Activate Iron Spider by tapping it, putting a +1/+1 counter on each artifact creature and/or Vehicle you control.
Activate Cryptic Trilobite by removing a +1/+1 counter from it, adding {C}{C} that can only be spent to activate abilities.
Activate Voltaic Construct by paying {2}, untapping Iron Spider.
Repeat.

Infinite +1/+1 counters on artifact creatures you control

Iron Spider, Stark Upgrade

Voltaic Construct

Cryptic Trilobite

Activate Iron Spider by tapping it, putting a +1/+1 counter on each artifact creature and/or Vehicle you control.
Activate Workhorse and Crystalline Crawler by removing a +1/+1 counter from each of them, adding {1}{C}.
Activate Voltaic Construct by paying {2}, untapping Iron Spider.
Repeat.

Combos with "Iron Spider, Stark Upgrade"