Plastic Gear 8T is a kind of gear drives. It usually works with motor shaft as a drive mechanism. There is interference fit between Plastic Gear 8T and motor shaft, therefore the gear should be pressed into the motor shaft with effort while assembling, and has to be disassembled by nut wrench according to the building samples. If the gear has to bear great load and be connected with motor shaft tightly, you need to use glue such as 502 glue.