'Lama V4' intermittent TBE

[userrc]

Hello,
I'm a beginner at RC heli. My 'Esky Lama V4' randomly develops TBE (heli head points in same direction and moves in circle) when given small input. I ensure both blades are staight, but still it prevails. It then goes away, without my identifying the cause. Please tell:
1. How to cure common TBE ?
2. What all things to do while adjusting blades ?
Please explain in detail, with pictures if possible. Is 'Blade balancing' required for 'Esky Lama V4' ?

Thank You.

[withnail]

How high from the ground are you when this starts?

As for balanced blades, I have found that when using some of the standard black blades these can be fairly badly matched. I switched to using the white extreme blades and found that they removed all the vibration.

Cheers

Mark

[userrc]

Thanks. Height was from 1 feet to 3-4 feet.

[withnail]

When below about 3 feet the Lama V4 will tend to wander about. The rotors produce a large downdraught which, when close to the floor, tends to bounce back up towards the model. All this unstable air is more than enough to make the helicopter move as you describe. As you get a little higher the effect should fade. It doesn't take too long to get used to correcting for this effect when low to the ground. I spent a few sessions lifting off to a height of about 6 inches (helicopter tail facing me) and practicing keeping the helicopter hovered over a 12 inch square piece of card placed on the floor. As I practiced I was able to reduce the size of the target on the floor. Now I can hover over 2 CD cases placed next to each other (well MOST of the time hehe)

Once you get used to hovering the model at different heights you will feel more comfortable moving slowly forwards/back and side to side. Once you have mastered this you can start with the helicopter facing towards you and work through the same process.

Hope that helps?

Mark

[userrc]

Thanks. But air downdraught is not the problem as sometimes, at same height, heli is perfectly stable.
I feel it might be blades.

[Boggy]

hi guy
the most common cause of tbe is fly bar problems.

1. make sure the flybar is straight.
2. make sure its free to move in the carrier and not sticking anywhere!(the biggest cause)
3. hover the heli and make sure the top blades are in track. if not ajust the link between flybar and blades(trial and error till you get the right direction to adjust)
4. make sure the ball links are free on that small arm.(nip them with pliers to free them if they are tight)


i doubt very much if ground effect is causing tbe! tbe is constant g/f is erratic!! so if its happening randomly look towards that flybar sticking!

[userrc]

Thanks Boggy !

3. hover the heli and make sure the top blades are in track. if not ajust the link between flybar and blades(trial and error till you get the right direction to adjust)

Please explain.

[jboweruk]

Okay, when you look at the top blades at eye level (you need a small piece of sticky tape a total different colour to the blades for this so you know which blade it is, stick it to one of the upper blades) you should see the end of the blade as a single entity, if you are seeing one higher than the other, then they are out of track. Obviously you will need them spinning, so keep your face away from them and hold the heli from underneath to do this. If they are out of track then look for the little bar that goes between the flybar and one of the blades, it will be attached to a ball linkage at each end. Carefully unclip this at the blade end and then gently screw it either clockwise or anticlockwise one turn, then check again to see if it's better or worse. If it's worse go 2 turns in the opposite direction, rinse and repeat until you have a single entity with your blades. At this point they are in track. Until this is done no ammount of proper trimming will make much difference, which I've learned through trial and error, as well as getting a lot of advice from on here. Let us know how you get on.

Oh, and the sticky tape? As you go on you will learn which blade moves, and the sticky tape will after a few goes of this help you to know which way to turn the flybar linkage. You will get to know which blade it's on and if you attach the tape to the same blade the flybar is attached to, you will know whether you need to bring it up or down to level off to the other blade.