For the record, I've only advanced the Automatron quest to the point of having ADA join me, nothing else.
You have to find the mods on other robots before you can build them.
Before You finish the DLC, almost all of the Robot Mods need to be looted before They are available. I have had a character get almost a complete Sentry, and a complete Robobrain before finding Assaultron legs to place on Ada. You do not need many Perks to assemble a Robot with found parts, the Perks are required to create new parts and to upgrade existing Robots. I have given Codsworth a full set of Armor and I may play with Curie when I get My current character ready for Wasteland Workshop.
You should really just finish the quest, all things will be revealed.
Yeah, I know. I'm really poking along here. The problem is I started a whole new character specifically designed for this, so I have a lot of character building I'm trying to get done before I actually dive in. Also, since my last post, I made my way much farther east and I've run into a few mobs of robots. Now I'm understanding how it all works. I had no idea about the raiders wearing the robot gear (sorry, I forgot their name), that was a cool twist.
Ah, good. Thanks for clearing that up.