Let's break down the deck grouping cards into sections with how they work and why.
Group A - Artifacts to grab with Arcum
*Planar Bridge - Really cool card for commander to grab anything out of your deck almost.
*Darksteel Forge - Makes your artifacts indestructible and makes it hard to kill your stuff.
*Paradox Engine - Untaps all your mana rocks with every cast, this can make you get some crazy combos.
*Caged Sun - Extra ramp to go crazy with mana.
*Ugin's Nexus - Stopping extra turn takers and maybe start taking your own extra turns to pull off a win.
*Mindslaver - Steal other players' turn.
*Myr Matrix, Myr Turbine - create fodder and build armies later in the game.
Group B - Fodder Cards and What not
*Junk Diver - Dies and returns another fodder piece, or returns an artifact that can be useful.
*Myr Retriever - Same as Junk Diver.
*Scrap Trawler - Probably one of the better fodder cards or you can keep him to loop with more fodder.
*Memnite and Ornithopter - Free creatures, and easy to kill off for better things.
*Solemn Simulacrum - Comes in get a land, dies get a draw.
Group C - Mana Dorks, Mana Rocks
*Silver Myr, Plague Myr, Manakin, Millikin
*Sky Diamond, Coldsteel Heart, Sol Ring, Mana Crypt
*Basalt Monolith, Grim Monolith, Mana Vault, Metalworker
Group D - Protection/Artifact Matter Cards
*Memnarch - Steal their artifacts or maybe their creatures.
*Padeem - stop all the targeting removal spells.
*Vedalken Archmage - Draw power from all the artifacts
*Muzzio, Visionary Architect - Dig through your top deck for artifacts.
*Master Transmuter - Trade artifacts on the field for bigger artifacts.
*Karn, Silver Golem - Make artifacts into big hitters.
*March of the Machines - Make artifacts into killers.
*Mechanized Production - Clone the artifacts into a swarm of power.
*Lightning Greaves and Neurok Stealthsuit - Protect Arcum or another creature.
Group E - Support Artifacts
*Unwinding Clock - Untap Rocks and Artifacts for more mana/blockers/etc.
*Crawlspace - Keep out wide attacks (Ensnaring Bridge can also work but I prefer Crawlspace).
*Spine of Ish Sah - Removal for the deck pretty much, Good cloning target as well.
*Mirrorworks - Cloning other artifacts is great in this type of deck.
*Nevinyrral's Disk - Board wipe, also a good cloning target.
Group F - Counter Spells/Removal/Bounce Cards
*Mana Drain, Counterspell, Stoic Rebuttal, Negate
*Cancel, Hinder, Cryptic Command, Rewind
*Muddle the Mixture, Pact of Negation
Engulf the Shores, Cyclonic Rift, Evacuation, Devastation Tide
Group G - Draw Power and Tutors
*Ponder - Easy 1 drop draw card.
*Reverse Engineer - Basic 2 drop Draw 3 cards.
*Fabricate - Found any card you might need at the time.
*Blue Sun's Zenith - With all the colorless mana in the deck you can draw a whole lot with this card.
*Whir of Invention - Find any artifact that you want smack it on the field.
Group H - Final fill in cards
*Metalwork Colossus and Blightsteel Colosuss - Killers and big boys that can wreck opponents.
*Tezzeret The Seeker - Tutors for Artifacts, untaps your Mana Rocks, and Wincon maybe.
*Ulamog, The Ceaseless Hunger - Comes out with the Planar Bridge and kills fast.
So ideally you want to build a field up with very strong artifacts using Arcum.
Now while play this you always want to build up from the ground with protection cards first like DarkSteel Forge or Lightning Greaves (For Arcum), then next you probably want to look for mana accel like Caged Sun, or Token generators like Myr Turbine.
Last you want to grab Planar Bridge or Paradox Engine then the other after that.
After that you can grab what you need at the given time.
So have fun, invent, and destory.