450 Getting frustrated now.. Need help :/

[coolgabsi]

Ok,

So As you all have probably heard, I rebuilt my 450 pro with a DFC head, and I have been trying to find a vibration issue on my heli.

So, now that its all back together again, and maidened, I am still seeing some vibration somewhere, its not as bad as before, but still there. Now mind it, I tore this thing apart, and changed every dang bearing I saw, except the one way. The gears are new on TT front and back. Blades are new and balanced (donest matter, spool without them gives vibes too) .. Tail fin I can see it vibrating, and FBL gyro is not liking it at all!


One main bearing block is new, both main bearings are new. Motor mount is new, TT bearings are new, and TT bears are new. Tail case bearings are new, oiled. The bird is smooth like silk when i push the blades with my hand.. it rotates a couple of times just on my desk fan blowing some air.. So I know i dont have a bind anywhere. BUt still a vibration ..

Just cant figure it out.

Yesterday FBL gyro saved my butt.. Lost my tail push rod some how, and the tail went crazy when inverted, FBL gyro kept it level doing fast pyros for 30 seconds until i slowly got it over grass and inverted autoed it best I could.. Loss: the tail push rod.... thats it. nothing else hurt.. but, I am thinking that wa just my fault and unrelated to the vibe..

I need IDEAS.. I need help.. this 450 is getting on my nerves.

Gaba

 

[breeze400]

If all the bearings and things are good, it's got to be a slightly bent shaft or some thing?

 

[heli-maniac]

are you running a carbon tail boom if so it could have a crack making it do that

 

[Lee]

You remember the issue i had Gaba? I changed everything. It was the tail boom in the end cause a resonant frequency. Try a different boom especially if its carbon.

 

[Tony]

double check main shaft and feathering shaft. If those are good, check motor shaft and tail gear shaft. Then check the tail blade shaft. If it has a shaft, check it. Also weigh the blades to make sure they are the same weight.

 

[Lee]

One other thing i remembered. Where is the TT bearing set at in the boom? If its centred, this can cause vibes. Move it slightly off centre towards the frame. I actually put two in my 500.

 

[coolgabsi]

that is interesting lee... I should not have the bearing centered? interesting.. I also realized that I was making the TT very very tight on both ends.. I have to leave a bit of play on both ends to reduce vibrations. I have a new TT bearing in it now, I will put in new TT, and a new push rod.. the pitch control arm flew away after the ball link came off the tail, blades hit it, and it went bye bye.. so that'll be new.. also I'll see if I can put a new slider. that will basically cover everything on the tail lol.. Trip to LHS today.. lets c...

Update on my P-51 (out of place but still.. ) : the engine is rebuilt and smooth. I am gonna start working on it, and finally get that thing just enough that it can get in the air. test it out, and then start building little things like the scoop and other cosmetics.. gonna start with the drooping landing gear tonite hopefully!

Gaba

- - - Updated - - -

that is interesting lee... I should not have the bearing centered? interesting.. I also realized that I was making the TT very very tight on both ends.. I have to leave a bit of play on both ends to reduce vibrations. I have a new TT bearing in it now, I will put in new TT, and a new push rod.. the pitch control arm flew away after the ball link came off the tail, blades hit it, and it went bye bye.. so that'll be new.. also I'll see if I can put a new slider. that will basically cover everything on the tail lol.. Trip to LHS today.. lets c...

Update on my P-51 (out of place but still.. ) : the engine is rebuilt and smooth. I am gonna start working on it, and finally get that thing just enough that it can get in the air. test it out, and then start building little things like the scoop and other cosmetics.. gonna start with the drooping landing gear tonite hopefully!

Gaba

 

[Tony]

Get the Pro v2 TT, it's carbon and not aluminum. Won't bend and doesn't vibrate as bad. Put a dab of CA to hold the bearing on the shaft. This is what is called for on the align kits, I did it and it worked quite well.