Home▸Physics & Mechanics▸Spool Pulled by a Thread - 3D Physics Simulation of Torque, Rolling and the Critical Pull Angle

🧵 Spool Pulled by a Thread - 3D Physics Simulation of Torque, Rolling and the Critical Pull Angle

3D physics simulation of a spool pulled by a thread: torque about the contact point, rolling acceleration, the critical pull angle cos(theta)=r/R, static and kinetic friction, with live graphs and checks.

Physics & Mechanics3DModerate60 FPS📱 Mobile-adapted🟠 Blender⇄ 2D version

⚙ Under the hood

3D physics simulation of a spool pulled by a thread: depending on the pull angle it rolls toward or away from you, with torque about the contact point, critical angle arccos(r/R), friction limits and an energy balance.

TorqueRolling MotionFrictionRigid BodyClassical Mechanics

3D · Three.js / WebGL renderer · 60 FPS target · runs fully client-side, no install