To make his press brake, [Rupert] scavenged ... he was ready to bend some aluminum. One trick [Rupert] picked up is scoring the sheet metal on the inside of a future bend. For [Rupert]’s project ...

Here you can see him carefully lining the raw aluminum to the body of the car. He marks off the point where the metal should bend. Then, he uses the radius brake to get the desired bend.