This 2D side-view simulator reimplements the classic counterweighted traction elevator as a canvas cross-section: a cabin and a counterweight hang from opposite ends of the same cable over a sheave, sliding on their own guide rails inside the shaft. Load the cabin, size the counterweight, pick a target travel speed and call the cabin between five floors — the animation drives a real trapezoidal speed profile while the readouts compute the actual net static force from the weight imbalance, the instantaneous acceleration, and the motor power (including negative, regenerative power when the heavier side is coasting downhill with gravity's help).