Can not keep constant height when hovering

[sigpe57]

My 450se can not hold the same height when hovering. I don't touch the throttle stick. Hovering at 4ft, the 450se just go down about 1 1/2 ft , goes back to 4ft and goes down to 1 1/2 ft in the rhythm form.. It just has a rhythm of going up and down by itself. What setting might have affect this behavior?

Thanks,

Sigpe57

[Rick Rotorhead]

Unless its a rapid shooting up or down I'd say its pretty normal.
The Trex won't hold a rock steady, unwavering hover by itself, it will rise and fall by a foot or so every few seconds. Some setups are more stable than other, its true, and any breeze will make her climb and sink on her own. How worn is your head? Do your servos have a good centreing and little dead band, try holding the grips between thumb and forefinger and give them a light twisting - a firm,new, set-up should have little free play. Sloppy head dampeners may affect her hover stability too. Cyclic stability can be increased by using the flybar weights, or adding more flybar weight - but that shouldn't affect the up and down aspect of the hover. They also tend to keep more on one level when flying close to the ground (in ground effect), than hovering at chest hieght. So, is this early days for you flying at 4 feet up - if so you may not have seen this behavoir before.
Like I said unless its quick movements up and down, its probably normal behavoir.

[sigpe57]

I was flying 1 1/2 ft above the ground. Now I am moving to chest height. I just started to notice this behavior. I also remember my Kyosho Caliber30 also have the same behavior. Especially when I makes a turn, the up & down movement really makes the turn more difficult. Does a governor help?

[DominicD]

You flying in idle up ? But some movement is pretty normal. If your near the ground its ground effect and if your up high its the wind. The only real solution to the problem is a larger heli or perfect weather

[gravydrive]

Do you have a ratchet throttle or is it smooth? It might be worth it to take some 320-600 grit sandpaper, open up your Tx and sand down the throttle tensioner really smooth, then spread some white lithium grease on it. Things should feel a ton more smooth and it'll be much easier to make minute pitch/throttle changes without drifting too much.

[NightBlade]

I recently had helped a felow rotor head with this problem. His retaining collar was just 1mm too loose and this was causing fluxuations in pitch. Also from expierence this can be from a bent spindle shaft that connects the 2 blade grips. Make sure everything is tight and that there is minimal to no slop in the head. This will get it as steady as possible.