Mini Titan E325 vibrations

[TiFische]

Guys, I have just rebuilt my mini Titan after a crash and now the heli vibrates violently on spoolup before taking off. Seems that the vibration is "left to right" but it flies fine. Been trying to troubleshoot but can't seem to put my finger on it. Any ideas what I should check?

Many thanks

[speeder]

are you using the plastic main hub?
the hole that the main shaft goes into on the plastic hub will become oval after crash causing the heli to vibrate.

[feudallordcult]

are you using the plastic main hub?
the hole that the main shaft goes into on the plastic hub will become oval after crash causing the heli to vibrate.

+1. also check main & spindle shaft. whilst the material grade of the shafts are pretty strong but upon a crash, it may "upz teh lorry". if yr titan is the plastic edition, check all arms & linkages again. sometimes eyeballing alone may not be sufficient to spot defective parts. check the bearings too. What i'd normally do after a crash would be to dis-assemble the bird & build it up again. troublesome but worth it.

[TiFische]

E325 Vibrations

Speeder, yes I am using a plastic one. Never thought of that, will have to check it. Thanks.

[TiFische]

I tested the main shaft and it "rolls" ok ... will check again. Looks like its going to be a full rebuild if the simple main & spindle shaft is not sorted.

Thanks guys

+1. also check main & spindle shaft. whilst the material grade of the shafts are pretty strong but upon a crash, it may "upz teh lorry". if yr titan is the plastic edition, check all arms & linkages again. sometimes eyeballing alone may not be sufficient to spot defective parts. check the bearings too. What i'd normally do after a crash would be to dis-assemble the bird & build it up again. troublesome but worth it.

[feudallordcult]

u may wish to look at the one way bearing but I dun usually bother to check unless I hv crashed it over 5X

[misato]

Violent wobbling / vibrations on spool up aka what i called as chicken dance can be caused by a lot of factors. Usually in a crash, the main shaft and the feather shaft are one of those things that usually breaks(bents/warp) from the impact.

The more accurate DIY checking of these 2 shaft is to roll them on a flat glass surface and listen to the sound produced, it helps if you have a new shaft to compare against. If it does not sound consistent, its likely bent/warped. Personally experience is a warped feather shaft is more likely to cause low speed vibration, a good example is spooling up of the heli.

Another easily overlooked part is the uneven tension of the main rotor blades on the grips. When one blade is tighter then other, on spool up, it will create strong vibration/wobbling due to uneven movement of the main rotor blade along the axis of the main rotor.

The flybar itself when unbalance will also results in this sort of behavior.

Link rod on the rotor head can also be damaged during a crash. It is best to check that your blade pitch are aligned correctly. If there is too big a difference, it will affect tracking as well as vibrations as one blade will have lesser resistance that the other.

[TiFische]

The Chicken Dance

Misato, yup the chicken dance sounds about right. I suspected about the main & feathering shafts but never thought the tightness of the grips would have such an impact ... that one I'll definitely need to take a look.

The flybar was the first thing I checked ... and that looks fine.

Will walk through the pieces tonight and see if I can make the vibes go away

Thanks guys

Violent wobbling / vibrations on spool up aka what i called as chicken dance can be caused by a lot of factors. Usually in a crash, the main shaft and the feather shaft are one of those things that usually breaks(bents/warp) from the impact.

The more accurate DIY checking of these 2 shaft is to roll them on a flat glass surface and listen to the sound produced, it helps if you have a new shaft to compare against. If it does not sound consistent, its likely bent/warped. Personally experience is a warped feather shaft is more likely to cause low speed vibration, a good example is spooling up of the heli.

Another easily overlooked part is the uneven tension of the main rotor blades on the grips. When one blade is tighter then other, on spool up, it will create strong vibration/wobbling due to uneven movement of the main rotor blade along the axis of the main rotor.

The flybar itself when unbalance will also results in this sort of behavior.

Link rod on the rotor head can also be damaged during a crash. It is best to check that your blade pitch are aligned correctly. If there is too big a difference, it will affect tracking as well as vibrations as one blade will have lesser resistance that the other.

[misato]

Forget to add... look out for a worn out damper as well.

[JYZoom]

u may wish to look at the one way bearing but I dun usually bother to check unless I hv crashed it over 5X

This was the problem for me when I chased for one weeks where my not visible vibration that my flybarless VBAR electronic is telling me. AFter changing the one way....the VBAR is very happy now.

One way is to remove all blades and sping it up to make sure it is not cause by the blades....but it looks more like main gear systems ( spindle, shaft, bearing and one way ).