Count by fives
Frames are manufactured in multiples of 5 segments, which for 40mm wide frame results in lengths of 200 mm or approximately 7.5 inches. Frames of two, three, and four segment lengths are included to allow for the construction of additional joints and assemblies.
Frame lengths are intentionally limited to 2, 3, 4, 5, 10, 15, 20, 25, and 30 holes per side. These lengths have been chosen to allow for the creation of all necessary joint configurations (using lengths 2, 3, 4, and 5) as well as to allow for lengths with a center hole and lengths which are evenly divisible by two. The reduced set of lengths allows for improved reuse from project to project, easier identification in photographs and diagrams, and simpler production, handling, and shipping.