The other posters have really done justice to the idea. I'll say some more stuff that may help explain my thinking, but I think the core concept is already out there.
http://forums.ddo.com/showthread.php?t=355271 is a version that worked out really well (despite my skepticism in the build post). I can't speak highly enough of the combination of lightning enhancements, lightning motes and the storm dragonmarks.
The base concept was just that Flame Turret, Insightful Damage + Battle Engineer 1 can get me to cap easily. That requires level 7 Arti for the two different level 3 infusions. Given that, why not go 8 for the bonus feat. Given 8, why not go 9 to get motes and respectable Toven's lightning damage.
After that, to get another past life you need at least 9 levels of another class, and can play with a splash of 1 or 2 levels or a third class. The concept is far from prescriptive, though the Barb 1 splash is definitely a good option.
I should say though... it's not really an artificer - it's a build to pick up another class's Past-life without changing gear or playstyle from an artificer. You can't provide the raid party buffs (metal types of weapon) - much less functionality at cap - of a pure artificer.