T-rex 450 pro V2 serious tail bearing problem

[Spork01]

Originally Posted by Raydee

I have been looking for a upgrade tail that will work on the 450. So far the Protos tail looks like a option. I looked at the Beam tail and it looks just like the Align design...actually the whole heli looks like a Align.

The beam tail is very similar to align but the slop is no where near as much as align and the tail grips doesn't lock up like align .

[Raydee]

Here is a vid of mine with new tail bearings. On the bench everything is very smooth and the tail slider moves both ways without a problem. As soon as the the tail blades are spinning and there is any pressure on the bearings the slider jams up with left stick input.

[ame]http://www.youtube.com/watch?v=0W-JavePHAU[/ame]

[Wesley888]

You need to move those 2 plastic tail control guides around so that the flexible steel rudder push rod doesn't bent like that. It'll be much stronger to control the tail when it doesn't bent, or at least it doesn't bent that easily. Mine are at about 1/4 and 2/3 position starting from the body.

[Raydee]

I have moved them in a bunch of different spots, the problem is the tail is locking up under load. I was even going to try a carbon rod next but I disconnected the rod all together and when i try to push the rod there is MAJOR resistance.

[Vinno]

Had my first inner bearing fail, just replaced it. In flight hover I notice little rudder movement and tail not holding in a slight move of pitch changes, brang it down and giving full inputs, jammed up the control rod. Couldnt even move it by hand and knew it had to be bearing.

If i was doing any 3d, still newbie, would of crashed it.

Raydee how did you lock your heli down, just take off the main blades? Going to try the same before i take off to the air again.

[Raydee]

yes I just took the blades off and held the heli down.

[trexpro]

Hi guys,

Just an update of my bird with the Protos bearings

After 155 flights my tail bearings buckled and I replaced mine with Protos bearings.
I have now 225 flights on my bird, so that is 70 flights of no problems so far.

I check my tail after every flight

I still suspect that the bearings are the problem, how else do you explain that I've made 155 flights with the original Align bearings? luck

I also had a 450 V1 (which have the same blade grips) with more than 200 flights without problems. (I sold this one).

Danny

[Raydee]

Its very possible that a good set of bearing may mask the design problem for some time. I ordered some Boca bearings and I also have a couple different tail setups that I am going to try.

[trexpro]

Originally Posted by Raydee

Its very possible that a good set of bearing may mask the design problem for some time. I ordered some Boca bearings and I also have a couple different tail setups that I am going to try.

I agree with you, that this tail is not the best design. Align had better design a tail with thrust bearings and a better tail pitch slider / bel crank.

But we have to deal with this design and the bearings replaced for quality bearings is in my opinion a good solution.

Maybe Align will learn from this design flaw for the next generation 450 heli's let's hope so

For now, always check your tail after every flight.

[Spoto]

Originally Posted by trexpro

I agree with you, that this tail is not the best design. Align had better design a tail with thrust bearings and a better tail pitch slider / bel crank.

But we have to deal with this design and the bearings replaced for quality bearings is in my opinion a good solution.

Maybe Align will learn from this design flaw for the next generation 450 heli's let's hope so

For now, always check your tail after every flight.

Well, except I've gone through....3 sets align, 2 sets boca stainless, and 1 set boca ceramics in about 45 flights. I was going to try a new set of grips next.

Or is it how the bearings mount in the grip's? Do they need to be secured with ca or locktite?

[trexpro]

You do not need ca or locktite to mount the bearings.

Note that if you replace the tail bladegrip bearings that you dont turn the screws too tight,and be absolutely convinced that there is no play between the blade grips and the tail rotor hub and that you can turn/rotate the grips without feeling the bearings (if you can feel the axial load on the bearing,than you have turn the screws too tight), let the loctite do the job, but watch out that no loctite touches the bearings!

But in your case I do find it strange that so often the bearings fail, maybe there is something wrong with your blade grips

[waqr]

Originally Posted by Wesley888

You need to move those 2 plastic tail control guides around so that the flexible steel rudder push rod doesn't bent like that. It'll be much stronger to control the tail when it doesn't bent, or at least it doesn't bent that easily. Mine are at about 1/4 and 2/3 position starting from the body.

