Deck Summary

This deck is primarily focused on mill, both self-mill and milling opponent's libraries.  For your starting hand you should be aiming to have a draw effect in hand and hopefully a mill card in hand as well, or two of either would be fine as well.  Additionally you'll want a ramp card in your opening hand too.  Your goal for the first couple of turns is to ramp and start thinning your library.  Turn 2/3 hopefully you'll have drawn or milled a protective equipment piece for Osgir, the Reconstructor, but if not keep thinning your deck to find one.  In general on turn 3/4 you'll want to get Osgir onto the field, ideally you'll be able to suit him up with a hexproof equipment or Commander's Plate on that turn or the turn after.  Once you've managed to get Osgir bunkered down, start using his ability to recur artifacts out of the graveyard.

Your win condition is primarily going to be Grinding Station in the mid to late game combined with ways to untap Osgir.  Second to that you'll probably end up falling back on Hellkite Tyrant.  A tertiary strat is to go for single player eliminations.  This is feasible through Aetherflux Reservoir and combat damage. In the mid and late game don't underestimate the power of Osgir, the Reconstructor's sacrifice ability.  The extra two power for one mana that ability provides can go a long way towards commander damage player eliminations at later stages in a game.  This combined with Seize the Day and adding in an equipment like Sword of Vengeance for some evasion can result in a turn of multiple combats with each combat phase yielding 21+ commander damage.

Some deck techs 

Mycosynth Lattice and overloaded Vandalblast for an asymmetrical complete board wipe.  Hopefully you still have friends in the pod afterwards.

Altar of the Brood with Lands and Osgir's ability every turn to mill opponents of lots of cards

Mesmeric Orb to mill lots of cards

Grinding Station to mill lots of cards from yourself then lots of cards from your opponents when you can have a big turn.  

Hellkite Tyrant as an alternate win condition.  Emergence Zone with 8 mana available can be a sneaky way to get this onto the board before your upkeep.

Platinum Angel - a way to hang in there.

Codex Shredder - this is obviously a way to thin your deck via self mill, but don't underestimate the power of being able to get a card back from the graveyard.  If you mill that Hellkite Tyrant it's not necessary gone for good.

Glasses of Urza - I place a high value on understanding what interaction is available to my opponent's, but definitely swap this card out if that's not your style.

Aetherflux Reservoir as an alternate win condition - if you have two of them due to Osgir then you can get a lot of health by casting a lot of cards through utilizing Osgir's ability to get more artifacts out of the graveyard that draw more cards.  You can at the very least eliminate a player with this card.

Another alternate win condition is commander damage via the protection cards Commander's Plate, Mask of Avacyn, Conqueror's Flail, Champion's Helm, and the untap card Umbral Mantle.  You can even add in combat tricks from the likes of Veteran's Reflexes and Wings of the Cosmos to get an extra damage if necessary.  Also don't forget that Osgir's ability allows him to sacrifice an artifact to get +2/+0 more damage.

Use the the stax pieces of Tangle Wire, Winter Orb, and Meekstone when appropriate.  Winter Orb you'll probably want to cast early on, but make sure to keep 1 mana open so that you can sacrifice it with Osgir before it becomes your turn.  Then after your upkeep you can use his ability again to recurr two of them from the graveyard.  Meekstone you'll likely want out early as well, but you'll also probably want to remove if you get to a point where Osgir can start dealing 21 commander damage.  Recurring Tangle Wire will cause 8 permanents to be tapped by your opponents and 6 by you on the first go around.  Forcing lots of tapped resources is also a really good stax piece to have out when you're ready to start giving opponents a beat down, just make sure you have enough artifacts and lands to tap so that it doesn't impact your current momentum.

One other consideration is trying Mirror of Fate, I tried to find an infinite loop based on this card and getting back things exiled by Osgir, but unfortunately I couldn't find a way to get enough mana and card draw.  Seems like there is potential here, but I haven't found all the pieces yet.  Maybe one day.