New to RC helicopters - need help

[echobot]

I just built a caliper 30 and was wondering why the heli wants to pull to the left when i try to hover?

I did re-check the swash plate to make sure it was level per instructions, but I still have a problem with the heli wanting to roll to the left when I rev up.

Since I am new to heli's, please tell me everything that I should check.

Thanks,
Ed C

[darren_uk]

"I...was wondering why the heli wants to pull to the left when i try to hover?"


You might be seeing a normal phenomenon of helicopters: they always hang one skid low.

This means that taking off and landing, they'll always lift one skid first (and land one skid first) making it look like the helicopter wants to rotate around that skid at lift.

The reason is this:

The engine driving the main rotor blades is causing an opposite twisting effect (torque reaction) in the body of the helicopter. The blades twist one way (e.g., clockwise as viewed from the top) hence the body will want to react and twist the opposite way (e.g., anti-clockwise as viewed from the top - the nose will want to go to the left).

Hence the tail rotor is sometimes called the anti-torque device. It's purpose is to blow against the this reaction and keep the body from spinning around in the opposite direction to the blades.

So in my example (clockwise spinning main rotor), the nose will want to twist left, so the tail rotor has to blow to the right to push the tail to the left (twisting the body in a clockwise direction) to keep the nose still (if the forces are balanced).

The tail's blowing to the right.

Which means the helicopter is being blown to the left by the tail rotor.

so to hover over one place, you'd have to lean in to this (lean to the right a couple of degrees).

Hence the helicopter is hanging one skid low.

Sometimes you'll see pilots who aren't used to this: They'll lift off into a hover lifting both skids at once, and the helicopter will drift to one side a few feet unti they correct it by adding in opposite cyclic.

But a correct lift is to lift one skid first.

And that goes for full sized helicopter too. One skid will always be the last to leave the ground and the first to touch the ground, and will always hang one skid low in a hover over a single point.

(also some designs, like the Robinson R22, have built a couple of degrees off the vertical into their main rotor mast to reduce this effect, so the helicopter's body will hover more horizontally)

[echobot]

Darren,

Thanks for your reply to my question about the heli drifting left, however, I think my problem is bigger than natural effects of a heli.

Maybe I didn't explain the problem properly. I am VERY NEW to heli's, so I don't know if I have everything setup proper. I am able to lift of the ground but the heli wants to drift left no matter how much right alieron I give it. If I look at the main rotor blades I can see them pitch to the right but the heli still wants to drift left. I have gone over the swash plate setup both on the heli and the radio and I can't seem to find anything wrong... but it could be since I am new to this.

Any ideas?

Thanks,
Ed

[Daz(DJLFlapper)]

Can you send a photo of the rotor head so that I can have a good look. If you can just post it on here. This sounds as if there is a problem with the flybar setup. almost as if its not working at all, of course I could be misunderstanding what it is your teying to explain.
Lets hope that a photo can show something.
Please can you confirm that the heli wants to topple almost and not turn.
have you had the heli checked by a competant pilot?
what radio are you useing?
Is this set up correctly?
There is definately something not write.

[Daz(DJLFlapper)]

Hi can you confirm that your radio is set for a 120% swash plate setting?
I notice in the picture that you have got the swash plate set for 120% I do not know the capability of the radio so can not advise you on this.
If this seems to be ok perhaps you could just try the swash plate at 90% and see if this makes any diferance.
The rest of your rotor head looks fine to me.
This is one of those times when I wish I could travel to help.
To answer your question about the gyro causeing drift. If the gyro is setup properly then it is there to help stablise the tail and prevent this turning. I can't see how it would cause the heli to want to topple.
The only advice that I can give of any use is to go to your local club or shop and have them check the model and the radio for you. This may cost a few dollars but it will help to get the Heli right for you to use. It will prevent you from needing to replace the heli if something is wrong.
Best regards,
Daz

Please let us know how things go.