Evaluate the robot at the worst point in the real cycle.
A product may weigh 20 kg, but the robot might carry another 15 kg of gripper, valves and mounting hardware. If that mass projects a long distance from the wrist, the resulting moments and inertia can limit acceleration or make a nominally large robot unsuitable.
Reach also needs context. The tool centre point must approach every position with the required orientation while avoiding the machine, fixtures, guarding and the robot's own singular or restricted regions.
Total moving mass
Combine the heaviest product, all tool hardware and any services carried by the wrist.
Centre of gravity
Measure the combined load relative to the robot mounting face in each relevant tool configuration.
Usable envelope
Check approach paths, wrist orientation, inner limits, vertical range and collision clearance.
Complete cycle
Include machine dwell, grip confirmation, image processing, conveyor availability, release and fault margin.
Specification term versus production reality
Use published data to create a shortlist, then verify the shortlisted system against the application.
| Rated payload | Maximum permitted mass under defined conditions | Must include tool and product; wrist moments and inertia still apply |
|---|---|---|
| Maximum reach | Furthest nominal point in the working envelope | Does not guarantee approach angle, path clearance or performance at that point |
| Repeatability | Ability to return consistently to a taught position | Not the same as absolute accuracy or process capability |
| Cycle figure | Often measured using a defined or unloaded test motion | Real output includes tooling, product flow, process time and line constraints |
| Protection rating | Published enclosure resistance for defined robot parts | Tool, cabling, controller and complete cell must suit the environment too |