You control at least one creature with one or more +1/+1 counters on it.
You control at least one other creature.
Mana Cache has at least one charge counter on it.
Thornbite Staff attached to Xavier Sal.
Xavier Sal does not have summoning sickness.
Steps
Activate Xavier Sal's second ability by tapping it and sacrificing a creature.
When the creature dies, Xavier Sal triggers, untapping Xavier Sal.
Resolve the Xavier Sal ability from step 1, putting a +1/+1 counter on a creature you control and a charge counter on Mana Cache.
Animation Module triggers, holding priority, activate Mana Cache by removing a charge counter from it, adding ({C} magic symbol) .
Resolve the Animation Module trigger, causing you to pay ({1} magic symbol) to create a 1/1 Servo artifact creature token.
Repeat.
Once you have infinite +1/+1 counters among creatures you control, you may instead use Xavier Sal's first ability to get infinite copies of creature tokens you control.