When high dynamic responses are required, engineers need to carefully tune the servosystems, preferably with loads attached, for the most responsive performance. Tuning can provide faster moves and minimize spongy motion while reducing overshoot or ringing after moves are complete.
Designers must also pay attention to radial-load and axial-thrust-load specifications. Axial-thrust load is the force acting along the output-shaft axis; radial load acts perpendicularly to the output shaft.
The force of gravity acting on the load is perhaps the most common source of radial loads, but other sources are possible, depending on the mechanical apparatus attached to the output shaft. Additional external bearings may be required with some loads to minimize these forces and prolong the life of the gearbox’s internal bearings.
A common way to minimize backlash is to approach all target positions from a common direction. In the event a reversing move is required, some designers let the load go past the desired position and return to it from the common direction.