w7spy

Hello... I've about two hours time on a new cmx s300. It's worked perfectly until now. Probably my doing, but I can't see where. I broke the rotor-head and while replacing it I changed the lower rotor blades to white. Everything went well, I thought, but it wouldn't lift off and had a severe right yaw. I found the lower rotor stopped very quickly when throttled off. The lower rotor doesn't spin as freely and smoothly as it did before my tinkering around. Turning the lower rotor slowly, I can feel a very slight resistance and it's not as smooth turning as before. It does spin up under throttle, but not as free and fast as normal. Something is amiss with the lower rotor system, but I can't see what it is.

In changing the inner shaft, I loosened the upper-rotor gear wheel to remove the shaft and held it steady while inserting the new. The clearance between the gear wheels looks and feels the same as original. The only unusual thing I did was check the screws that I previously couldn't reach for tightness. The assembly looks just as it did before taking it apart, but something has certainly changed.

Although these little helicopters are totally tough, they appear to be very sensitive to tuning and adjustment. I hope someone has had some experience in this area and can point me toward finding a solution and getting back to my flight lessons. Thanks