Born "Cutty Flam", Franky was orphaned as a young child, later taking the name Frank Heather. Taken in by Mill, he apprenticed as a starshipwright alongside his adopted brother Iceburg. Together they built ships and a family. Eventually the Imperial Hegemony discovered that Mill had created the True Hegemon's ship Ascension and tracked him down. Young Franky tried to stop the Legion ship sent to take Mill, in desperation and loss with his bare hands. He was crushed by the ship, losing most of his body in his futile attempt.
Now, a cyborg and living with gusto, he is ready to take the Firedrake and its crew to right the wrongs of the Hegemony.
Franky builds the crew a new boat and personalizes it by building a mini version of the crew's original boat, the Going Merry. This clip, although joyful and happy, doesn't quite capture the emotion as all One Piece watchers cried watching a cartoon boat (the original Going Merry) be destroyed. It's the inspiration for where Franky wants to customize the Firedrake for the rest of the crew.
Existence is not a sin.
Franky likes to dance.