What is the typical brake clearance for gearless machines?

• A. 5-6 thousandths of an inch
• B. 1-2 thousandths of an inch
• C. 3-4 thousandths of an inch
• D. 7-8 thousandths of an inch

Answer: (C)

Brake clearance is the small gap between the brake lining and the braking surface when the brake is released. In gearless machines, keeping this gap tight but consistent is crucial so the brake can engage quickly without dragging during release, while avoiding wear or binding.

The typical clearance is about three to four thousandths of an inch (0.003–0.004 in). This range provides near-instant braking response when power is applied, with minimal residual contact when released. If the gap were larger, the brake would take longer to apply and could lose some braking torque at the moment of engagement. If the gap were smaller, there’d be a risk of slight contact during release, leading to wear, glazing, or binding over time.