Why arms are built to swap tools
A robot arm permanently fitted with one gripper can only do the class of tasks that gripper supports well. Given that no single gripper design handles every object and task, as the previous lessons established, a facility running varied production would need either a different arm for every tool type or a way to change tools on a single arm. Many industrial arms are built for the second option: a quick-change coupler mounted at the wrist lets the arm's tool-side half mate with a matching half on each gripper, so the controller can command the arm to dock at a tool stand, lock onto a different gripper, and resume work, often in a matter of seconds and without human intervention.
The mechanical half of this connection typically uses a standardized coupling, pins, cams, or a twist-lock mechanism, engineered to hold rigidly under the forces of normal operation while still releasing cleanly on command. The electrical half runs alongside it: a connector that passes through power for the gripper's actuator, signal lines for any sensors built into the gripper, and in some cases pneumatic or vacuum lines for suction tooling, all mating in the same docking motion as the mechanical lock. Because both halves are standardized across the gripper set, any compatible gripper can be picked up by the arm without custom integration for each one.