Differentiating the loop equations yields angular velocities using the known input angular velocity.
Breaking into (x) and (y) components for a given crank angle (\theta_2): 4 bar link calculator
Second derivatives provide angular accelerations, essential for force and inertia calculations. 4 bar link calculator
Given link lengths and crank angle, output the angles of the coupler and follower, plus the coupler point position. 4 bar link calculator
[ \mathbf{r}_1 + \mathbf{r}_2 = \mathbf{r}_3 + \mathbf{r}_4 ]
[ r_2 \cos\theta_2 + r_3 \cos\theta_3 = r_1 + r_4 \cos\theta_4 ] [ r_2 \sin\theta_2 + r_3 \sin\theta_3 = r_4 \sin\theta_4 ]