I will start this multi-post deckbuilding experiment by looking at the colorless artifacts in my Mirrodin selection pulled from a tournament pack and five booster packs.
I have the following artifact creatures:
Clockwork Beetle [starts at 2/2 for 1 but can only last a few turns of attacking and blocking]
Myr Retriever [a keeper because I can get another artifact of my choice out of the graveyard when this one dies]
Alpha Myr [2/1 for 2 is OK]
Myr Adapter [1/1 for 3 but gets a +1/+1 for each equipment attached, which is not bad]
2 of Yotian Soldier [1/4 with what effectively is Vigilance....quite close to a wall]
Cathodion [3/3 for 3 and adds to mana pool when it dies, I am playing it]
2 of Dross Scorpion [3/1 for 4 isn't great, although I could find that untap ability useful]
3 of Goblin War Wagon [3/3 for 4 and 2 more to untap makes this card barely playable]
Clockwork Condor [Starts as a 3/3 for 4 but goes to zero by itself when blocking and attacking]
Goblin Dirigible [4/4 for 6 and 4 more to untap means I play it if I have no choice]
Pentavus [5/5 for 7 and can use to generate tokens. It reads like a junk rare...maybe I am not understanding this card]
Myr Enforcer [4/4 for 7 but has affinity: play it]
For the artifact equipment:
Bonesplitter [OK yield of +2/+0 for 1 drop and 1 equip]
Golem-Skin Gauntlents ["for each" is a keeper]
Leonin Scimitar [OK yield similar to Bonesplitter]
Dead-Iron Sledge [Reads like a junk rare at uncommon...I am not seeing an advantage]
Neurok Hoversail [Flying for 3 is not that great, but a keeper for green decks]
Slagwurm Armor [0/6 for 4 is not terrible as a one-drop]
2 of Vulshok Gauntlets [OK yield of +4/+2 for 5]
Mask of Memory [OK for a blue deck]
Vorrac Battlehorns [trampled and multiple blocking: keep]
Vulshok Battlegear [+3/+3 for 6 is OK]
The colorless selection at this point does not allow me to build a deck.
16 artifact creatures
11 artifact equipment
33 total cards is well below 51 for a complete 60 card deck and a 15 card sideboard assuming 24 lands. I have never played a completely colorless deck. I guess I can use mana of any color!!!
Because I know there are many more cards I will be adding, of the 16 artifact creatures I would like to play 6:
1-drop: Clockwork Beetle
2-drops: Myr Retriever and Alpha Myr
3-drops: Myr Adapter and Cathodion
7-drop: Myr Enforcer
I am keeping all equipment except Dead-Iron Sledge (10 out of 11). I don't see the benefit of playing Tel-Jilad Stylus or Liar's Pendulum. I can find use for the other 4.
Final Tally: keep 6 of 16 artifact creatures, 10 of 11 artifact equipment, and 4 of 6 artifacts.
There is also this keeper:
Next, I add White (click on this link to get there)