There is nothing we could add to prepare you for this:
Here's the description from the YouTube page:
Enjoy what might be the most needlessly elaborate robot-assembly sequence ever animated. I can only assume that each robot section was sold separately as a toy, and that Water Bridge Segment 3 was big that Christmas.
This clip comes from Starbirds, the dubbed American movie version of the '70s TV anime known as Brave Leader Daimos. While 3-B edited down 44 episodes of Daimos into a single Starbirds movie, they kept the entire robot-transforming scene. Bravo.
Daimos is unavailable in North America, but you can find the cheap DVD release of Starbirds at depressing discount stores across the nation, and at severely inflated prices on Amazon.