3d printed vertebra model

A single hollow spinal vertebrae segment for 3D printing. Hollow cylindrical core with inner diameter of 14mm. One end has an external (male) threaded boss, opposite end has an internal (female) threaded socket, coarse thread pitch M30, so segments screw together in a chain. The outer surface is anatomically styled as a human lumbar vertebrae with transverse processes (side wings), a spinous process (rear fin/ridge), and organic bone-like surface texture. Overall outer diameter approximately 50-60mm. Segment is 4 inches (100mm) tall. Designed to repeat in a chain of 10 identical segments. Symmetric left-to-right. 3D printable, no overhangs greater than 45 degrees on the core tube. Hard surface, manufacturable.