Gyro failure?

[BruceHuang]

Hello there,

I use a gp750 on my trex 450, and today I went out for a bit of fun. Just hovering and strange things happened, the tail suddenly went to right, I corrected it n thought it was nothing to worry about. However, I brought the heli down to low attitude, it happened 3 times more. After I deciding take it down, it happened again and the heli was about 15cm above the ground, had no time to correct and the heli flipped over. Has anyone had this problem before? Or the gyro might be broken, the gyro I ve used for approx 40 flight.

Thanks

[Roundwords]

I had the same thing happen a couple of days ago with my 450 Sport. Flight number 25, I took off and about 18" off the ground the nose went hard right and she rolled into the ground.

I'm not sure what the problem was/is but I found no mechanical problems so I trying to eliminate any electrical/radio issues. I'm looking at these possibilities:

1. Radio interference. I had just the night before tucked the motor wires inside the fuselage and I might have gotten them to close to the receiver.

2. Possible static problem with belt drive system. I plan on applying some type of anti static compound to the belt such as silicone or graphite.

3. Faulty GP750 gyro. At this point all I can think to do is put training gear back on and do low altitude hover and see if the tail kicks out and hope the training gear will save her from a crash.

Like the OP, I'm open to any suggestions on what might be the problem.

[1BADAIR]

static
gyro tape loose/worn
faulty servo

[Wolfpackin]

Tail going right, CCW, can also be an indication of something in the tail system slipping.

The usual culprits are the tail drive gear/pulley assembly, tail rotor shaft pulley and the tail rotor shaft at the hub set screw.

[cooper998]

sounds like what is happening to mine, was out practicing my hovering and got too close to the flower bed, I set her down easy but the tail rotor was hitting the flower bed border, been having trouble ever since. When I try to hover the tail swings to the right and I cant control it no matter what I do, rudder input has no effect. Will probably take it apart later to check the shafts and pulleys, hopefully its not the gyro gone bad.

Tony

[Truker]

Can't remeber were I read it, but something about resetting the gyro by switching between hh @ rate a few times 3 or 4 can't remember, worth a try.
Not that I have one of those but you never know.

[weng]

I had a problem on my sport with a 750 gyro. While hovering the tail would kick out randomly to the left or right 90 degrees.
I tried repositioning the wires, remounting the gyro, replacing the tail servo, RX and ESC and making sure everything was OK mechanically. I was hoping it was not the most expensive single part on the heli.
I finally replaced the 750 with a 780 and the problem has gone away, probably 30 flights now with the 780.
I sent the 750 back to Align but was told it was out of warranty but they did replace it with a new 780 for half the current list price.
I have a 750 on my 250 with over 100 flights and have had no problem with it.

JW