700N Strange tracking issue.

[gazza]

Hi all.

I seem to have a weird tracking issue with my 700...
Namely, In all flight modes the tracking is out but on one side only
Hovering tail in, the left side of the rotor disc is fine but the right side is about 5-8mm out at the blade tips.

I'm stumped!!
I must add that this Heli has been in the dirt a couple of times during it's previous life. But even if something was bent surely it would show on both sides of the rotor disc as the blades spin

As ever any pointers will be much appreciated

[Made2Fade]

Dampners? Or bearings in the main grips. Thrusts even.

[gazza]

Dampners? Shot in maybe one side only maybe. Or bearings in one of the main grips. Thrusts.

That did cross my mind mate but surely it would show on both sides of the disc as the shot dampener changes sides as the blades spin

[Made2Fade]

Or paddle alignment or bent flybar In fact my money goes on this TBH
As this will show up on one side only. Check this out (first paragraph and diagram on the right) - http://www.raptortechnique.com/bladetracking.htm

[gazza]

Hmmm the paddles are aligned and the flybar is new..
I'll check the flybar cage tomorrow to make sure it's not slightly bent or twisted in any way and realign everything again

[Made2Fade]

TBH though most other obvious things... ie bent main shaft/feathering shaft you are likely to see show bad tracking on both sides as you say. Intrested to see what it turns out to be now then mate

[Tim Procter]

Those Torsion blades gazza.

Try some different blades I'll bet that sorts it.

[kamikaze]

The only thing I can think of is that can cause this is a combination of bent feathering shaft and bent mainshaft/rotorhead/F ball on the blade grip.
Unfortunately for the disc to be out of track on one side only it would have to be a combined effect of 2 faults and therefore harder to trace.

Good luck mate,hope you get it sorted.

[jiberjaber]

...or bent mixing arm / ball on mixing arm.

[t-rex pedro]

As Tim says, whack another set of blades on there first and see if that helps. If the heli has been decked a couple of times chances are the main/feathering shafts are new so I would look at the balls on the blade grips, especially if you still have the head button on there. Take them out and if you see any twisting on removal then you got a bent one. Had the exact same problem with my 600 before.

[SRH990]

My 700 has bit the dirt 3 times so far and each time I've checked the feathering shaft and each time its been straight - being 10mm diameter really helps

Even so, if you haven't replaced it after a crash and now you're having tracking problems I'd replace it anyway but my money is on paddle alignment/bent flybar.

[mattie-lodge]

Gazza,

I reckon go for a the blade change as well.

I recently stuck my 600n in. After the rebuild I decided to try a set of the new Align wood core blades. First flight the tracking was miles out, so I adjusted and flew it and 30 seconds later is was out again. I was convinced it was something I did in the rebuild.

Went flying again after feather spindle change and numerous other things changed, and Richie said why dont you stick a set of Radix on it.

BINGO!!!! Problem gone. Dont ask me why, but now its fine. Interesting because I've heard nothing bad about these Align blades at all. Perhaps I got a duff pair, however I had exactly the same thing with a set on my 500 as well. Changed and put Radix on and the problem went away

[t-rex pedro]

I've just got a set of Align blades to try. Always used Radix as they track perfectly as Mattie says but they are also £20 more expensive. At the moment that's a bit much to swallow for my 600 hack which i'm trying new things with. I have radix on all my other helis though. Fingers crossed the Align Pros work well for me.

[gazza]

Thanks for all the advice guys
Everything is aligned and straight. Mixing arms are straight as are all the balls including the balls on the grips and the flybar cage is straight also.
Well actually one of the paddles was slightly out, must have been knocked in carriage
The flybar and shafts are all brand new. The main blade grip bearings are a little notchy and the dampeners have seen better days so I'll fit some new dampeners and bearings and if that doesn't change things I'll fit replacement blades and report back

[Matt Gill]

I have had this issue a few times and it always seems to be fixed when I change the thrust bearings for a brand new set (providing everything else is straight, shafts etc. Thrust bearings can feel ok and look ok, but they do wear and can suffer damage from a crash.