Efficient Construction

Whenever you cast an artifact spell, create a 1/1 colorless Thopter artifact creature token with flying.

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.

Thopter Engineer

When this creature enters, create a 1/1 colorless Thopter artifact creature token with flying.
Artifact creatures you control have haste. (They can attack and {T} as soon as they come under your control.)

Stridehangar Automaton

Thopters you control get +1/+1.
If one or more artifact tokens would be created under your control, those tokens plus an additional 1/1 colorless Thopter artifact creature token with flying are created instead.

Thopter Fabricator

Flying
Whenever you draw your second card each turn, create a 1/1 colorless Thopter artifact creature token with flying.
Crew 2

Foundry of the Consuls

{T}: Add {C}.
{5}, {T}, Sacrifice this land: Create two 1/1 colorless Thopter artifact creature tokens with flying.

Saheeli, Radiant Creator

Whenever you cast an Artificer or artifact spell, you get {E} (an energy counter).
At the beginning of combat on your turn, you may pay {E}{E}{E}. When you do, create a token that's a copy of target permanent you control, except it's a 5/5 artifact creature in addition to its other types and has haste. Sacrifice it at the beginning of the next end step.