Georges Payne

Hello all,


I tried everything I could to eliminate wobble on my Blade CP Pro, but to no avail. This has been discussed before, I know, but the existing threads did not provide an answer to my specific problem. I need help please!!!

I trued the spindle, the main shaft, and the flybar on a flat sheet of glass until they could roll down a very shallow incline, without the need to push them to begin rolling. They are really true. I then reinstalled a new hub, and reassembled the flybar paddles by measuring with a caliper gauge to make sure it was centered, the flybar weight are exactly at the same distance from the hub, the paddles have the same number of threads, and I balanced the head assembly with the flybar but without the blades, by removing the motor, and turning the frame on its side. The rotor stays in the position I put it in. The hub turns true. There is no wobble when looking at the hub cap from above. Absolutely none. I balanced the main rotor blades with a balancer I made. I then placed the blades on a pivot to verifytheir center of gravity, and it is exactly the same on both blades. The blade grips have no play on the spindle, If I remove one washer, they have maybe 1/32" of lateral play. The spindle is not too stiff in the hub, and not loose either. I tracked the blades to within half their thickness at 75% throttle, and I checked the angle of attack at half throttle. A friend of mine bought a brand new Blade CP Pro on monday, and I was there when he ran it for the first time out of the box, and mine runs as smoothly as the new one and maybe even better, except for the wobble.

I am left wondering if there could be some wear in the ball links, or maybe on the swash plate, causing some resonance and the wobble itself. My Blade CP has flown for exactly 40 batteries, and suffered a few minor crashes, but I replaced all the parts instead of trying to save money.

I have a Futaba 9C using Wingwest's settings, and I have the G90 HH gyro.

This is frustrating, I appreciate any help I can get.

Regards
Georges

orlbuzz

Georges,

You confuse me. You say that your's is as smooth as the new one, but wobbles. Just what do you mean by wobble?

A little more description, please.

orlbuzz

Georges Payne

I mean that the rotor itself spins very smoothly at any speed, with absolutely no vibration. But when it's flying, the whole helicopter "wobbles" around its rotor, maybe two or three times every second, while keeping its heading as it is doing so. The best way to describe it with my limited English, I guess, is that it acts as if it were a rubber duck spinning inside a toilet bowl as it flushes.

TAKE OFF EH!

It sounds like your talking about your gain trimmer pot perhaps,if its a tail wag your descibing,check out page 24 of your manual to see if it sounds like what your experiencing.

orlbuzz

Georges Payne,

That's a very good description and your English is perfect!

My first thought is that maybe you should try a higher head speed.

Other than that, I'm without an idea. I'll think about that one!

orlbuzz

mrasmm

The 2 or 3 times every second is what gets me. If it was something to do with the head or something, usually it's more like a vibration rather than a wobble and happens much more per second. You could see if your buddy would let you put his head on your chopper and see if it still does it. If it does that would sort of isolate the cause. The other thing it could be is something like a cracked frame, or a servo going bad, or glitching. you might also try lubing the main bearings or something.

Is there any way you can take a video of the flight to show us exactly what it is doing?

Georges Payne

Thanks for the help, guys.

I got it, I think. The Bell mixers were loose, there was a lot of slop in the whole linkage. I tightened the small screw on each Bell mixer until the flybar was just slightly restrained by the mixers. So I deduce that they act as a kind of damper for the flybar. Because they were so loose, maybe it induced some harmonic flutter in the linkages, and caused the helicopter to wobble.

Thanks again
Georges