The man who designed Luke Skywalker's iconic lightsaber from "Star Wars" says it wasn't inspired by the Force, but came to him through sheer luck.

Oscar-winning production designer Roger Christian says he knew, back in 1977, that the lightsaber would be a key prop for George Lucas' untested space opera, "Star Wars." However, a tight budget made it difficult for him to come up with the right look.

"It's the Excalibur to King Arthur," Christian told CTV News Channel on Thursday, in explaining the pressure he felt over the design. "This would be the iconic image (of the film)."

But, while Arthur ended up pulling Excalibur from a stone, Christian says he pulled Luke's lightsaber out of an old box of parts at a photographer's shop.

Christian says he found what would become the base for the lightsaber "by sheer luck," in the first of a series of dusty boxes. Out came this graflex flash handle from the press cameras of the 40s," he said. "And I went, 'Oh, the holy grail! I found it!'"

Christian took the handle to his shop and added a few strips of rubber to the base, then presented it to Lucas as what would become the "Star Wars" franchise's single most iconic weapon. "He just held it in his hand and smiled, which is George's biggest sign of approval that you can ever have," he said.

That first lightsaber became more than just a prop as the franchise unfolded, serving as a proverbial "torch" passed from Anakin Skywalker in the prequels, to Luke in the original franchise, to the new protagonist, Rey, in "The Force Awakens."

Christian goes into detail about designing the world of "Star Wars," as well as his other projects, in a new memoir called "Cinema Alchemist: Designing Star Wars and Alien," in book stores now.