Edited 9/23/16 based on ideas from you guys and a few ideas I had myself.
Swapped out Stoic Rebuttal for Chief Engineer. I feel like 4 counterspells isn't enough to justify their presence in the main, could be a solid sideboard card at the risk of making the deck slower.
Switched Panharmonicon for Mox Opal. The Panharmonicon looked like a great idea because i originally built the deck to gain a lot of life with Filigree Angel but I got tired of losing.
Make everything cheaper!Ideal turn 1: Darksteel Citadel, Mox Opal, Etherium Sculptor and Ornithopter
Turn 2: Land, Master Transmuter
Turn 3: Land, transmute Sphinx Summoner, fetch Blightsteel Colossus
Turn 4: land, Transmute Blightsteel Colossus, start winning
Otherwise, turn 1 is Darksteel Citadel, as many of Ornithopter/Memnite as you can play, Mox Opal, Chief Engineer
turn 2 is land, Mox Opal, convoke into Master Transmuter AND Sphinx Summoner, fetch Blightsteel Colossus (the math on this only works out if you draw first, and you have to have four 0 cost creatures available)
turn 3 transmute into blightsteel colossus and win.
Can it work? Yep. I recognize that it won't work every time, and while it can work as early as turn three it's probably unusual for this deck to reliably play a Blightsteel Colossus before turn 5.
