this customer bought two Fulzh robots. the are manufacturer of steel structure. the plate thickness is 20mm so robot need weld several time for one weld seam.
We have arc sensor for big thickness work piece. with arc sensor, you need just program one time then robot will weld one seam again and again.
In this system, one robot was connected one positioner, the positioner is two axis, so the complete system is 8 axis.