of-operation guarding and machine-area protection using one or more guarding methods. | Accessed 2026-05-25 | Open source |
Core conclusions reference these IDs (for example, [S2], [S5], and [S7]) so procurement and engineering teams can verify each claim quickly.
| Framework | What it covers | Decision impact |
|---|---|---|
| ISO 10218-1:2025 | Defines robot-level safety; integration and application hazards are handled in ISO 10218-2. | Catalog matching is only a start. Cell-level safeguards and misuse analysis still required. |
| ISO 10218-2:2025 | Covers design/integration/commissioning/operation/decommissioning of robot cells and integrated components. | If your scenario falls into excluded domains (public access, lifting people, explosive environment), this page output is non-decisive. |
| ISO/TS 15066:2016 | Supplement for collaborative operation; currently marked as to-be-revised by ISO lifecycle status. | For human-robot shared spaces, verify latest revision path before locking force/pressure criteria. |
| OSHA 1910.212(a)(1)-(3) | Requires guarding for point-of-operation and machine hazards in U.S. workplaces. | End-effector selection must include guard/interlock concept, not only force sizing. |
| Open question | Current status | Minimum executable fallback |
|---|---|---|
| Continuous-duty thermal derating curves at max force | No reliable public curve found for all compared models (checked 2026-05-25). | Request vendor thermal derating data by duty cycle, ambient temperature, and supply current before PO. |
| Public fatigue life for custom finger geometries | Vendors provide baseline limits but not universal fatigue life for arbitrary custom fingers. | Define minimum life test protocol (cycles, load profile, failure criteria) in RFQ. |
| Site-specific friction drift across production lots | No transferable public dataset for your exact material/pad contamination pair. | Create incoming QA friction sampling and attach lower-bound μ to the sizing worksheet. |
| Cross-vendor public pricing and lifecycle TCO | No reliable apples-to-apples public pricing dataset (some catalogs are login-gated and utility costs are site-dependent). | Build a should-cost sheet from vendor quotes, consumables, utility tariffs, and maintenance interval assumptions. |
| Final publication date for ISO/AWI 15066-1 | ISO lifecycle confirms replacement work is under development, but no final publication date is publicly fixed (checked 2026-05-25). | Use current ISO/TS 15066 + ISO 10218-2 criteria now, and add a standards-delta review gate before commissioning sign-off. |
Compare options using reproducible dimensions: force, stroke, retention behavior, utility/environment requirements, use-case fit, and known limitations.
| Option | Payload | Force range | Stroke | Power-loss / retention | Utility / environment | Best fit | Known limits |
|---|---|---|---|---|---|---|---|
| OnRobot 3FG15 (adaptive 3-finger) | Force-fit 10 kg; form-fit 15 kg | 10-240 N (10-140 N flexible) | External up to 152 mm, internal up to 176 mm | Brake holds grip on power loss | 20-25 V supply, 43-1500 mA, IP67 | Mixed-diameter handling with self-centering topology | Force and speed depend on finger angle, diameter, and friction/material pair |
| Robotiq 3-Finger (adaptive 3-finger) | 2.5 kg fingertip, 10 kg encompassing | Actuation 40 N pinch equivalent, 100 N break-away | 0-167 mm opening, 155 mm max encompassing diameter | Self-locking raises break-away force over actuation | 24 V DC +/-10%, 1 A peak, up to IP67 | Best when geometry supports encompassing grip | Fingertip stability is friction-sensitive; object detection can miss thin parts |
| Festo DHDS (pneumatic 3-point, example range) | N/A (force and geometry led) | 87-750 N total closing force at 6 bar (model dependent) | N/A (model-specific) | Depends on pneumatic circuit and pressure-hold strategy | 2-8 bar compressed air, ISO 8573-1:2010 [7:4:4] | High-force gripping with simple on/off valve control | Force depends on pressure/lever arm and this model is not designed for aggressive media, welding spatter, or grinding dust. |
| SCHUNK EGU 70 (parallel electric gripper) | N/A (force-driven selection) | 650-1,950 N | 70 mm per jaw | 80-100% gripping-force maintenance version available | 24 V, 6 A peak, IP67 electronics + IP40 guide/base jaws | High-force tasks with predictable parallel-jaw contact | Not a 3-finger topology; finger length and mass limits strongly constrain setup |
