Roboticist

Being Dr. Light
You're a roboticist! Half engineer, half doctor, all badass. You spawn in the assembly line, and must defend it from those seeking your flashes and energy cells. You have three primary responsibilities, which include making cyborgs, making mechs, and making robots.

Cyborgs
Use your robot fabricator to make a cyborg frame and a head, left and right arm, torso, and left and right leg. Put two flashes in the head, then put wires and a (small) power cell into the torso. Attach everything to the frame. Get a brain, shove the brain into an MMI, shove the MMI into the body. Done!

Mechs
Someone else do this, I don't play with these useless piles of junk. Consult the book in game for all the info you need

Robots
This is the FUN part!

Medbot
Empty out any medkit, the color will remain. Use a robot arm on the medkit. You can name the assembly by clicking it with a pen. Attach a health analyzer, and then a proximity sensor.

Floorbot
Empy out a toolbox, attach a robot arm, use a pen to name, click it with a floor tile, attach the sensor.

Cleanbot
Attach a robot arm to a bucket, name with pen, click with proximity sensor. Securitron Screwdriver a remote signaling device, add that to a helmet, weld them, add a proximity sensor, add a robot arm, click with stun baton. ED-209 Build a cyborg frame from your fabricator, then use metal on it to reinforce it. Attach a left and right leg and an armor vest(go yip at security for one of these). Weld them, add a helmet, a proximity sensor, wires, a taser, and a power cell. Done.

Being Dr. Wily
Anything you build(besides mechs) can be emagged. Cyborgs will become loyal to you and you alone, and unlock a special weapon based on module. Floorbots will rip floors apart, medbots will inject toxins, cleanbots will wet floors, securitrons will cuff everyone, ED-209s will make a lot of noise and fire at walls long after whatever they're aiming at has gotten bored and walked away.