Requires

Animation Module must be on the battlefield. Mana Echoes must be on the battlefield. Railway Brawler must be on the battlefield. You have a way to put a +1/+1 counter on a creature you control. Mana needed:

Steps

1. Put a +1/+1 counter on any creature you control.
2. Animation Module triggers, causing you to pay to create a 1/1 Servo artifact creature token.
3. The Servo enters the battlefield, triggering Mana Echoes and Railway Brawler
4. Resolve the Mana Echoes trigger, adding at least .
5. Resolve the Railway Brawler trigger, putting a +1/+1 on the Servo.
6. Animation Module triggers, causing you to pay to create a 1/1 Servo artifact creature token.
7. Repeat from step 3.

Results