Torque Tube Setup

[coptermanic]

Just re-measured, the mid-bearing is 4.6cm from rod mid-point

[J-S-Q]

On the 700LE I've just built, the backlash is pretty much fixed due to the tail being pinned in a predrilled hole. I was surprised to find that there is almost zero backlash in the torque tube -just a tiny fraction which is almost undetectable. I'm awaiting some good weather for the maiden flight so can't comment yet how well it runs like this but I haven't heard of any complaints.

[ChrisP]

On the 700LE I've just built, the backlash is pretty much fixed due to the tail being pinned in a predrilled hole. I was surprised to find that there is almost zero backlash in the torque tube -just a tiny fraction which is almost undetectable. I'm awaiting some good weather for the maiden flight so can't comment yet how well it runs like this but I haven't heard of any complaints.

Had no problems with my LE mate. Had about 14 flights with it now

[Nick B]

Just re-measured, the mid-bearing is 4.6cm from rod mid-point

Best to put the shorter half of the tube towards the frame,also from memory the manual says 5-7cm,i opted for 6cm

[coptermanic]

Bit of a dichotomy here, as the TRex 600NSP manual states 5 to 7cm to forwards of centre, and the Align TT sheet which came with the TT states to "fix it 10 to 15mm off centre"

[rapidgaz]

hi mike, when i built my 600 i had no gap at all, cause i did not know, but it went thru a season and half with no problems, and as w 1 post says the 700le you cant make a gap because of the pre drilled pining, plus never gets to warm in sunny uk, so when built in the house its not far of the summer heat, so would not think there would be that much expansion on carbon and the plastic gears.

[coptermanic]

I was wondering why much play would be needed, it's not like the boom is flexing much. And you can't do much with the umbrella gear meshing either, apart from lube. Has been too wet n windy to test fly in the garden here.

[Nick B]

Think its more about stopping unwanted vibes,mate

[coptermanic]

Wonder why there are not 2 bearings within the tube, splitting it into thirds, and less chance of resonance?

[Nick B]

Believe there 2 on the 700

[rapidgaz]

there are 2 on a 7, but the off center bearing in the boom is to stop that on the 600, i cant remember which way round it went but i thought that the bearing went off center towards the front of the heli, cant find my old manual now mike and could not download of the align site.

[Geek]

Wonder why there are not 2 bearings within the tube, splitting it into thirds, and less chance of resonance?

you need 3 different lengths to help with resonance.
lots of people used to use 2 bearings
try it. it can't hurt