Noncreature Artifact with MV<=1 in your graveyard.
All other permanents on the battlefield.
Steps
Activate
Salvaging Station by tapping it, returning the noncreature artifact with mana value 1 or less from your graveyard to the battlefield.
When the noncreature artifact enters the battlefield,
Weapons Manufacturing and
Grinding Station trigger.
Resolve the
Grinding Station trigger, untapping it.
Resolve the
Weapons Manufacturing trigger, creating a Munitions artifact token.
When the Munitions token enters the battlefield,
Grinding Station triggers, untapping
Grinding Station.
Activate
Clock of Omens by tapping the noncreature artifact returned in step 1 and the Munitions token, untapping
Salvaging Station.
Activate
Grinding Station by sacrificing the noncreature artifact.
Repeat.
Notes
You can sacrifice the Munitions to get infinite damage if desired. To do this, perform step 6 and sacrifice the Munitions token before resolving the untap ability in step 5. If the noncreature artifact chosen can sacrifice itself without tapping or additional costs, you can omit the sacrifice outlet, but will forego the possibility of infinite damage.