End effector

An end effector is the device at a robot arm's working end that directly performs its task: for example, a gripper, welding tool or suction cup. The arm places and orients it, while the tool's geometry and contact behavior determine how that motion affects the object. A tool-tip frame can differ from the mounting-flange frame, so its offset must be included in forward kinematics.^[ref]

For example, suppose a two-finger gripper holds an object vertically by dry friction. If each finger applies normal force $N$ and the coefficient of friction is $\mu$, the ideal upward friction capacity is $2\mu N$. With $\mu =0.5$ and $N=10\mathrm{N}$ per finger, that capacity is $10\mathrm{N}$, just above the weight of a one-kilogram object near Earth's surface. A real test varies gripping force and load while observing slip; contact material, deformation and acceleration can invalidate the simple estimate. Positioning accuracy alone therefore does not establish grasp reliability.