Die Press: Slider-Crank + Flywheel
The machine from Chapter 4.4 and Woodworth's die books, running live. Watch the flywheel slow at each punch. Move the sliders. Open the assembly with EXPLODE.
The kinetics on screen
The punch force is the sheared area multiplied by the shear strength. The flywheel stores the energy and slows when the punch takes it:
$$ F = \pi\,d\,t\,\tau, \qquad W \approx \tfrac{1}{2}F\,t, \qquad \tfrac{1}{2}I\left(\omega_1^2 - \omega_2^2\right) = W $$
The simulation integrates $I\,\dot{\omega} = T_m - F\,|dy/d\theta|$ each frame, with a small governor motor $T_m$. Make the stock thicker and the dip grows. Slow the press and the dip grows too, because the stored energy falls with $\omega^2$. Chapter 4.4 derives each equation. Woodworth's Punches, Dies and Tools (1907) shows the real machines.