Unbreakable Tube (with a string inside)

thingiverse

Experience our third iteration of an indestructible tube, boasting impressive axial pressure resistance. Although accidental radial forces may skew its elements, they won't break it. The string inside mimics "prestressed concrete" by building tension. Flip-back ability is possible with elastic strings; use strong ones for unbreakable manual strength. Noteworthy outcomes include: longer tube parts decreasing stability and repeated bending damaging edges (as illustrated by red arrows in images). The string's tension diminishes post-bending due to friction loss from angled sections. To enhance durability, consider designing parts with constricted openings on both sides, rounded shapes, and a novel tightening mechanism. Update V3 offers improved elements and OpenSCAD optimization. Assemble your print by attaching a strong string; knot the open end. Rotate the upper part clockwise to increase tension, causing internal strings to twist. Once sufficient tension is achieved, attempt bending for a test of resilience.