How do I choose the right payload for a robotic arm?
Payload selection starts with the total load attached to the wrist: the workpiece, gripper, adapters, sensors, and other supported equipment. The advertised payload is not simply the maximum product weight. A heavier or longer tool can consume a significant part of the available capacity.
What this means in practice
Load distribution also matters. Consult the manufacturer's load diagrams and limits for the center of gravity, inertia, and tool moments. Acceleration, mounting orientation, and the process can affect permissible operation. Select a model using the actual tooling and motion conditions rather than relying on a single payload number.
Mass, leverage, and rotational loading
Two tools with the same mass can load a wrist differently if their centers of gravity are at different distances from the flange. Distribution of mass also affects rotational inertia, which matters when the tool changes orientation. A load check therefore needs more information than a scale reading.
Prepare loaded and unloaded configurations, including adapters, sensors, and any supported dress equipment. Use the manufacturer's load limits and configuration instructions for the exact robot. Allow for documented process variation, but do not treat an arbitrary payload margin as a substitute for checking the actual load geometry.
Key points
Weigh every supported component, including adapters and sensors.
Calculate the combined center of gravity for loaded and unloaded states.
Verify the proposed load and motion against the manufacturer's limits.
Practical example and next step
As an illustrative calculation, a 3 kg component and a 2 kg tool create at least 5 kg of carried mass before additional attachments. That calculation is only a starting point; it does not prove a 5 kg-rated arm suits the application's load distribution or required cycle.