| Custom 3-finger actuator module | Defined by test plan | N/A until validated | Custom | Depends on brake/mechanism architecture | Defined by custom power/air/sealing architecture | Out-of-range scenarios or special geometry requirements | Higher integration, safety, and lifecycle validation effort |
| Risk | Probability | Impact | Mitigation action |
|---|---|---|---|
| Slip during acceleration spikes | Medium-High | High | Increase friction certainty, validate dynamic multiplier with motion trace data. |
| Torque underestimation from long fingers | High | High | Measure real jaw radius and include finger mass/inertia in the model. |
| Catalog force misread as safe payload | Medium | High | Map force to part geometry and friction, not only to payload headline. |
| Unstable pad friction in production | Medium | Medium-High | Run lot-level friction checks and define replacement intervals (Robotiq pads are consumables). |
| Safety scope mismatch with actual deployment | Medium | High | Map application scope against ISO 10218-2 exclusions and run ISO 12100-style hazard review. |
| Utility mismatch (power/air) discovered after shortlist | Medium | High | Lock 24 V power budget or 2-8 bar air + ISO 8573-1 class at RFQ gate before model comparison. |
| Ingress and environment mismatch in dirty cells | Medium | Medium-High | Map IP and media limits to real coolant/dust exposure, then require contamination test evidence before PO. |
| Gate | Verified evidence | Failure mode if skipped | Minimum action now |
|---|---|---|---|
| Utility envelope locked before RFQ | OnRobot lists 20-25 V supply; Robotiq uses 24 V DC; Festo DHDS requires 2-8 bar compressed air to ISO 8573-1:2010 [7:4:4]. | Comparisons become non-reproducible when electric and pneumatic assumptions are mixed after vendor shortlist. | Freeze power and air boundary assumptions in one worksheet before requesting quotes. |
| Environment and ingress fit checked | Festo DHDS excludes aggressive media, welding spatter, and grinding dust; SCHUNK splits IP67 electronics and IP40 guide/base jaws. | Early pilot passes can fail in production when contamination and cleaning cycles differ from lab setup. | Add contaminant and wash-down scenario to verification plan before final supplier lock. |
| Lifecycle and consumables clarified | OnRobot publishes 3 years or 3,000,000 cycles warranty; SCHUNK publishes 24 months with cycle windows; Robotiq flags pads/fingertips as consumables after max 1 Mio. cycles. | Maintenance cost can dominate total cost when consumable replacement intervals are not budgeted. | Request cycle-test protocol and consumable replacement plan as mandatory RFQ attachment. |
| Safety standard scope aligned | ISO 10218-1/2 list non-applicable domains (e.g., public access, lifting people, explosive environments); ISO/TS 15066 is marked to be revised. | A numerically good sizing result can still be non-compliant for the deployment context. | Run ISO 12100 hazard analysis and maintain a delta review checkpoint for the ISO/AWI 15066-1 transition. |
If your force/torque result is near boundary, send assumptions now and lock a validation path before pilot tooling is frozen.
Each scenario maps assumptions to an action path, so the team can decide quickly without skipping validation.
Assumption: 2.5 kg part, μ=0.35, dynamic=1.25, radius=22 mm.
Process: Checker result lands in review band; move to pad upgrade + slip test.
Output: Run electric-adaptive and pneumatic 3-point in parallel, then lock by slip test plus cycle-time fit.
Assumption: 0.8 kg part, μ=0.6, dynamic=1.0, radius=16 mm.
Process: Checker result lands in good-fit band with safety margin.
Output: Catalog adaptive 3-finger is usually enough; decide electric versus pneumatic by control and cleanliness requirements.
Assumption: 4.2 kg with eccentric center of mass and quick repositioning.
Process: Result often jumps to out-of-range due torque demand.
Output: Switch to custom 3-finger module or redesign fixture/orientation path.
Assumption: Measured μ varies from 0.2 to 0.5 across batches.
Process: Run worst-case input to set lower bound before RFQ.
Output: Use conservative SF and define friction re-test checkpoint in QA plan.
Assumption: Sizing result is good-fit, but shared-workspace force/pressure limits are not validated yet.
Process: Treat checker output as preliminary only and move to ISO 10218-2 + ISO/TS 15066 assessment path.
Output: Decision stays pending until safety validation evidence is complete.
Grouped answers for sizing, integration reliability, and procurement execution.
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