Plains

Etherium Sculptor

Artifact spells you cast cost {1} less to cast.

Port Town

As Port Town enters, you may reveal a Plains or Island card from your hand. If you don't, Port Town enters tapped.
{T}: Add {W} or {U}.

Swords to Plowshares

Exile target creature. Its controller gains life equal to its power.

Emry, Lurker of the Loch

This spell costs {1} less to cast for each artifact you control.
When Emry, Lurker of the Loch enters, mill four cards.
{T}: Choose target artifact card in your graveyard. You may cast that card this turn. (You still pay its costs. Timing rules still apply.)

Faerie Mastermind

Flash
Flying
Whenever an opponent draws their second card each turn, you draw a card.
{3}{U}: Each player draws a card.

Unwinding Clock

Untap all artifacts you control during each other player's untap step.

Island

Command Tower

{T}: Add one mana of any color in your commander's color identity.

Shorikai, Genesis Engine

{1}, {T}: Draw two cards, then discard a card. Create a 1/1 colorless Pilot creature token with "This creature crews Vehicles as though its power were 2 greater."
Crew 8 (Tap any number of creatures you control with total power 8 or more: This Vehicle becomes an artifact creature until end of turn.)
Shorikai, Genesis Engine can be your commander.

Arcane Signet

Fellwar Stone

{T}: Add one mana of any color that a land an opponent controls could produce.

Imposter Mech

You may have Imposter Mech enter as a copy of a creature an opponent controls, except it's a Vehicle artifact with crew 3 and it loses all other card types.
Crew 3

Lita, Mechanical Engineer

Vigilance
At the beginning of your end step, untap each other artifact creature you control.
{3}{W}, {T}: Create a 5/5 colorless Vehicle artifact token named Zeppelin with flying and crew 3. (It has "Tap any number of creatures you control with total power 3 or more: This Vehicle becomes an artifact creature until end of turn.")

Prairie Stream

({T}: Add {W} or {U}.)
Prairie Stream enters tapped unless you control two or more basic lands.

Foundry Inspector

Sol Ring

Generous Gift

Destroy target permanent. Its controller creates a 3/3 green Elephant creature token.

Seat of the Synod

Manifold Key

{1}, {T}: Untap another target artifact.
{3}, {T}: Target creature can't be blocked this turn.

Dispatch

Tap target creature.
Metalcraft — If you control three or more artifacts, exile that creature.