torque tube bearing oriantation?

[tonystevens]

does anyone put the t/tube bearing anywhere other than the manual suggests?
Manual says to put it 5-7 cm from the centre,towards the heli.
The reason i ask is that if i put the t/tube in back to front the tube runs straighter this way.I dont think ive ever had a t/tube that spins perfectly straight,saying that its only ever a slight wobble.
Can anyone see a problem with me doing this?

[tourerjim]

I centre the bearing on the TT with clue once dry then slide her home job done.

[GravityKills]

the reason for asymmetric spacing is resonance: You don't want both sides of the torque tube to resonate at exactly the same frequency.
I do exactly as the manual says, and haven't had any problems.

And, yes, the bearings should be CA glued to the torque tube, spray grease / silicon oil to the inside of the tailboom before putting it in.

[Tom Burgess]

I centre the bearing on the TT with clue once dry then slide her home job done.

thats not a good idea

[Mart61]

I'm with GK. It's all about resonance. So long as the bearing is not in the centre of the torque tube, I don't think it's make any real difference if it's closer to the front or, if the TT is put in the other way around, the back.

[GravityKills]

if there was something between the lines that I missed, please forgive my ignorance.
Otherwise, from the manual (700): "Please apply some CA glue to fix MR 148 bearing on the torque tube, avoid CA glue adhering to the dust cover or it may cause the bearing stuck. When assembling into the tail boom, please apply some oil on the bearing holder and press the holder into the tail boom horizontally".

To my delight, their English is almost worst than mine...

[Mart61]

Nope, your interpretation of the manual and your earlier post are spot on.

[Tom Burgess]

I would put it closer to the front Tony, after all, that is where the drive is coming from

[tourerjim]

thats not a good idea

Why!
Reason I centre the bearing & is my way of thinking theirs end float on the TT although the bearing sleeve probably wont move but you cant be sure that the TT wont move to one other end of the gears also the torque on the gears is as great both ends so Im not sure which way to off set the bearing.

[Tom Burgess]

Why!
Reason I centre the bearing & is my way of thinking theirs end float on the TT although the bearing sleeve probably wont move but you cant be sure that the TT wont move to one other end of the gears also the torque on the gears is as great both ends so Im not sure which way to off set the bearing.

resonance, set your your tail pushrod guides at exactly centre to each other and watch for the sine wave form

[snapshot]

If it's equi-distant i.e. centered it can induce resonance, which will induce vibrations!

As to which end to place it, I always place it closer to the heli. My reasoning that end is being driven by the motor, the other end is driving the tail rotor.

maybe illogical and nothing to do with anything, but the manual suggests it so why go against it.

[tonystevens]

cheers lads. think ill leave it the right way round for now. Its only a slight wobble anyway.Ive got a shake on spool-up that shows on the tail fin but dissapears when in the air ,any thoughts?