Perhaps the most apparent is to increase precision, which really is a function of manufacturing and assembly tolerances, gear tooth surface finish, and the guts distance of the tooth mesh. Sound is also suffering from gear and housing components and also lubricants. In general, be prepared to pay out more for quieter, smoother gears.
Don’t make the mistake of over-specifying the engine. Remember, the insight pinion on the planetary must be able deal with the motor’s result torque. What’s more, if you’re utilizing a multi-stage gearhead, the result stage must be strong enough to soak up the developed torque. Obviously, using a better motor than required will require a larger and more expensive gearhead.
Consider current limiting to safely impose limits on gearbox size. With servomotors, result torque is usually a linear function of current. So besides safeguarding the gearbox, current limiting 
also protects the engine and drive by clipping peak torque, which can be anywhere from 2.5 to 3.5 times continuous torque.
In each planetary stage, five gears are concurrently in mesh. Although you can’t really totally remove noise from such an assembly, there are many methods to reduce it.
As an ancillary benefit, the geometry of planetaries fits the form of electric motors. Hence the gearhead could be close in diameter to the servomotor, with the result shaft in-line.
Highly rigid (servo grade) gearheads are generally more low backlash gearbox costly than lighter duty types. However, for rapid acceleration and deceleration, a servo-grade gearhead could be the only sensible choice. In this kind of applications, the gearhead could be seen as a mechanical springtime. The torsional deflection resulting from the spring action increases backlash, compounding the effects of free shaft motion.
Servo-grade gearheads incorporate many construction features to reduce torsional stress and deflection. Among the more common are large diameter result shafts and beefed up support for satellite-equipment shafts. Stiff or “rigid” gearheads have a tendency to be the most costly of planetaries.
The kind of bearings supporting the output shaft depends upon the strain. High radial or axial loads usually necessitate rolling component bearings. Small planetaries can often get by with low-price sleeve bearings or additional economical types with fairly low axial and radial load ability. For bigger and servo-grade gearheads, heavy duty result shaft bearings are often required.
Like the majority of gears, planetaries make noise. And the quicker they run, the louder they obtain.
Low-backlash planetary gears are also available in lower ratios. Although some types of gears are generally limited by about 50:1 and up, planetary gearheads lengthen from 3:1 (solitary stage) to 175:1 or even more, depending on the number of stages.