T-rex 700 Ratio Mod.

[callum]

I take no credit for this,

Credit Goes to Simon Brown and Noel Cross.

"Hi.
I took a picture of my trex 700 rotor head in an attempt to show the bolt / pivot that has been moved, creating and incredible change of accuracy. I can't stress enough just how amazing this mod is. My 700 rolls straight down the boom with no mixing and no elevator input, forward and backwards rolling!.
And it is now accurate where as I personally found it a little hard to tame when requiring smooth manouvers. Now it is a piece of p.. to put exactly where I want.

THANKS TO NOEL CROSS and his years of FAI competition experience, this was his idea, trialed initially on a current FAI pilots trex 700.
So here is the photo. Basically all you do is remove the flybar cradle and drill a new hole further out, so that the mixer arm screws in further from the center of the head, thus when the flybar tilts, there is more input to the main blades.. The red arrow points to the bolt that needs to move out and this shot is after the modificiation.
"

[Paulo uk]

Interesting, I find my 700 more accurate than my other aligns (which not not say much for align heli accuracy!!) - anyone else tried this?

P

[choppertastic]

Not tried it yet but I am interested in it as I have a 700 and want to fly the sportsmans with it...

[SLIPPERY STEVENS]

Does this work for 3D as well.?????

[Geek]

how much does it need moving?
if you can measure it from the old hole or to the end of the cradle.
also was it a newish model you did the mod on? just checking Align haven't changed it since.

interesting mod
wonder if it would help any other models

[moyesboy]

The 600n has a choice of holes there. I was inadvertantly flying my two 600n with alternative setups. I hadn't noticed any difference between them.

This isn't a phasing mod surely - it affects only the flybar ratio and not the phasing?

[Steve]

Hang on a minute.

This is not a phasing modification.

It increases the flybar ratio to make the heli more suitable for FAI flying (i.e. Noel Cross' stylie). The increased ratio makes the heli self-correct to gusts of wind better as the flybar has an increased input into the blades. It's not suitable for 3D flying as it increases stability. For 3D, you generally want to decrease stability.

You can get the same effect without drilling anything by fitting the G-Force 700 mixer arm set which gives various mixing options (I've got this on my 700) ranging from FAI style to more aggressive-than-standard 700 3D style.

[Andy from Sandy]

When I first read the title I wondered why would you need it as the model flys pretty darn good to me.

If the model does however have a phasing problem I think you just need to move the elevator A arm on its shaft.

[Eckchaz]

I have to agree that I dont think this is a phasing mod (after my last thread, I learnt alot about phasing! ) I also agree its got to be the elevator A arm to adjust the phasing!

This is already on the new lines of Align 600's. theres two holes you can choose from.. even in the Align manual.. it states the closer hole is for more "Nimble" heli and the outter hole as of your photo is for more "stable" heli! Yes you can still do 3D but its not as "active" as being on the inner hole as per the Align manual!

[callum]

Heya All,

My Bad, I had skimmed the article and assumed.

Title Changed

-Callum

[heliward0]

i will have to try this mod on my 700 FBL see if its any good.

[barney]

The Trex 600 has had this option from its inception although I have never tried it on a 700. Ive always used the inner hole myself as I alter the upper SF arms to reduce the swashtilt and travel which IMHO helps the 600 fly a little better.

The one thing I have yet to try is flipping the main blade grips to leading edge control as I find the collective a little to snappy round midstick. I'm undecided about this as I'm thinking the difference is really how the main blades are weighted C&G wise. Using a FBL system would possibly remove this as it is more linear.

I also have a dead spot as I prefer moderate H/S where I get some blade cavatation, The only real get around to date has been upping the H/S

brian

[Swashbuckler]

i will have to try this mod on my 700 FBL see if its any good.

eh? how and why? If its FBL you won't have a flybar seesaw surely?

[Nick B]

ROLMAO

[Steve]

eh? how and why? If its FBL you won't have a flybar seesaw surely?

Shhhhhhh, don't tell him that...... I want to see him try it.