Motor

Overview
Used in the creation of things that require a motor.

Website Description
I prefer walking when it comes to transport. Less chance for accidents. But to each their own!

Used to Craft
Rotor + Stator + Assembler

Speculation
Probably used in the creation of Explorer, Miner, Constructor, and Assembler. There's a "work bench" in the preview video which has been guessed to be where your 'first' motors come from which you then later use to automate the creation of them.