### Disk and Shoe Brake Equations and Calculators

 Disc Brake Calculator A sectional view of a generic disc brake with calipers is illustrated right. Calculate Brake Torque Capacity Input Clamping force,  F = lbf Coefficient of friction,  μ = - Caliper mean radius,  Rd = in Number of calipers,  N = - Calculation Braking torque,  T = 2*μ*F*N*Rm in-lbf Shoe Brake Calculator Stopping capacity is proportional to the normal force of brake shoe against the drum and coefficient of friction. Calculate Brake Torque Capacity Input Coefficient of friction,  f = Brake shoe face width,  w = in Drum internal radius,  Rd = in Shoe mean radius,  Rs = in Shoe heel angle,  A1 = degrees Shoe angle,  A2 = degrees Shoe mean angle,  Am = degrees Right shoe maximum shoe pressure,  Pmr = lbf/in^2 Left shoe maximum shoe pressure,  Pml = 150 lbf/in^2 C = in Calculation X = (Rd - Rd*Cos(A2)) - (Rs/2)*Sin^2(A2)) X = Right shoe friction moment,  Mr = ((f*Pm*w*Rd)/(Sin(Am))*(X) Mr = in-lbf Y = (0.5*A2) - (0.25*Sin(2*A2)) Y = Right normal forces moment,  Mn = ((Pm*w*Rd*Rs)/(Sin(Am))*(Y) Mn = in-lbf Brake cylinder force,  P = (Mn - Mr) / C Answer:  P = lbf Z = ((Cos(A1)-Cos(A2)) / Sin(Am) Z = Right shoe brake torque capacity,  Tr = f*Pm*w*Rd^2*(Z) Tr = in-lbf