"Alright, you're back just in time. Do you think you would be able to help me out again? I will totally make it worth your while. So here is the thing, Lt. Gerry is still trying to make his super bot, so I want to make myself a little something to fight his super bot. I need you to bring me back at least 30 atta heads, and then 50 of those bot arms, and finally I need one of those glowing energy cells at the bottom of those giant stalkers. That should do it."
The first three components should be easy enough to find.
Atta Heads at the local hive, Bot Arms around the Robotic Facility and you bump into Stalkers all over the map, on roads near CPs etc. Juggernauts on the other hand are not as common in Incline. A good place to start looking for one is around: 110,345