| Robot axes and layout | Pick-and-place, loading, screwdriving, and part insertion within a compact assembly cell. | A 4-axis SCARA or Cartesian robot can suit fast, mostly planar transfers. Consider a 6-axis robot when parts need angled insertion, multiple approach directions, or access around fixtures. | Check reach, work envelope, mounting orientation, access to all stations, and whether the required tool orientation can be achieved without collisions. |
| Payload | Small components such as contacts, springs, terminals, screws, toggles, and molded parts, handled with a gripper or driver. | Begin by estimating the complete moving load. For many small-part operations, a robot in roughly the 1–5 kg payload class may be a useful evaluation range; larger tooling or multiple-part handling may require more capacity. | Include the end effector, adapters, cables, and the heaviest part in the payload calculation. Confirm allowable wrist moment and inertia, not just the headline payload. |
| Repeatability and placement | Consistent placement of small parts into nests, housings, contact assemblies, and screw locations. | Compare the robot's specified repeatability with the assembly tolerance and fixture accuracy. Use precision nests and controlled part presentation for tight insertion tasks. | Robot repeatability alone does not determine final assembly accuracy. Validate the complete system, including calibration, gripper compliance, fixture variation, and part tolerances. |
| Vision system | Part presence checks, orientation correction, position compensation, and inspection for missing or misplaced components. | Use 2D vision for parts presented on a flat plane with visible features. Consider 3D vision when height, depth, overlap, or variable orientation must be measured. | Test with actual part colors, reflective metal contacts, shadows, surface finishes, and expected presentation variation. Define lighting, camera field of view, and inspection limits. |
| Feeders for screws and small metal parts | Reliable delivery of screws, springs, contacts, and terminals to a repeatable pickup point. | Vibratory bowl feeders are commonly used for high-volume, well-defined part shapes. Step feeders can provide gentler, quieter presentation for some parts; trays or magazines suit controlled batches. | Check for tangling, scratching, part-to-part variation, orientation stability, replenishment needs, and changeover time. Run a feeder trial using production-intent parts. |
| Feeders for molded housings and larger components | Presentation of insulating housings, covers, toggles, and arc-chamber components without damage or jams. | Use dedicated trays, magazines, nests, or part-specific feeders where geometry and surface protection matter. A flexible feeder with vision may be suitable for mixed or variable presentations. | Confirm that the feed method avoids deformation, cosmetic damage, nesting, and orientation ambiguity. Include a practical replenishment and recovery method. |
| End effector and insertion method | Handling fragile springs and small contacts, placing insulating components, or driving fasteners. | Select fingers, vacuum tooling, compliant grippers, or a driver based on part geometry and surface. Use controlled compliance or force monitoring where insertion forces and alignment are sensitive. | Check grip security, part access, tool changes, screw bit wear, cable routing, and whether the tool can release parts without shifting them in the fixture. |
| Cycle time and line integration | Coordinated handling across assembly, fastening, inspection, and transfer stations. | Set a target cycle time from the required line output, then validate it with the full sequence, feeder behavior, robot motion, and inspection steps. | Request a representative cycle-time trial. Include feeder recovery, part replenishment, safety interlocks, upstream and downstream interfaces, and planned changeovers. |
| Quality checks and traceability | Detection of missing parts, incorrect orientation, incomplete fastening, or assembly errors before the next process step. | Combine vision checks with suitable process monitoring, such as screw-driving results or presence sensors, where the operation requires it. | Define pass/fail criteria, data records, reject handling, and verification procedures. Confirm that inspection can detect the specific defects that matter. |
| Safety and maintainability | Safe operation around operators, feeders, fixtures, and service access points. | Design the cell risk assessment around the complete application. Use appropriate guarding, interlocks, emergency stops, and safe access for replenishment and maintenance. | Review applicable local machinery-safety requirements, service access, spare tooling, feeder cleaning, and recovery steps for jams or mispicks. |
