450 very high frquency vibration (you don't see it but its there)

[DavidDutch]

Any body has an idea

What is happening, I wil try to explain. Already at spool up there is a very high frequency vibration which already is shifting the heli of my landing platform (during complete spool up, so not the vibes at certain HS).
Whith flying I don't see it (and actually flies good) ,but I know its there (also my logs show a lot of extreme vibration levels)

What I have done sofar :

replaced all bearings, replaced complete main block incl bearings
replaced the complete tail section
blade tracking (tail and main blades)
replaced MG and tail gears
replaced mainshaft
I have completely no play in tail or head

all runs very smooth tail and main drive train. But I am actually little out of options at the moment

it is a 450pro with fbl head (no DFC)

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If it is not clear I can make a short video.

 

[Tony]

Have you balanced your blades? Are you sure your feathering shaft & main shaft are perfectly straight by rolling it on a piece of glass? Are you running a carbon fiber tail boom (Lee had this issue)?

 

[trainrider06]

Maybe there is metal on metal somewhere rubbing where it shouldn't be....metal would make that high pitch, and vibration....what about the motor? It could be getting ready to go out....

 

[DavidDutch]

Have you balanced your blades? Are you sure your feathering shaft & main shaft are perfectly straight by rolling it on a piece of glass? Are you running a carbon fiber tail boom (Lee had this issue)?

yes blades are balanced, feathering shaft is straight, just running alu tailboom. But maybe I found it. I checked again this afternoon the mainshaft, and have doubts if it is perfectly straight, so i exchanged it again from one of my other 450 which I am sure is straight. And did a very fast hoover ( because rain was coming down) and it looked like the vibe is gone, only had one raised error and the rest was green and healthy in the logs and also the heli didn't move from the spot, while before this all was very high and extrem level and the heli shifted away

So how much chance does somebody have that both new align mainshafts are not completely straight...........they were both in the same package and bought new.....pffffff tomorrow visiting my lhs to exchange them. I never check new align shafts and never had this before.

glad that the problem (hopefully) is found

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will give final answer if solved if it is little dry over here

 

[trainrider06]

Well if that's it I guess a lesson learned for all to check new pets if an issue comes about when replacing em

 

[murankar]

I had a bend in my main shaft that was just below the head block. Strange thing is that it did a slight camel hump. My father in law took it to work so he could do a run out test. I knew it was bent but could not find it. It took a machinist to find the bend. After June I loose this benefit.

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[trainrider06]

I had a bend in my main shaft that was just below the head block. Strange thing is that it did a slight camel hump. My father in law took it to work so he could do a run out test. I knew it was bent but could not find it. It took a machinist to find the bend. After June I loose this benefit.

Sent from my LG-E980 using Forum Runner

Uh Oh father in law retiring? Or is that when the divorce is final?

 

[murankar]

Retirement, thank god. The latter would be sucking and I would never be flying.

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[DavidDutch]

just short update. Problem solved just took the heli for a fly and vibes are gone (raised is the hoghest I get).

So indeed next times (if there are any) when replacing the mainshaft with brand new ones I will also check these to see if they are ok. I hardly replace them but thought would be a good idea since the old MS was from my Original FB head.

 

[trainrider06]

Retirement, thank god. The latter would be sucking and I would never be flying.

Sent from my LG-E980 using Forum Runner

Yeah I've been through sadly 2 of those....takes years to recover financially from.....

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just short update. Problem solved just took the heli for a fly and vibes are gone (raised is the hoghest I get).

So indeed next times (if there are any) when replacing the mainshaft with brand new ones I will also check these to see if they are ok. I hardly replace them but thought would be a good idea since the old MS was from my Original FB head.

Good deal! Those sorta things can sure make for a head banger to figure out.....

 

[murankar]

Main shafts need to be check periodically. Even on hard landings you can bend it and not know it. My last main shaft was the second main shaft I had to replace. The first was due to a crash, the second was just old and beat up. I had some hard landings from attempting low autos on a 450 size. Feathering shafts also need checked regularly if your not crashing a lot.

Sent from my LG-E980 using Forum Runner

 

[DavidDutch]

yep I know but never expected 2 brand new out of the packaging mainshafts from align would be bend already. (then better could have bougth the HK ones, then it might be) but they are already switched by the LSH for straight ones

 

[Tony]

Could have been the handling of the package when it was shipped to the hobby store. If something slammed down on them, that would be all it would take to bend them. Quite rare. I have never gotten a bent one from Align.

 

[DavidDutch]

I also have never experienced it (but I am not changing them often , also the align shaft supplied with the VCTRC500 was perfect