Nesting Bot

Start your engines! (If you have no speed, it starts at 1. It increases once on each of your turns when an opponent loses life. Max speed is 4.)
When this creature dies, create a 1/1 colorless Servo artifact creature token.
Max speed — This creature gets +1/+0.

Plains

Hangarback Walker

This creature enters with X +1/+1 counters on it.
When this creature dies, create a 1/1 colorless Thopter artifact creature token with flying for each +1/+1 counter on this creature.
{1}, {T}: Put a +1/+1 counter on this creature.

Mendicant Core, Guidelight

Mendicant Core's power is equal to the number of artifacts you control.
Start your engines! (If you have no speed, it starts at 1. It increases once on each of your turns when an opponent loses life. Max speed is 4.)
Max speed — Whenever you cast an artifact spell, you may pay {1}. If you do, copy it. (The copy becomes a token.)

Perilous Snare

Start your engines! (If you have no speed, it starts at 1. It increases once on each of your turns when an opponent loses life. Max speed is 4.)
When this artifact enters, exile target nonland permanent an opponent controls until this artifact leaves the battlefield.
Max speed — {T}: Put a +1/+1 counter on target creature or Vehicle you control. Activate only as a sorcery.

Built to Last

Target creature gets +2/+2 until end of turn. If it's an artifact creature, it gains indestructible until end of turn. (Damage and effects that say "destroy" don't destroy it.)

Ornithopter

Unctus, Grand Metatect

Other blue creatures you control have "Whenever this creature becomes tapped, draw a card, then discard a card."
Other artifact creatures you control get +1/+1.
{U/P}: Until end of turn, target creature you control becomes a blue artifact in addition to its other colors and types. Activate only as a sorcery. ({U/P} can be paid with either {U} or 2 life.)

Tamiyo's Logbook

{5}{U}, {T}: Draw a card. This ability costs {1} less to activate for each other artifact you control.

Glass Casket

When this artifact enters, exile target creature an opponent controls with mana value 3 or less until this artifact leaves the battlefield.

Thran Spider

Reach
When this creature enters, you and target opponent each create a tapped Powerstone token.
{7}: Look at the top four cards of your library. You may reveal an artifact card from among them and put it into your hand. Put the rest on the bottom of your library in a random order.

Machine Over Matter

This spell costs {1} less to cast if you control an artifact creature.
Return target nonland permanent to its owner's hand.

Guidelight Pathmaker

Vigilance
When this Vehicle enters, you may search your library for an artifact card and reveal it. Put it onto the battlefield if its mana value is 2 or less. Otherwise, put it into your hand. If you search your library this way, shuffle.
Crew 2

Island

Steel Overseer

{T}: Put a +1/+1 counter on each artifact creature you control.

Lonely Arroyo

This land enters tapped.
When this land enters, it deals 1 damage to target opponent.
{T}: Add {W} or {U}.

Sunscorched Desert

When this land enters, it deals 1 damage to target player or planeswalker.
{T}: Add {C}.

Deduce

Draw a card. Investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this token: Draw a card.")

Torrential Gearhulk

Flash
When this creature enters, you may cast target instant card from your graveyard without paying its mana cost. If that spell would be put into your graveyard, exile it instead.

Metallic Rebuke

Improvise (Your artifacts can help cast this spell. Each artifact you tap after you're done activating mana abilities pays for {1}.)
Counter target spell unless its controller pays {3}.

Guidelight Synergist

Flying
This creature gets +1/+0 for each artifact you control.

Tinker's Tote

When this artifact enters, create two 1/1 colorless Gnome artifact creature tokens.
{W}, Sacrifice this artifact: You gain 3 life.

Salvation Engine

Other artifact creatures you control get +2/+2.
Whenever this Vehicle attacks, return up to one target artifact card from your graveyard to the battlefield.
Crew 6

Whirler Rogue

When this creature enters, create two 1/1 colorless Thopter artifact creature tokens with flying.
Tap two untapped artifacts you control: Target creature can't be blocked this turn.

Cryptic Coat

When this Equipment enters, cloak the top card of your library, then attach this Equipment to it. (To cloak a card, put it onto the battlefield face down as a 2/2 creature with ward {2}. Turn it face up any time for its mana cost if it's a creature card.)
Equipped creature gets +1/+0 and can't be blocked.
{1}{U}: Return this Equipment to its owner's hand.

Voyager Quickwelder

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

Patchwork Automaton

Ward {2} (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {2}.)
Whenever you cast an artifact spell, put a +1/+1 counter on this creature.