The rotational speed of the spray robot's cup is a significant factor affecting the fineness of the atomized mist. When other process parameters remain unchanged, the higher the rotational speed of the cup, the smaller the diameter of the paint droplets. Within a slightly lower speed range, the impact of the rotational speed on the fineness of atomization is notably greater than in the high-speed range.

The rotation speed of the spin cup on the spraying robot affects the film thickness. A low rotation speed can lead to a rough coating; on the other hand, too fine atomization can result in paint mist loss (over-spraying), causing fluctuations in the film thickness. Additionally, the spray booth is highly sensitive to any air currents when the atomization is fine. An excessively high rotation speed of the spin cup not only causes over-spraying but also leads to excessive wear on the turbine bearing, increases the consumption of compressed air for cleaning, and reduces the solvent content in the coating. The rotation speed of the spin cup on the spraying robot should be determined based on the flow rate characteristics of the coating used, hence the rotation speed for surface tension-based water-based coatings and high-viscosity two-component coatings is higher than that for standard solvent-based coatings.

The spray robot typically operates at an unloaded cup rotation speed of 6X10^4 r/min, with a set speed range of (1.0~4.2)X10^4 r/min under load, with an error tolerance of ±500 r/min.