ROAR would like to announce the final rules for 25.5 brushless motors, effective immediately
October 15, 2015
ROAR Spec 25.5 motor: Only three slot "Y" wound stators are permitted. No delta wound or slot less stators are allowed. Only circular (round) pure copper magnet wire permitted. The three slotted stator must be wound with 25.5 turns of two strands of wire with a maximum diameter of .643mm per slot. The minimum resistance between any 2 phases of the motor (AB, AC, BC), when measured at 25C with an Instek GOM 802 milliohm meter, will be no less than 101 milliohms. The stator stack length must be a minimum of 19.7mm and a maximum of 21.0mm. Only 12.3 mm diameter rotors will be permitted in 25.5 Spec motors and the diameter must measure 12.30 +/-.05 mm. The rotor magnet length must be between a minimum of 25.0mm and a maximum of 26.0mm, not including any balancing material."
