Because the sun equipment in a hybrid unit is pre-aligned within the gearhead rather than affixed to the motor shaft, these gearheads can be utilized in contouring applications such as a glue-dispensing nozzle for affixing a windshield to an automobile. Motion of the nozzle as it follows the seam between a windshield and its own window frame must be perfectly smooth; otherwise a ripple in velocity alters the bead diameter and causes messy glue software.

Smooth motion, this means the absence of torque and velocity variations (ripple), is essential in contouring applications. But, it really is difficult to consistently achieve smooth motion where the sun equipment is mounted on the motor shaft. Even a slight misalignment in the sun gear (electric motor shaft runout or coupling inaccuracies) could cause rough procedure and noise.

Many servo controllers use software compensation, and their success depends upon knowing the lost motion of the entire system. This info is usually obtainable from the gearhead manufacturer.
Contouring applications usually involve end-effectors or tool-points that adhere to mathematically defined paths. Sealant and bonding devices, water and flame cutters, laser welders and cutters, movement controlled cameras, and CNC machine tools are good examples.

Software compensation is accomplished by commanding the engine to move beyond the apparently desired position by a quantity equal to the system’s dropped movement, thereby bringing the strain to the truly desired position. For instance, consider a servomotor, gearhead, and leadscrew mixture in a pick-andplace robot. If 100,000 encoder counts equals 1.0 in. of linear motion and the system has 0.1-in. dropped motion, then your controller tells the motor to go 110,000 encoder counts to obtain 1.0 in. of motion, thus compensating for the 0.1-in. lost motion.

servo motor gear reducers backlash is the extra space between two adjacent equipment teeth and its own engaging tooth; lost movement is the total looseness or movement at a reducer’s output shaft when the input shaft is fixed. Dropped motion contains backlash, plus losses from bearing looseness, tolerances and fits, and shaft and equipment tooth compliance.
Servo controllers could be programmed to compensate for backlash and lost movement in planetary gearheads. This system compensates for backlash also where an application requires accuracy much better than the minimal backlash of the gearhead.