Servo Inertia Match

Load inertia reflects to the motor as J / N² — which is the entire reason gearboxes make big loads drivable. An inertia ratio under about 5:1 tunes easily; above 10:1 the loop gets sluggish and prone to ringing unless the coupling is very stiff.

The optimal ratio √(Jload/Jmotor) maximises acceleration but often gives an impractical speed — pick the nearest stock ratio and re-check. Torque here excludes gravity and process load.