Total N00b Struggling with Trim...

[DJKaye]

Hey guys, I'm totally new to RC helis and to the forum but have a question...

I've just bought a Hubsan Mini Invader 4ch heli which is great fun, but I'm struggling to sort out the trim. Instead of having sliders, the transmitter has buttons making it very difficult to know where they're set to. At the moment it's taking off to the right or left and I can't find the middle ground!

It's doing my head in and I'm sure has been asked on here before, for which I apologise! Has anybody got any tips? I'm really excited to get on top of it and enjoy it!

[Boggy]

Hi DJ welcome to the forum. Does your transmiter bleep when you move the trims? usually they have a hi pitch bleep at center and a lower pitch at full adjustment left or right/up down.

[DJKaye]

Thank you!

Yeah it does bleep but I've only heard the different pitch on the throttle trim and not for the aileron trim. For the aileron trim it does bleep when you press the buttons but as I mentioned I've just not noticed the different pitched tone.

[Grumpy]

Most helis will tend to initially drift left after lifting off due to the side thrust generated by the tail rotor (assuming clockwise main rotor).You need to compensate for this as it lifts. Once you get it in a stable hover then you can start tweaking the trims.

[DJKaye]

Ok, so is it best to trim when it's low down or once it's in the air? I just don't have much room in the house so by the time it's in the air I'm hesitant to mess around with the trims!

[tomatwalden]

Most helis will tend to initially drift left after lifting off due to the side thrust generated by the tail rotor (assuming clockwise main rotor).You need to compensate for this as it lifts. Once you get it in a stable hover then you can start tweaking the trims.

This is the crux of the issue and catches many newcomers out, me included when I started. The effect is called translating tendency and is indeed a side effect of the tail rotor. Bottom line therefore is it is normal and NOT something to trim out. Rather you will quickly learn to apply a little right cyclic in a hover.

once you progress to 6 channel CP helis, trim isn't used anyway (assuming flybarless) and it's not something you really notice outside of a hover.

Just ts reset trims to zero and use the right stick a little to compensate.

THE HELICOPTER PAGE

[DJKaye]

Oh ok awesome, thank you for your help!

I've just discovered a bigger problem though. The main shaft cog has worn for some reason and isn't making great contact with the small cog (presumably for the tail rotor) which it contacts. This means it's making a load of noise, though I haven't noticed it affecting the way it flies *yet*. It's charging at the moment so I guess I'll see.

Is that a fairly terminal problem?

[tomatwalden]

Terminal ? No. Sounds like you've stripped the main gear slightly. This happens if the main rotors are stopped whilst the motor is still under power. Given that the motor is directly powering the blades (that small pinion against the big one), if something impedes the blades (eg. The ground!), something gives. Usually it's the plastic main gear that strips some teeth under the torque of the motor.

you just need to replace the main gear

2 mins on Google found this ... Main Drive Gear 1 For Hubsan Lynx And Invader RC Helicopters