When creating a drone army every second through factory, after few seconds, you run out of memory.
Proposal A
Add a "maximum alive drones : N" field to the factory, so the factory creates exactly N simultaneous drones
The factory, using a FIFO cycle, destroys the oldest drone (all remaining parts of the drone, if they exist) and create a new drone
Proposal B
Add a "destroy drones after X seconds" field to the factory, so the factory create temporary drones that are destroyed after X seconds
Proposal C
Add a "destroy drones after receiving event Z" field to the factory, so the factory all its drones after receiving event Z