Raw and finished geometry
Identify usable grip features before and after processing, including dimensional change, sharp edges and delicate surfaces.
End-of-arm tooling and part flow
Machine-tending grippers and part presentation designed together.
Grip, locate and confirm raw and finished components reliably using tooling, sensing and part supply matched to the real surfaces, variants, cycle and autonomy target.
Find the partPresent a known position or detect its pose
Hold it securelyControl raw and finished conditions
Confirm each stateDetect pick, grip, seating and release
Store enoughProvide useful unattended capacity
Direct answer
What are machine-tending grippers and part presentation?
The gripper is the robot's end-of-arm tool for picking, loading and unloading a component. Part presentation is the method used to place raw parts where the robot can find and grip them, using equipment such as trays, drawers, pallets, conveyors, feeders or vision-guided bins.
They must be designed as one system. A capable gripper cannot correct an unreliable supply position, while precise trays do not help if the tool cannot handle coolant, swarf, changing surfaces or the geometry of both raw and finished parts.
Payload includes more than the component. Gripper bodies, fingers, adapters, valves, sensors, cameras, hoses and every part carried at the same time affect payload, centre of gravity, reach and robot performance.
Part-presentation choices
Match repeatability and flexibility to the production pattern.
| Presentation method | Useful when | Questions to resolve |
|---|---|---|
| Machined trays or pallets | Parts can be loaded into repeatable nests and controlled orientation is valuable. | Capacity, manual loading time, nest tolerance, part protection and changeover. |
| Drawer system | Operators need to replenish one area while the robot continues from another. | Drawer confirmation, safe access, usable rows and finished-part return positions. |
| Conveyor or indexing belt | Parts arrive continuously or must transfer between processes. | Spacing, orientation, tracking, accumulation, stopped parts and upstream control. |
| Bowl or step feeder | Smaller components can be separated and oriented at the required rate. | Part damage, noise, variant range, recirculation and buffer capacity. |
| Stack or magazine | Simple parts can be separated reliably from a controlled stack. | Double-pick detection, variable stack height, material friction and refill access. |
| 2D or 3D vision | Part position varies on a surface, conveyor or in a bin. | Visibility, lighting, overlap, surfaces, pick success, calibration and recovery. |
Gripper engineering checklist
Design around every component state and credible failure.
Process environment
Account for coolant, swarf, oil, heat, release agent, dust or moisture on both the component and tooling.
Grip confirmation
Use position, pressure, vacuum, proximity or other suitable sensing to distinguish a valid pick from likely failures.
Machine access
Check fingers, services, wrist orientation and component clearance through the complete load and unload path.
Changeover method
Choose adjustable fingers, manual tooling change, automatic tool changing or separate tools from the real part matrix.
Failure route
Define what happens after a missing part, failed grip, blocked nest, lost vacuum or uncertain component state.
Cycle and autonomy
Reduce machine-open time without overloading the robot.
A dual gripper can remove the completed part and load the next blank during one machine visit. It can reduce exchange time, but it also adds mass, inertia, width and access constraints. The benefit must be checked through the actual robot path and every part variant.
- Measure the complete exchange, including doors, clamps and checks
- Calculate payload with both components and all tooling services
- Confirm wrist clearance at the deepest machine position
- Separate raw and finished gripping conditions where necessary
- Allow safe replenishment before the presentation system becomes empty
- Protect finished surfaces and keep rejected or uncertain parts separate
Frequently asked questions
Gripper and presentation questions, answered.
Is a dual gripper always faster for CNC machine tending?
It often reduces machine-open time, but the second gripper adds payload, inertia and size. The gain must be checked against robot capacity, wrist orientation, machine access and the actual exchange sequence.
Can one robot gripper handle several part sizes?
It can where the defined range supports adjustable or adaptive fingers and secure location. Wider part families may need interchangeable fingers, a tool changer or separate tools with recipe confirmation.
When is vision-guided part presentation worthwhile?
Vision can add flexibility where part position or orientation varies, but reliable imaging, calibration, pick access and a recovery route are essential. A fixed tray may remain the simpler option when the part and batch are stable.
How is part-presentation capacity calculated?
Start with the target unattended time and sustainable good-part rate, then include raw-part quantity, finished-part positions, rejects, variants, replenishment time and the space available around the machine.