I agree w/ the above, having an artificer is actually kind of freeing for the DM I've found. I'd also be generous about letting him have a Dedicated Wright that does his work, either just at camp (it doesn't need to sleep), in a portable hole, or even at home once they get easy teleport-type travel options. That kills the downtime aspect of the character, and making that hard is tantamount to saying "please don't play an artificer."
The only concern that comes to mind, barring a few shenanigans based on tenuous readings of the rules which doesn't seem to be an issue w/ your player, is that artificers can require some out of game time to play w/ all their bookkeeping (a trait they share w/ summoners). I'd suggest doing as much of that between sessions as possible, making allowances for the occasional situational thing -- e.g., let's scribe some scrolls of fire resistance before we forge into the dragon's lair. Other players can be helpful in this regard, too, like that fighter can (in and out of character) talk about what sort of shiny thing he'd like.
Depending on how into clockwork creations and rules you and the player are, I'd also suggest the Craft Effigy feat (CArc) -- it's totally balanced assuming you don't layer templates on them, which you obviously shouldn't. A lot of constructs that you can make w/ Craft Construct are a pain, like golems. There's also a thread called the Mechonomicon lying around which has a bunch of neat oddities listed in it. That's some levels down the line, but there it is.