This example shows two flexible aluminium shafts modeled using a lumped parameter approach. Both shafts consist of 20 segments containing inertias, damping, and stiff torsional springs. At the start of the simulation, the clutch is unlocked and the driven shaft is free. The clutch begins engaging at 0.5 seconds and begins disengaging at 1.5 seconds. The shaft data is stored in the model preload function under File->Model Properties->Callbacks.