wobbly 700

[LipolyGone]

my 700 has the wobbles, seems to shake the whole under carriage side to side.
Not flown it 6 times yet and it didnt do this on the first few flights i had with it.
It's not had so much as rushed landing or been in the dirt either so what could it be?

[Aidi]

Check the boom supports Martin. They have been known to cause some pretty nasty vibrations.

[Jamin_00]

Yes I had this,boom supports loose

One came out during flight causing a tricking landing as it was hanging down.

[LipolyGone]

it could be boom stays.
Seems to shimmy from the top of the main mast all the way down to the skid's tho.
I'm wondering if i should have bought and fitted the washers every one talks about.

[agh321]

could it be a too low a head speed ?

[bish]

it could be boom stays.
Seems to shimmy from the top of the main mast all the way down to the skid's tho.
I'm wondering if i should have bought and fitted the washers every one talks about.

Save your money its not a washer problem my guess is head speed low

[glen_j]

i had a similar thing with my 700 when i was running a couple of tanks through it after i rebuilt the engine and it was running really rich, as soon as i leaned it a bit and the headspeed came up it stopped doing it

[choppertastic]

Might be that the head speed is to low for the hard dampers.

[trvo]

I've seen his 700 do this, it's not low headspeed. When my 600e started doing the same thing it was the mainshaft bearing blocks that were sloppy. I seem to remember some sideways play in your bearings?

Trev

[robgt]

Just a thought here...
I've seen a full body shimmy on the Trex600 and it came down to the frames being worn out making them weak.
We found this by putting a hand on top of the frames to hold them firmly, and then grabbing the head and rocking it side to side - there was a lot of movement!

Might be worth a check to see if your 700 has done the same?
Cheers,
Rob

[LipolyGone]

AS trev said there is a slight movement side to side if
you grab the frames & try to rock the head.
Should I need to replace the bearings after only 6 flights tho?
The first 4 flights were with a head speed of 1850
as per norm raptor 90 kind of set up.
Then I took it to charlton & was advised to ramp the headspeed up to 2000
to bring the cyclic speed up a little.
I duly did this & after a further two flights the problem developed.

[robgt]

Should I need to replace the bearings after only 6 flights tho?

It's possible??
I take it this kit was new and is now only 6 flights old without any knocks?
That would suggest something was a tad iffy somewhere to begin with, if it is indeed the bearing blocks or bearings.

I can't see the headspeed being a problem here - many people run that headspeed.

Perhaps there was a bearing issue that was aggravated by the higher headspeed though?

Cheers,
Rob

[LipolyGone]

yes the kit was new and built buy myself rob.
Any tips on getting these bearings out?
Think i will change them out first then
delve deeper if i still have issues.

[robgt]

I think you'll need to heat up the bearing block to get the bearing out?
I've not looked closely at one for some time, but I assume the bearing is a tight press fit into the block?

Do the bearings appear to have any sideways play in the bearing itself or between the bearing and the block?

If not, this might not be the right place to start work?

Are the blocks securely fastened to the frames also?

Cheers,
Rob

[LipolyGone]

Your right Rob I think I'm going to have to slowly work my
way through the heli checking for loose bolts etc first.
Maybe pull the mainshaft out of it & double check those bearings.
If I still cant find anything I may need to start
replacing bearings.
Thanks for the advice guys.