A coating system (10) for forming a protective layer includes a roller
mechanism (34) provided at an end of an arm (46) of a robot (16a) as an
end effector. The roller mechanism (34) has a roller (48), a holder (86)
for supporting the roller (48), and a pipe (112). The holder (86) is
removably attached to the roller (48). The pipe (112) supports the roller
(48) in a freely rotating manner, and delivers the protective layer
forming material to the roller (48).