Activate Goblin Welder by tapping it, causing you to sacrifice Sewer-veillance Cam and return another artifact from your graveyard to the battlefield.
Sewer-veillance Cam triggers, untapping Goblin Welder.
Activate Goblin Welder by tapping it, causing you to sacrifice the artifact returned in step 1 and return Sewer-veillance Cam from your graveyard to the battlefield.
When Sewer-veillance Cam enters, it triggers, untapping Goblin Welder.
Repeat.

Infinite ETB

Infinite LTB

Infinite death triggers

Infinite recursion of artifact creatures you control

Infinite sacrifice triggers

Goblin Welder

Sewer-veillance Cam

Activate Emry by tapping it, allowing you to cast Sewer-veillance Cam from your graveyard this turn.
Activate a creature by tapping it, adding at least {U}.
Cast Sewer-veillance Cam from your graveyard by paying {U}.
When Sewer-veillance Cam enters, it triggers, untapping Emry.
Activate Krark-Clan Ironworks by sacrificing Sewer-veillance Cam.
Sewer-veillance Cam triggers, untapping the mana-producing creature.
Repeat.

Infinite colorless mana

Infinite storm count

Emry, Lurker of the Loch

Krark-Clan Ironworks

Activate Emry by tapping it, allowing you to cast Sewer-veillance Cam from your graveyard this turn.
Cast Sewer-veillance Cam from your graveyard by paying {U}.
When Sewer-veillance Cam enters, it and Grinding Station trigger.
Resolve the Sewer-veillance Cam trigger, untapping Emry.
Resolve the Grinding Station trigger, untapping it.
Activate Urza's first ability by tapping Sewer-veillance Cam, adding {U}.
Activate Grinding Station by tapping it and sacrificing Sewer-veillance Cam.
Sewer-veillance Cam triggers, untapping a creature you control.
Resolve the Grinding Station ability.
Repeat.

Cast all spells in your library

Exile your library

Infinite blue mana

Infinite mana creatures you control can produce

Infinite mill

Infinite self-mill

Infinite untap of creatures you control

Infinite card draw

Infinite draw triggers

Urza, Lord High Artificer

Grinding Station

Activate Vhal by tapping it, adding at least {C}{C}{C}{C}{C} that cannot be spent to cast spells from your hand.
Activate Chrome Dome by paying {5}, creating a token copy of Sewer-veillance Cam.
When the Sewer-veillance Cam token enters, it triggers, untapping Vhal.
Repeat.

Infinite colorless mana that can't be spent to cast spells from your hand

Chrome Dome

Vhal, Candlekeep Researcher

Combos with "Sewer-veillance Cam"