🧶 Spinning Wheel: Flyer Ratio, Twist per Centimetre and Treadle Linkage (2D side view)

Side view of a treadle spinning wheel with a flyer and bobbin. Set the treadle speed, the yarn draft, the bobbin brake and the whorl size, and watch the drive band, the crank and pedal linkage and the yarn twist. Drive ratio, flyer and bobbin speed, twist per centimetre and the twist angle are computed. Uses the same kinematic model file as the 3D page, with four in-page numerical checks.