Vibration issue - need advice

[cbdane]

Well, I always said that I didn't have any vibration issues but maybe I was just in denial. ;) My vertical tail fin is always completely still, my boom struts show no vibration, and no signs of foaming in my fuel; just a little ripple on the surface.

Here's the problem. I first installed a set of RCBooya canopy mount screws and just couldn't keep them in. Next, based on a suggestion here, I replaced the aluminum thumb screws with nylon ones. No more problems. Recently, though, I received a new canopy attachment system from QuickUK. No matter what I did, the lower left (from the pilot's perspective) would always loosen up. I'd tighten it a little more on each flight but always loose after landing. This morning, I found it loose after my first flight and when I went to retighten, there were no threads left in the aluminum. :shock: Not just stripped out, but the threads were removed as clean as a whistle.

So, anyone else had this problem? I must have some sort of strange vibration that only exhibits itself through the canopy screws. I never hear about this so I know that most folks don't have this experience.

Any thoughts on what to suggest?

So far:
- main blade balance: check (no balancing required)
- tail blade balance: check (no balancing required)
- paddle weigh in: check
- flybar centering: check

I'm stumped.

[OTA]

A piston engine will always contribute some high frequent vibrations not matter what you do. Thats just the physics of this. Any bolt not loctited will come loose. Every time you have re-tightened, you have slightly stressed/worn the threads.
Sounds to me that you have a perfectly healthy (and proper balanced) heli and that you probably just should go back to the original canopy mount. The original rubber mount sucks but hang on there;)

[skigolfmike]

Didn't have the canopy screws backing out issue. I did have a bunch of weird vibes today though. First I got a pretty good wobble in normal. Looked to be in the head, so I put it in idle 2 and it smoothed right out. Grips were too tight. Then I got a wobble in idle 2. Turned out the TR bellcrank was coming loose and messing with the tail. Fixed that and test flew later - random wobble/vibes gone. I loosened the grips slightly too. The blades are still pretty tight in the grips though.

[NolanManley]

It's your clutch wobbling in the bell. :Bang :banana

[skigolfmike]

Could be. I guess I'll find out soon enough.

[Rototerrier]

Had the EXACT same thing happen to me yesterday on the EXACT same screws. Mine still has some bite left, but there was a little strip of ally on the outside thread. It's chewing.

I have a couple extras left over from my original order of mounts. A budy of mine cross threaded 2 mounts on my first set...and I hadn't had them long enough to know better...so I ordered another set. Honestly..these mounts are rubbish. They look great...but are crap..too soft. I have the QuickUK mounts on my 600. Rock solid and they tighten up and bottom out. You could NEVER EVER strip them by human hand force. These RCBooyas are just so damn soft you can strip them very very easily.

I don't think you...or I, are vibing to the point that a healthy mount will give loose. I think the mounts are just to the point where they are about to stip out anyway and the normal vibes are causing them to back out.

Loose the booyas and go for quickuk mounts. That's where I am headed as soon as I eat thru my spare booyas.

Edit: I just did some research into these rcbooya mounts and it appears he has released a new version using different threads and material. I have the originals. Might be worth looking into the new versions.

[skigolfmike]

I just got my RC Booyas in the last batch sent to ReadyHeli, so maybe mine are the new ones

On my 700 loosening the main blades grips slightly and getting the play out of the TR bellcrank fixed my apparent vib problems.

[cbdane]

It's your clutch wobbling in the bell. :Bang :banana

:P

[Rototerrier]

The new V2 RCBooya canopy mounts are much better. All the original issues are now resolved. Harder material, finer threads, and a couple mm insert to help guide the threads in. No more cross threading.

Time will tell how well they hold up, but they are noticable better and easier to use now.

[Danal Estes]

RCBooya V1 and no problems so far. And My T700 shakes like a crack addict in withdrawal. I just fly it anyway... nice to know about the new ones in case I do have problems.


And, Roto, read the the original post again, he lost the threads in QuickUK mounts, not Booyas...?