The latest version of is type of GMAW is called: "SpinArc" and is produced by a company named "WELDREVOLUTION"...
One of the biggest differences between what is shown in the link from fschweighardt and "SpinArc" is the simplicity of the improved torch system... Another big difference is the fact that the "SpinArc" torch: No gears and no lubrication required...
The first generation of this process were known as Rotating Electrode GMAW or (RE)GMAW and (RLT)GMAW = Rotating Lead Tandem... If one reads the article from the Journal of Ship Production May 2005 there are visual and engineering differences between the (RE)&(RLT))GMAW torches. Now I'm not going to go through a long winded comparison between the 2 versions of these GMAW torches other than to add that both are mechanized and were used with a robot via TTA seam tracking, or compare the latest version known as the "Spin Arc" (RE)GMAW torch because I need to do some other stuff around the apartment and I get tired easily from typing these days... So I'll end by referring everyone to the new (RE)GMAW mechanized torch described in these links below:
http://www.weldrevolution.com/Make sure you read the articles, the video's, productivity studies and the technical presentation & brochure below in this link:
http://www.weldrevolution.com/support/http://www.youtube.com/weldrevolutionEnjoy the reading and videos.
Respectfully,
Henry