The advantages of using ball bearings

 A metal bead work belongs to the point of contact, the activation is easy to operation

 B can be used in often in a different Angle and direction implantation operation of portable products (but to prevent breaking or falling)

 C a longer service life (compared to oil bearing)

 With ball bearing faults

 A bearing structure is quite fragile, cannot withstand the impact of external forces

 B motor turns, the rolling of metal bead will produce large noise

 C price is high, can't compete with oil bearing on the cost price

 D ball bearing the source and quantity of demand, is not easy to control

 E use ball bearing of the elasticity of the spring to its positioning, assembly is not easy