That Sinking feeling

[sprinter]

After many hours and many £s I have just taken the balls off my 450 Pro. I can take off and land (near to where I want to!) and can manage a reasonable hover. However the heli is continually "bobbing?", ie losing height then picking up just when I have it at my safe height (3'-4'). Is it my lack of skill? is there something I've missed?
Thanks in advance for any suggestions.

[brin]

hi and welcome to the forum sprinter.was it doing it before you took of the training gear,with the t/g on you would use a bit more throttle increasing the head spead and making it more stable without it the heli will be a bit more nimble so it maybe just changing the throttle and or the pitch curve might help.

[Al M]

I had a similar situation with my Raptor. It turned out that my Futaba Tx still had the ratchet on the throttle. The ideal setting for the heli was between 2 clicks. So I was either too high on the throttle or too low. Was solved by removing the ratchet so the throttle could be set more accurately. It works fine now, I can generally get a good stable setting without having to lift and lower the throttle continuously.

[J-S-Q]

A certain amount of 'bobbing' is perfectly normal due to the helicopter responding to changes in the wind so that's probably all its is and you will eventually get used to it and automatically correct it.

[antquinn]

hey !

I have been flying now for nearlly 3 week 2 of which without balls! lol

my trex 450 bobs too its the wind, wait till you get it with no wind or indoors will just sit there .

good luck

I just crashed mine was a silly mistake though, tried to run before i could walk so to speak.

ant

[GravityKills]

most likely it's the natural behaviour of the heli.
But check, whether the mainshaft collar is tight. Try to push / pull the mainshaft against the heli body. If it can move (a fraction of a millimeter is OK), this may cause bobbing.

PS most likely it's simply ground effect, an air cushion under the heli when below one rotor diameter, give or take some.

[trident3]

I've found that hovering at about 8 to 10 feet is much easier and safer than at 3 to 4 feet - if I get dumb thumbs I have an extra half-second to recover, and so far that's been enough to keep my Trex 450 sport in the air. Plus it's out of ground effect which means it's much steadier.

Sometimes I'll try and hover at three feet just for practice, and it's quite a bit harder than hovering at 8 feet.

In absolutely calm weather my heli will happily sit 8 feet up with almost no movement of the collective/throttle to hold altitude and just minor cyclic input to hold position. But in any kind of breeze, it needs constant adjustment - and in a gusty breeze, it gets quite exciting :-)

T3

[sprinter]

Thanks to all. Brin -- not as noticeable with gear on. I will play with the thottle/pitch curves as they are currently set up for newby, also quite a bit of expo on.
Al M -- no ratchet, my Spektrum came ready to go.
JSQ / Ant -- wind/draught from someone with a 500 does make it playful!
GravityKills -- Checked movement, seems ok. I put two shims in when building it and that is apparently the foolproof setting.
Trident 3 -- thanks for the reassurance, I tend to panic when it gets above eye level but agreed it gives more thinking time. I think I've just about grown out of the panic shutdown mode.

[millerman]

higher head speed on the 450 pro stops the bobbing but it is affected buy wind i find i run mine at 82% flat line on idle 1 and 90% on idle 2 and this makes its very stable even only a coule of foot off the ground