Flexible couplings solve problems due to alignment and centring of shafts. Moreover, flexible couplings facilitate assembly by providing a tolerance of 2º when aligning and centring the shaft over the gearbox fixing plate. (FC = power hp x 100 rpm on shaft). Coupling selection: 1. Check dimensión: 1.1 DB coupling must be = to DB gearbox 1.2 F2 coupling must be = to F2 gearbox 2. Check admissible power: 2.1 Power coupling > Power Engine 2.2 Power Coupling = ((N/R)/100) x FC 2.3 N= engine rpm 2.4 R = gearbox ratio 2.5 FC = check value on the coupling table Example: MINI-55 with TM-345 2:1 1. Check dimensión: 1.1 DB coupling must be = to DB gearbox = 108mm 1.2 F2 coupling must be = to F2 gearbox =11,5mm --> 2 options: 40040100 or 40045100 --> 40040100 FC=13 --> 40045100 FC=20 2. Check admissible power 2.1 Power coupling > Power Engine 52hp 2.2 Power Coupling = ((N/R)/100) x FC 2.3 N= 3000 2.4 R = 2 2.5 FC = 13 or 20 --> ((3000/2)/100x13 = 195 > 52 hp --> OK.