Use rekindle in your contraptions to quickly regenerate sections that you define only once. Rekindle will duplicate a section of your contraption at the angle, location and timing that you want.

In the example below, the arm of the conveyor is described only once, and is told to rotate 10 degrees. At the end of the 10 degrees, it's told to rekindle itself a total of 36 times (10 degrees x 36 arms = 360 degrees). Finally, it's told to rotate the remaining 350 degrees of a full circle.