These A40 series motors are designed for 3D-Aerobatic models up to 6 pounds and Scale models up to 8.8 pounds using 3 to 6 series LiPoly batteries.
The A40-8L 8-Pole Heli is specially developed for 500/550mm Class heli’s using 4-5 cell Lipoly (3800-5000mAh). These very high RPM Outrunner type motors have been optimized for Helicopter use. Featuring: 8-Pole High-Temp Neo Magnets, low resistance windings, special Heli-Stator, Fan cooling, High RPM Bearings, and precision ground and hardened output shaft.