Cold-calling that students actually trust is fair
Students notice patterns — if the same few names get called on repeatedly, or the teacher seems to 'always' pick certain people, it erodes trust in classroom participation even when it's unintentional. A visible random picker removes that perception entirely: the whole class can see the roster on the wheel and watch the spin land on a name.
For a full-roster cold-call session, turn on elimination mode so each student who's been called drops off the wheel, guaranteeing everyone gets a turn before anyone repeats. For a single random pick — like choosing a line leader or group captain — leave elimination off and spin as many times as you like.