Combat robotics

[Mecejide]

Combat robot capsules are made using combat robots, which can also be placed a roboport, and will attack any aliens that enter its construction range. These robots have infinite lifespan, but the defenders require ammunition taken from the repair pack slots of the roboport, and the distractors use more energy than logistic or construction robots to charge, with destroyers using even more.
3x electronic circuit + 1x pistol = defender robot
1x defender robot + 3x piercing rounds ammunition = defender capsule
3x advanced circuit + 1x battery = distractor robot
3x distractor robot = distractor capsule
3x battery + 1x flying robot frame = destroyer robot
5x destroyer robot = destroyer capsule

[BlueTemplar]

Not exactly what you were asking for, but you might be interested by Robot Army :
https://mods.factorio.com/mod/robotarmy