v120d02s bobbing

[bagofsoup]

hello all,
I'm Noticing alot of bobbing up an down, kind of hard to keep altitude and i'm a total newb with CP helicopters, anyone have any ideas as to what mabe causing this, i read one post that mentioned to check the collar to ensure it wa tight "which i did, and it's tight with no play", any other ideas ?

[oxide1]

make sure that the is nothing touching the receiver.... is really sensitive to vibes, also check you servo movement.... make sure there is no notchy/jumpy spots....

[bagofsoup]

Hey thanks for the info, i checked the Rx, nothing is touching it, although it's close to the servo, but this thing is tight for space anyway, also it has double stick foam tape which is holding it in place. swash is level, blades are tracking, the coller is snug and there is no play in the main shaft, there is no server binding, or twitching.. it just seems to bob up and down in a hover. is it normal?

It just seems that when im in a stable hover, it loses altitude, then i have to increase the collective, then correct it again, to get back at the same altitude. if i hover it steady in one place it is noticable, I'm a total CP noob, been learning from the people on these forums through trial and error. i use Normal for spool up, i hover in IDLE1 throttle is 80%-100%, IDLE2 throttle 95%-100%, im not an expert but from what i was reading i think the headspead should be fine.

Any thoughts ?

[oxide1]

that definitely doesn't sound right.... once you're in a stable hover, the v120 should stay rock solid if everything is right. Have you tried using a flat throttle curve in idle up? say about 85% ? that way you are only rely on blade pitch to gain of decrease altitude, rather than both blade pitch and throttle.... also.... you said you're a bit of a noob..(i still consider myself one, and been flying for well over a year!) are you running any expo on collective and cyclic? if not, that might be your problem... even tiny movements can send these things flying... you might be moving your collective without even noticing! a bit of expo could help soften that out a bit....
all that being said... they are just ideas.
the 2 times i've had "bobbing" first time it was the collar, second time it was the front servo, the servo took a looong time to figure it out... i checked it about 3 times using movement from collective and cyclic before a finally pulled the servo apart and found a broken tooth, fixed it, problem solved!
i hope some of this helps!
also... if you haven't already, checkout finless bobs setup videos in the tech section on here! they're awesome!

[MiXiN]

Check the head dampers and reseat all the connections.

[bagofsoup]

Hey Thanks for your input, unfortunatly i thought it would be a good idea to fly after a few cocktails "bad idea" i ended up breaking the gear which drives the tail gear which is located under the main gear as well as a tail blade, i fixed the gear but still waiting on my tail blades, i will try all of your suggestions when my bird is back in action.

Thanks,

[bagofsoup]

Thanks for all the information, i just got my tail blades in and after flashing my Devo8s with Deviation i put this little bird back in the air, while i was holding the heli i noticed that there was play between the collar, which apparently when i first checked i didnt push the main gear up, so i just assumed that there was no play, so after snugging the collar down to remove the play, this bird flies like a Champ..... amazing how a little bit of play affects these helicopters..

Thanks for all of your help....

[Bollis]

Originally Posted by bagofsoup

Thanks for all the information, i just got my tail blades in and after flashing my Devo8s with Deviation i put this little bird back in the air, while i was holding the heli i noticed that there was play between the collar, which apparently when i first checked i didnt push the main gear up, so i just assumed that there was no play, so after snugging the collar down to remove the play, this bird flies like a Champ..... amazing how a little bit of play affects these helicopters..

Thanks for all of your help....

I have this error in my new heli to, when in hoover it changes hight with almost 1m up and down.

Im not so good in english, could you please describe for me what the collar is?

Best regards!

[fishcake]

it's located on the main rotor shaft below the swashplate. when you push the main spur gear up, make sure there is no gap between the metal circular object and the main plastic frame.

[Bollis]

Originally Posted by fishcake

it's located on the main rotor shaft below the swashplate. when you push the main spur gear up, make sure there is no gap between the metal circular object and the main plastic frame.

Thanks! Now its workingagain.