Latest Trex 700x tail gears fail !!

[Lightningrc]

Around 2 years ago Align cost me the price of a new kit on my then new Trex700x.
I made sure to buy all there updated cases was running the latest with new red gears shimmed .
The tail was working hard doing up right hurricanes then it happened again !!
The area it happened I had no choice to just get it down !!
Another load of money Align has cost me .
This time I’m jumping ship !!
Not even a reply to my email which I sent 3 days ago !!!

[Tnjet]

LightningRC,

Can I have your old housing, bearings and gears?

TNJET

[Lightningrc]

Yes if you cover the cost of new cases because I have already just spent another £400 on repair parts 😞 and not happy .
Also need to cover cost of shim kit and shipping to you .
Cheers Steven

[HeliSmith]

I thought I remembered red torque gears being problematic, but when I googled it I came up short. Though it is late here.

Align is a great brand as long as you understand that even though they do their best to catch all problems before release it hasn't been possible to do so in all cases. In lieu of that I recommend joining any dedicated forum section as well as the appropriate Facebook group so you are able to remain informed.

Align is a great flying helicopter, typically on the edge of the available technology so while they have terrific pilots testing their innovations all over the world some things may be missed in some cases. After someone crashes due to an engineering problem it's a hard sale to get them to reconsider that brand. But those who are patient to allow others to go first and carefully peruse the proper forum sections can generally reap great rewards by choosing Align.

I'm not sponsored by them or anyone at this time by the way just rambling at 1 in the morning lol. I am sincerely sorry about your losses. Always follow your heart it's the only reason we do this.

[Smoggie]

I’m not bashing Align here, I own three including a 700x and like them a lot but this weak TT gear issue has been reported regularly for several years. In that time Align have introduced a few new models of the 700, three different colours/materials for the gears (white then black now red) and an upgraded tail boom case....
Still the problem persists. How many years and attempts do they need to fix it properly?

[Lightningrc]

Yes exactly plus this is the second time now plus I bought all the versions of the gear upgrades then they released 3 versions of the case .
The case must still be flexing under load because this fault did not happen on the wider older versions !!
The only fix is for an aluminium front gear box housing .
Align have still not answered my email and I resent it again last night and nothing !!!
Align has a company suck .
Sab are more expensive but they’re after service is superb .

[HeliSmith]

I agree with you guys and also it's not like I am asking for them to replace it for free, even though that should happen. But only to make the upgrade available! On my Align 470 I had to upgrade to the torque tube because I was having problems with belts.

Anyway I have Goblin 380 and 700 they fly amazing! I have the Kyle Stacy version servos in my Goblin 700. Definitely worth the money if you're into 3D and so far on my 1st crash none of them stripped! I want to move over my electronics to a Kraken eventually but I still love my Black Thunder atm.

Also just FYI there are new helis on the horizon such as Synergy 696. I don't know about spares costs, or much about it at all yet.

[ic-racer]

Around 2 years ago Align cost me the price of a new kit on my then new Trex700x.
I made sure to buy all there updated cases was running the latest with new red gears shimmed .
The tail was working hard doing up right hurricanes then it happened again !!

I would determine the number of hours on those gears and then replace them at one-haf that interval. In your case was it two years? So maybe replace them every year?

I'm up to 36 hours on my Trex 700 and my red gears still look pretty good.

[Lightningrc]

2 years no since then I have bought the 3 upgrade versions of the gearbox cases and new red gears every time , last done 6 months ago and checked gears 3 weeks ago and they had light wear only .
Both times Helicopter 🚁 has failed doing upright funnels anti-clockwise .
I’m not the best 3D pilot but I can do these no problem .
When your doing them you can hear the tail working hard .
Also do these with my Sab models and never ever had a failure

[HeliSmith]

Originally Posted by Lightningrc

2 years no since then I have bought the 3 upgrade versions of the gearbox cases and new red gears every time , last done 6 months ago and checked gears 3 weeks ago and they had light wear only .
Both times Helicopter 🚁 has failed doing upright funnels anti-clockwise .
I’m not the best 3D pilot but I can do these no problem .
When your doing them you can hear the tail working hard .
Also do these with my Sab models and never ever had a failure

Interesting that it always fails doing upright funnels anti-clockwise. It seems like maybe there is some binding or unfavorable angles. When you setup your tail and got it center was their anything notable? Also, when setting the end points for your tail did you get fairly close to equal throws? What flybarless unit does it show you the actual value for tail endpoint adjustment?

[Smoggie]

Originally Posted by HeliSmith

Interesting that it always fails doing upright funnels anti-clockwise.

That's only as you would expect. An upright anti-clock funnel (on a heli with clockwise main rotor) demands greatest thrust from the tail rotor. The thrust needed to fly sideways at high speed and the thrust needed to counter torque are combined in this manoeuvre. The tail blades are at very high pitch angle and load on tail drive is at maximum. This is the same for any heli, it's just physics.

Dont try to infer that this is a setup issue....

[Lightningrc]

No it’s not a set up issue but the tail drive system should take this !
Yes it is demanding the maximum load on tail but these are what they are designed for .
Like said I do this regular on all my other helicopters and used to do them on my 700DFC and my 700 nitro and now do them on my Sab also .

[HeliSmith]

Originally Posted by Lightningrc

No it’s not a set up issue but the tail drive system should take this !
Yes it is demanding the maximum load on tail but these are what they are designed for .
Like said I do this regular on all my other helicopters and used to do them on my 700DFC and my 700 nitro and now do them on my Sab also .

I only meant that possibly there was some problem that is causing this only happening when the tail is in this position. While I understood it is maximum stress I wasn't considering this stress as the cause of the failure.

Let me explain my thinking another way.

Possibly the tail limit setting in that direction is over. So the tail hub is jamming up. Or possibly something happened with the tail control rod holders, they are spinning on the boom at maximum tail travel in that direction. Or maybe there is a dirty control arm surface, bearing, and etc..

[Lightningrc]

I understand what your saying but the cause is still the front tail gearbox cases are not strong enough .
Align have made three upgrades of theses cases trying to fix the problem but the cases are still flexing under load causing the gears to slip and wear out very fast when they give way .
Only answer would be to have aluminium cases .
It does not happen on the older models because the cases are much wider in the bigger frames .

[Dennis Everett]

which ratio gears were you running ? some have has gear issues if the gov isnt set properly , also if gears arnt shimmed correctly you could have a problem , nothing lasts forever , should be changed out once in a while , that all being said , i never had any problems with my 700x .

[flipboy]

I have the Align 700 Dominator DFC version with the black gears,i fly it very hard (pop and lock smack with big air) and its had hundreds of flights,bought it used in 2016 from another heli forum.I have a topic about this in the main discussion titled:
Slight Crack On Lower Frame
My black front torque tube gears finally stripped after hundreds of flights,managed to auto down with minimal damage.I recently bought the red gears to replace the black ones that stripped,hopefully these red gears will hold up just as long as the black ones or even longer.I would like to mention also that i have an aggressive high gain on my governor gain using the Neo Vbar governor,i've flown that way for hundreds of flights maybe that could have been a contributing factor to the stripped gears?
I fly at 2100 headspeed,so i've turned down my tail gain to about 50 in the Vbar tail gain menu and run 115 tail blades.