Bottom propellers won't spin on my black spider xt

SOURCE: my helicopter wont fly

either stripped the main gear inside the heli or the main blades where they slide on the shaft. you should be able to buy a replacement set of blades. try that and see if it'll fly.

SOURCE: my green air hog helicopter

Hi,
There is a problem on the motor gear, check the underside where you could see a big gear that should spin when you try to lift the helicopter. Check both big gears if they rotate/spins.
Usually the problem is the small gear on the motor shaft that is not aligned to that big gear. Check on it and adjust the small gear of the motor.

Hope that copter flies high.
Thanks for asking FixYa!

SOURCE: Where can I get copy of instructons - Air SBEGO Mini IR Helicoper

have you made sure that the helicopter is charged completely?

if so when you try to take off if it spins to the left then hit the r trim on the remote and if it spins to the right then hit the l trim on the controller.

honestly all the instructions do is tell you how to put batteries in the controller.

SOURCE: My helicopter won't take off,

This issue is the "Drive Gear Unit" It is the small gear just above the motors which is attached to the very large gear. You will have seen several posts indicating that sometimes this gear shifts and does not engage the larger gear. In my case I looked and say that it was indeed trying to engage the larger gear, however the gear is stripped (the teeth are nearly gone). The sound that you are hearing is the sound of the gear slipping against the Bigger gear. I have a UJ365 which is a newer model. To my disappointment I cannot find a "Drive Gear Unit" anywhere on line. The copter will not function without it. This issue is that it takes the lift of both rotors to lift the copter into the air. There are two motors (one for each rotor) and each motor has one of these drive gear units. Each of these attach to the larger gears which turn the rotors. The rotors each turn in the opposite direction. This is what keeps the copter from continually turning in one direction. When one of the "main Gear Units" becomes damaged it seems to have three noticeable effects. (1) There is a noise that is the gear grinding against the bigger gear. (2) Because many of the teeth are stripped the drive gear engages the bigger bear only some of the time, this causes the rotor to turn slower and in-turn causes there not to be enough lift from the rotors to lift the copter. And finally (3), someone noted that copter wants to spin in one direction. Understanding the above, you can now understand that if one of the rotors is not reaching its full potential to turn, it is also not reaching its full potential to counter act the other fully functioning rotor. Thus the fully functioning rotor is forcing the copter to spin in its direction and the malfunctioning rotor is not spinning fast enough to stop the spin.

So this is the answer to your questions, hopefully on the older models there will be parts available for you to replace it. The copter cannot work until the part is replaced.

SOURCE: I cHarged the helicopter and

try to play around with the trimmer.. i had the same problem but then guessed it was the trimmer and iwas right!