I also have the problem that the connecting rod gets slightly bent (up towards the tail boom) by the tail control guides. I would need to have longer control guides in order for this not to happen. How do you all solve this issue?

[trexpro]

Originally Posted by waqr

I also have the problem that the connecting rod gets slightly bent (up towards the tail boom) by the tail control guides. I would need to have longer control guides in order for this not to happen. How do you all solve this issue?

To solve your probleem jou can order the Carbon push rod


http://www.ac-rc.com/product_info.ph...284ksjrkhbtab5

Look at my heli
it is a much stronger push rod, he will not bend

[ryem3]

Easy to use a carbon rod without the guide on a 450, the rod is not that long. Your setup looks like there is a lot of rod deflection.

waqr, looks like you are getting a lot of binding, the control rod should not bend like that. Your tail servo should only move to the limit of the slider and stop. Set your tail servo endpoints to that the servo stops when the slider reaches the end. You should not hear your tail servo buzz when you are fully turned.

[trexpro]

Originally Posted by ryem3

Easy to use a carbon rod without the guide on a 450, the rod is not that long. Your setup looks like there is a lot of rod deflection.

waqr, looks like you are getting a lot of binding, the control rod should not bend like that. Your tail servo should only move to the limit of the slider and stop. Set your tail servo endpoints to that the servo stops when the slider reaches the end. You should not hear your tail servo buzz when you are fully turned.

That's not entirely true, if you use this type of carbon rod without the guide it will bend.
You need a thicker carbon rod to use without guide.
The deflection you see is minimal, and is absolutely no problem for the operation of the tail.
I have flown without the guide and with the guide, and the best option is to use te guide, yes you get minimal deflection but you have vibration without the guide.
If the control rod is bending to much, you have a binding problem. convince yourself that everything moves without friction and than you can connect the push rod.

[waqr]

Well, the problem is not that it is binding or anything in the endpoints. The problem is that the steel connecting rod is tilted down in an angle when getting closer to the servo due to that the servo is located further down than the tail. Is this a problem? I guess it has to be like this for all of you guys with the Pro version.......

[trexpro]

Originally Posted by waqr

Well, the problem is not that it is binding or anything in the endpoints. The problem is that the steel connecting rod is tilted down in an angle when getting closer to the servo due to that the servo is located further down than the tail. Is this a problem? I guess it has to be like this for all of you guys with the Pro version.......

It is true that the servo is located further down than the tail, on my picture you can see that the carbon rod have a minimal deflection because of that.
It is not a problem that the steel connecting rod is tilted down in an angle, it's just the design of the tail servo mount. the T-rex 550 has the same tail design. you can fix this by using a longer tail linkage bal on the tail control arm, then the control rod is equal to the tail boom if you know what I mean

The bottom line is that the 450 pro suffers from some design flaws, Align should pay more attention during the design of their heli's. Furthermore, it is just a very nice helicopter for a good price.

If you expect more from a helicopter, I'm afraid we must put more money on the table for example, a Logo, or Henseleit.

[Jamison816]

I can't get my tail to hold at all could this be tail bearings? Sorry For the noob question but I'm frustrated I've flown my 450 several times had I small crash main shaft, blades, and ball link rods and now on spool up it spins outa control! Any advice would be awsome thanks.

[dfbonney]

Originally Posted by Jamison816

I can't get my tail to hold at all could this be tail bearings? Sorry For the noob question but I'm frustrated I've flown my 450 several times had I small crash main shaft, blades, and ball link rods and now on spool up it spins outa control! Any advice would be awsome thanks.

Your issue sounds more like set up. Might want to go through your gyro setup and other menus if you're on 3GX.

[trexpro]

Originally Posted by dfbonney

Your issue sounds more like set up. Might want to go through your gyro setup and other menus if you're on 3GX.

+1 sounds like a reverse problem. check your setup