Vibration on spin up & down

AndyRRR · Fully Charged Joined: 02 Jul 2011 Posts: 4

Afternoon, I'm a newbie to this hobby and have followed the advice of a few video's and worked my way up. Started off with a T-34 twin blade job and got bored of that quite soon. Then got a honey bee v2 to practice on a fixed pitch helicopter. Few crashes & builds later my confidence was building.

Now finally I have a belt cp v2. Been pottering around in the garden with it and started to get a bit cocky (I know I should have gone to the park) but clipped the garden fence with the main blades.

Now on spin up, it shakes around really bad. Ok when it gets up to take off rpm. I've check the linkages etc and noting seems to be bent or out of shape. Have I bent something that's not obvious?

Thanks,

Andy T.

Scott · Extreme 3D Joined: 11 Nov 2010 Posts: 340

Welcome Andy,
I am not familiar w/that Bird, but my guess is that You have
bent the feathering shaft/spindle slightly, and/or the main shaft,
provided as You stated, that no damage is visible to the
blades. Either fix should be very cheap, but will require
patience & determination, which most on here will agree
is part of the fun in this hobby. Are parts readily available
for that heli?
Scott

AndyRRR · Fully Charged Joined: 02 Jul 2011 Posts: 4

Thanks Scott, I've been having a read and looks like it might be the blade tracking. Altho I have noticed that there is quite alot of play in the blades. If you pull the blades gently down you end up with them looking like this ^ and up they look like this V. Without adjusting any linkages, blades look fine.

Is that the feathering shaft?

Thanks in advance.

Andy.

Scott · Extreme 3D Joined: 11 Nov 2010 Posts: 340

The feathering shaft is a straight metal rod that runs perfectly
in line withe the blades & blade grips. Again, I am not familiar
w/Your heli, but regardless, if this shaft is not perfectly straight,
(as new) it will cause balance & tracking problems. If Your heli
is collective-pitch, this shaft will have thrust bearings & washers
etc., that will have to be replaced exactly the same way, when
You replace the shaft. It is a tedious job, but on My heli, the
shafts are 2 for about 6 bucks, so the cost is really not an
issue. It`s more about patience, & parts availabilty.
Bottom line, tho.....If You want to fly R/C helicopters, You
have to be willing to work on them, because You WILL crash.
I have 2 needing repair now, but will most likely wait till winter,
when I can`t be outside.
Scott

nick_onelove · Posted: Sun Jul 31, 2011 2:29 am Post subject:

You mean that it shakes more on start-up since the crash right? I've got a Belt-CP X and the cheap ESC doesn't start very softly at all, causing pretty severe vibrations until its up to speed.

If it is much worse since the crash though, I would try replacing the feathering shaft and getting the blades in track and then the main shaft if that doesn't work. I'd be pretty surprised if a crash that didn't even damage the blades bent all that aluminum though. Confused

Scott · Extreme 3D Joined: 11 Nov 2010 Posts: 340

Last winter while playing around in the Mancave, (Basement)
I knicked the wall w/My B-400. Virtually NO damage to the
blades, but bent both the feathering shaftr, & the main sharft.
Made a helluva "whack" sound, but no damage was visible.
Carbon-fiber rotor-blades tho. Gonna stick w/wood blades on
the 450 till I get things dialed.

chopper54 · Posted: Sun Jul 31, 2011 3:52 am Post subject: post subject

i recently got a new bnf blade 450 and the first few flights had the shakes as i spooled up the same symptoms as yours. i removed and balanced the blades and the problem was cured. you may have done enough to unbalance your blades but i agree its more likely to be the feather shaft.

laneritc · Posted: Sun Jul 31, 2011 3:58 am Post subject:

Hi Andy lane here I have a belt cp also I agree with Scott bent featuring shaft I get mine from rely helicopters 2 for $5.00 also you need 2 5.5mm nut drivers to replace shaft there,s a link to order them there also lane
_________________
first to the scene of the crash
Walkera CB180Z V200D01 MX400 QR ladybird 4G3
Esky King 3 Esky belt cp v2

laneritc · Posted: Sun Jul 31, 2011 7:57 pm Post subject:

That's suppose to be esky helicopter finger went stupid
_________________
first to the scene of the crash
Walkera CB180Z V200D01 MX400 QR ladybird 4G3
Esky King 3 Esky belt cp v2

AndyRRR · Fully Charged Joined: 02 Jul 2011 Posts: 4

Thanks guy's i've ordered some parts, just the wait now........decided to order some more just in case. It did make a hell of a noice. I think the feathering shaft is the culprit.

Cheers,

Andy T.

pjdog · Posted: Wed Aug 03, 2011 12:05 am Post subject:

Have you done q main blade balance?

Jack
_________________
RC Submarines (3)
RC Planes (20)
RC Boats (3)
RC Helicopters (5) B400-EXI 450 pro-EXI 450-MSR-MCX
DX6I (2)
AMA-952547

AndyRRR · Fully Charged Joined: 02 Jul 2011 Posts: 4

It was the feathering shaft, it was so bent out of shape I couldn't believe it. One of the gears was out of shape too so decided to replace that and the main shaft also for good measure.

All fine now....... setup and charging.

Off to the park tomorrow Smile

nick_onelove · Posted: Sun Aug 21, 2011 5:53 am Post subject:

Good to hear! Good luck tomorrow!
_________________
Align: Trex 250 3GX + Trex 450 Pro with Vbar
Blade: 450 X, mCP X, 120 SR, mSR X, CX3, mCX2
Esky: Belt-CP X and V2 - Futaba: Heli-Max Axe 400
Walkera: V500D01, M120D01, V100D08, DEVO 8
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