... the welding manipulator has many types:light duty type(LHQ),medium duty(LHZ), heavy duty(LHW), and ... stucture:stationary , stationary and revolve, moving and revolve*Cross-section of boom and column is calculated scientifically. ... ratchet6 structure, safe and reliable.*Boom end has cross-slides,which can be controlled thru manual pendant* ... of trolley rail mm1000 Light duty type auto welding manipulator