TREX 500 Trim Issues

[helicopterjeff]

Is it normal for the trim to need adjusting through out the flight? I know rotor speed affects it but this heli seems to need a lot of minor trims during the flight.

Thoughts on this? I am running a high head speed after finding out that lower head speeds cause the mechanics to bobble about the rotor.

Thanks!

[T/CHunter2009]

I don't use any trim at all from start to finish. What are you trimming out during flight ?? Lets start by explaining what you need to trim out durring flight and why, I'll see if I can help .

[helicopterjeff]

I don't do any 3D with this because the servos are too slow so most of the flight is figure 8s and the like.

When I come in from a flight into a hover nose in or tail in it's always nose heavy and drifts to the right. After trimming it up its fine for a while but after more rounds it'll be tail heavy and drifts to the left.

I've noticed that it changes also with rotor speed which i thought kid of odd as my trex 450 and sceadu evo don't have this problem.

[mikesurfs]

I've found that wind, ground effect, etc. have alot of impact on still and stable hover. I used to trim alot, but once I got my bird reasonably stable, I just moved on. My heli is fairly still and constant when a few feet up and tail in, so that's what I consider my happy spot.

Mike

[lankey]

Never used trim on my birds. Firstly double check your COG is correct and swash level through the pitch range. Any drift tendancys after that are down to physics and aerodynamics!

[T/CHunter2009]

I would double check the head and make sure it is level all the threw . High mid and low stick. Something must be out of whack. Also set you pack on the deck and check for C.G . If your 5 feet or higher up you shouldn't be having any need for trim. Lower than that ,blade wash may be affecting your flight. Check and make sure your Main rotor head O ring Bushings are not worn out . I use the black ones . Good solid feel , hands off hover with no problem. I can flip into idle up add some positive pitch and let go of the sticks as she flys away. well enough to swap a nap out of my eye LOL

[helicopterjeff]

I've found from other forums here that the servos I'm using are about the lowest end needed for this heli. I am sure they have something to do with it.

I'm going to rebalance everything again. I've not checked the head dampers so that'll get done too.

Overall it's a good bird and very solid. It's just very different from all the other electrics and gassers that I've flown in the past.

I'll post what I find out after going over it again.

Thanks guys!

[Matt Nasca]

Originally Posted by lankey

Never used trim on my birds. Firstly double check your COG is correct and swash level through the pitch range. Any drift tendancys after that are down to physics and aerodynamics!

+1

[jamese]

What servos are you using?

[helicopterjeff]

I'm using HS 58MGs. I know they're not up to the task for this heli. I expect that the trim issues will be gone after I replace them.