The PBA 500, PBA 500+, and PBA 600+ models are all driven by servo motors and do not require hydraulic oil. Instead, a small amount of lubricating oil is used for maintenance.
In contrast, the PBA 600, PBA 1000, and PBA 1000# models use a hydraulic cylinder to drive the Y axis and require 46# anti-wear hydraulic oil. Specifically, the PBA 1000 and PBA 1000# models use 250 liters of oil.