Help with 450

[Mike Sanders]

My T rex 450 has a bit of a tail problem. When I turn it momentarily, the tail bounces back, nearly to where it started. I have to keep the rudder on for a bit longer to make it turn. Does anyone know how to cure this?

It is a 450 pro with G Pro flybarless unit (don't laugh). I have, of course, checked that the tail slider is free.

Thanks for any help.

[Grumpy]

I had something similar to that on the old Align 3GX. The fix was to reduce I gain ('rudder locking gain' I think it was called on the 3GX)

[trillian]

I have not worked with the G pro (I did fly someone's 550 with one once, that flew quite well, although a bit robotic feeling). My thought would be to check the rotation rate setting, as it may be too low and is requiring more rudder movement than you'd like. Or see if there is a massive amount of expo on the rudder.

[p4ddy]

Flybar and 401, job done.

[trillian]

Flybar and 401, job done.

And if you have a really fast servo, it's amazing how much hold you can get with the 401. I always had them on my Trex 450s and I had cheap servos but it all worked quite well. Then I got an MKS DS95 and I could not believe how well it worked with the 401, I had huge headroom of gain, up to crazy aggressive with no wag.

[Mike Sanders]

Thanks. I have recently increased the expo from 10 to 15 % but I can't see that that should be a problem?

[Mike Sanders]

I still have a couple of Align 780 tail gyros, not in use.

[trillian]

15% should definitely not be a problem. I generally have around 18-20% on the rudder stick. Things to check would be that the rudder stick travel end points are not set too low and what the piro rate is in the G pro.

Thanks. I have recently increased the expo from 10 to 15 % but I can't see that that should be a problem?