# 14 Designing Oud Bowl Ribs: 3D Geometry, Taper & Alternative Materials (Carbon Fiber, Fiber Glass)

Episode 14 — Understanding the Oud Bowl: 3D Geometry, Alternative Materials & Rib Taper Calculations What makes the geometry of an oud bowl so complex, and how do we translate that geometry into individual ribs that can be shaped and assembled into a three-dimensional structure? In Episode 14, I explore the geometry behind the oud bowl, demonstrate how a two-dimensional inner bowl profile relates to its three-dimensional form, examine alternative materials for bowl construction, and work through the mathematics used to calculate the rib taper. Understanding the Three-Dimensional Geometry I begin with the fundamental geometry of the oud bowl and explain why its curved, three-dimensional surface presents a challenge when designing individual ribs. Using a full-scale cardboard model of the bowl geometry and my inner bowl profile template, I demonstrate how the profile can be moved from side to side around the centerline to visualize the bowl’s form. Imagine having a material that could be stretched over this three-dimensional structure. That surface would represent the bowl itself. But wood cannot simply be stretched into shape. Instead, the bowl is constructed from individual wooden ribs, each carefully shaped to contribute to the final form. Understanding the relationship between the profile, the three-dimensional surface, and the individual ribs is fundamental to developing an accurate rib design. What If the Oud Bowl Were Not Made of Wood? In my previous episode on how the oud produces sound, I explored the relationship between the instrument’s construction and its acoustic behavior. Here, I extend that discussion with a question: What if there were no wooden bowl? The oud bowl does not have to be made exclusively from wood. Composite materials, including fiberglass and carbon fiber, offer alternative approaches to constructing a curved shell. These materials have different physical and mechanical properties, opening up possibilities for investigating how material selection might influence the instrument’s behavior. Historically, instrument makers worked with the materials and technologies available to them, and wood became central to the traditional construction of the oud. Wood remains a practical and established material, but its historical importance does not mean it is the only material worth investigating. I am beginning to research the acoustic properties of different materials, including different wood species, fiberglass, and carbon fiber. The objective is to develop a better understanding of how material properties relate to the construction and acoustic performance of the oud, and to apply that knowledge to my own work. This is an investigation into possibilities, not a claim that one material is inherently superior to another. The properties of the material, the geometry of the bowl, the construction method, and the behavior of the completed instrument all deserve consideration. Calculating the Oud Bowl Rib Taper The final part of this episode focuses on the mathematics behind the rib taper. Using my inner bowl profile and a defined angular allocation for the main ribs, I work through the calculations required to determine the rib arc length at successive stations along the bowl. The calculations are based on the relationship between radius, angle, and arc length: L = Rθ Here, L represents the rib arc length, R is the bowl depth used as the radius at a given station, and θ is the angular allocation expressed in radians. For this design, the working assumption is that 11 main ribs span a total angle of 150 degrees, with two additional edge bands to be considered separately. This provides a consistent geometric basis for calculating the rib taper along the length of the bowl profile. I present the station measurements, the underlying formula, and the resulting rib arc widths in the accompanying clips so that the calculations can be followed and referenced independently. These calculations establish the geometric basis for the rib design. The next stage is to translate that information into the practical dimensions and shapes needed for construction. The Bigger Picture This episode brings together geometry, traditional instrument making, materials research, and mathematical design. My goal is to understand not only how the oud bowl is constructed, but also why its geometry works the way it does and how a more systematic approach can inform future design decisions. By combining established construction principles with engineering analysis and materials research, I hope to explore new possibilities while maintaining a clear understanding of the oud’s traditional form and acoustic function. Thanks for following along as I continue developing my own approach to oud design and construction. #Oud #OudMaking #OudConstruction #OudBowlRibs #OudRibTaper #OudBowl3DGeometry #OudRibDesign #OudRib #AcousticEngineering #CompositeMaterials #CarbonFiber #FiberGlass