Unknown source of shaking

[brettboz]

I had a very small crash over the weekend and it now shakes quite badly after about 60% throttle (really noticeable in idle up).

Anyway I have changed the flybar and main shaft, both were bent. I have changed the feathering shaft although it was straight (its an align trex one). I have changed the blades although the others were not damaged in the crash. I have retracked the blades and pitch is perfect +10/0/-10.

Visually I cant see anything which would cause the shaking, any ideas please?

[Stinky Igloo]

Check your tail shaft and tail hub. They bend easily.

Make sure your flybar is centered and the paddles are level with the flybar frame.

[brettboz]

Flybar is level and centered. If I take the blades off I can spool to 100% with no shake. Therefore I ruled out the tail... but could it be this.

Also just reading some of the other threads and others have the shakes and live with it, well mine flys and doesnt seem that bad flying, just annoying, should I live with it too?

[josh mcormick]

+1

Oh and you said you changed your flybar shaft, Ive had about 35 wrecks since ive owned this bird and i just bend my shaft back, with no vibrations what so ever, As long as you get it pretty strait and level with flybar cage, you will be fine, Dont replace parts that arent bad, this hobby cost to much as it is. Also im sure you balacnced your main blades, but wont hurt to double check, good luck

[Stinky Igloo]

Originally Posted by brettboz

Flybar is level and centered. If I take the blades off I can spool to 100% with no shake. Therefore I ruled out the tail... but could it be this.

Also just reading some of the other threads and others have the shakes and live with it, well mine flys and doesnt seem that bad flying, just annoying, should I live with it too?

If it shakes with your mains on, but not off, your blades are not balanced.

Also check your blade tracking.

[brettboz]

Done both, blades are tracked and balanced. I spent a lot of time on that issue today and I am pretty sure they are as good as it gets.

[brettboz]

Originally Posted by josh mcormick

+1

Oh and you said you changed your flybar shaft, Ive had about 35 wrecks since ive owned this bird and i just bend my shaft back, with no vibrations what so ever, As long as you get it pretty strait and level with flybar cage, you will be fine, Dont replace parts that arent bad, this hobby cost to much as it is. Also im sure you balacnced your main blades, but wont hurt to double check, good luck

I have changed out about 4 flybars so far, it seems to be my weak spot.

[Stinky Igloo]

Yet, when you remove the main blades the vibration disappears?

[brettboz]

Originally Posted by brettboz

Done both, blades are tracked and balanced. I spent a lot of time on that issue today and I am pretty sure they are as good as it gets.

Just realised something, I have tracked them but not balanced them. How can I balance the blades???

[Stinky Igloo]

You could buy a blade balancer, then add clear backing tap to add weight as needed.

OR

Make your own.

Both methods, clear packing tape to add weight as needed.

Also balancing blades is a two part process, you need to first make any corrections to the CG of the blades to get them equal, THEN balance with a balancer.

Note, that the e-flite 400 blades are pretty bad when it comes to balance IME. Switch out for some align 325 pro woods worlds better in terms of quality and performance.

[josh mcormick]

Originally Posted by brettboz

I have changed out about 4 flybars so far, it seems to be my weak spot.

They rod acually breaks? Iv'e had my paddles wraped around each other, many of times and just bent back and had really god luck so far, Knock on wood. Maybe they cheapend up the steel a little more. The chinese must have thought the 5 cents they had invested in the metal was to much. I even salvage most my spindles by bending back, and end up with perfect tracking, I am currently laid off so got to make do with what i got. Good luck Brettboz, I'm sure you will find it soon

[notreallyme]

watch this it may help http://video.helifreak.com/?subpath=...lancing101.wmv

[brettboz]

Blades now balanced.... problem fixed....

The brand new blades had very different centre of gravity and very different weights. What a mess no wonder it vibrated so bad. I can't believe they make them so bad.

[Redfire SVT]

Originally Posted by brettboz

Blades now balanced.... problem fixed....

The brand new blades had very different centre of gravity and very different weights. What a mess no wonder it vibrated so bad. I can't believe they make them so bad.

Preaching to the choir, try the Align Pro Woods- you will love them.

[Swashmix]

Originally Posted by Redfire SVT

Preaching to the choir, try the Align Pro Woods- you will love them.

Tried them for the first time this weekend. Very neat quieter sound. More stable on the hover. Kept a given altitude better too. Throttle input seemed more sensitive too.