1. A system for teaching how to weld which allows training of welder trainees from qualified experienced welders comprising: a base ( 2 ); an upper platform ( 4 ) positioned above said base ( 2 ); six actuators ( 3 ) extending between and connected to said base ( 2 ) and said upper platform ( 4 ) to allow said upper platform ( 4 ) to be moved in six degrees of freedom; a fixed bench ( 5 ) positioned above said base ( 2 ), said fixed bench ( 5 ) having a surface ( 6 ) on which a plate to be welded is mounted, said upper platform ( 4 ) defining an opening for access to the surface ( 6 ) on which the plate to be welded is mounted; an adaptor ( 7 ) connected to said upper platform ( 4 ); a welding gun ( 9 ) having a handle ( 10 ) connected to said adaptor ( 7 ), said welding gun ( 9 ) having a tip with an electrode ( 8 ) positioned adjacent to the plate to be welded, said plate being attached to the surface ( 6 ) of said fixed bench ( 5 ); a sensor ( 11 ) and a controller ( 12 ) connected to said actuators ( 3 ); an interface ( 13 ) connected to said sensor ( 11 ) and said controller ( 12 ); and a processor ( 14 ) connected to said interface ( 13 ), said processor ( 14 ) having a memory ( 15 ) and an alarm ( 16 ).