rrTV-PHOTO   New HD TV
HOME   rrTV-PHOTO   GALLERIES   MY GALLERY   HELP-FAQ
myHOME PM pmRR MEMBERS 776 ONLINE 19 EVENTS SEARCH REGISTER  START HERE
 
1 page502 viewsPOST REPLY
JR-Spektrum . Gyro Hobbies . E-flite

.
.
Align T-REX 600N 700N > What did i do wrong? Interaction!?
 
 
SkateFreak
Key Veteran
Location: Cambs UK/Luton

Hey,
So I'm running a T-rex 600N Sport off a DX7 with a throttle jocky pro, 720, Hyper/MP2, 9451's on the cyclic running at 5.1 off a duralite 2100 regulated lipo setup.
My poor raptor committed suicide a short while ago so i got this rexy airframe to get me flying...
I'm just getting used to it now and discovered as i start to throw it about more that when i do a nose in inverted punch out the heli doesn't come out straight?!
I very much doubt its a latancy issue because its constant and you would expect the lagging servo to eventually catch up (if left it would probably come right back down on its skids.

Theres no visable interaction in the head, links etc so i was wondering what i may have done?!

A lifetime ago i remember i had a similar issue when i did the Eccpm mod on my rator which was down to one of the servos not having adequait throw or something of the like. On my FF9 that was easily sorted out but i hate to imagine how one would go about approaching this kind of issue using a DX7 :S

Any thoughts would be much appreciated.

Best regards

-Jvr
08-01-2007 Over year old.
 
 
RonHill
Veteran
Location: ..

1. Check to make sure all your servo arms are set correctly.
2. Check that all links from the swash up match on each side.
3. Make sure your end points match and that the servos move the same amount.

I had to re set mine up and a few things were off. It is much better now.
08-01-2007 Over year old.
 
 
kingair
Key Veteran
Location: Utah - USA

With a swash leveler you can check for interaction at the extreme ends of throw. If you don't have a swash leveler check out this post:

http://www.runryder.com/helicopter/p1297231/

This person explains how to level the swash and check for interaction with a pitch gauge. I found it to be a very interesting way for set up.

There is a very fine line between "hobby" and "mental illness."
08-01-2007 Over year old.
HOMEPAGE  
 
 
Chuckie
Key Veteran
Location: Crofton Maryland, MHA member

Just another perspective but if the heli is nose heavy you'll need back elevator trim to hold it level in a hover. Then when you go inverted you need to hold forward elevator in a hover and climbout due to the back elevator trim. You will need more forward elevator in a fast climbout.

How does the heli balance out?

Charles

Please stand by for faster service!
08-01-2007 Over year old.
 
 
SkateFreak
Key Veteran
Location: Cambs UK/Luton

Chucky, i think you bring up an interesting point there,
I do remember having to hold some back cyclic to hold a level inverted hover even after trimming...

I've just checked the balancing and it appears to be okay. Holding the heli by the rotor grips on it's side and rotating it about and seeing how it sits.
It'll happily stay where i leave it without pulling nose down :s

I'll have to look at the swash at +/- pitches i guess, it might have been windsheer causing the heli to pull back...

swashy swash time heh.

-Jvr
08-02-2007 Over year old.
 
 
Chuckie
Key Veteran
Location: Crofton Maryland, MHA member

Are you saying with the canopy on and no or half tank of fuel the heli is balanced? With equipment (rx, gyro, gov, reg, 2 cell lipo, etc) in the standard location in the radio tray the Pro is nose heavy.

You would hover inverted and climbout at full pitch on a day with no wind. Do this a few times to see the heli flys off in the same direction. Then land and change elevator or aileron end point a little to compensate, 5 to 10 points. Try a few more climbouts until you get the model to stay straight longer. Do this for upright climbouts as well. Now when doing big elevator flips or big rainbows the heli will fly straighter.

The problem with this is if you change the balance of the heli the compensation is now off. As you burn fuel the balance changes. Just don't go over board trying to get it perfect and learn how to compensate by flying the heli more.

Charles

Please stand by for faster service!
08-02-2007 Over year old.
 
 
j5coat
Veteran
Location: Phoenix

do as chuck says there and also use the SUBTRIM to level the swash at mid stick. if you do all that you should be really close to level all the way around.

Trex 700, Trex 600n
08-02-2007 Over year old.
 
 
Chuckie
Key Veteran
Location: Crofton Maryland, MHA member

I don't recommend using subtrim. The CCPM software works better if you don't use subtrim. It's better to mechanically change the links to level the swash if it's off.

Charles

Please stand by for faster service!
08-03-2007 Over year old.
 
 
1 page502 viewsPOST REPLY
Next D . Fast Lad Performance . Ace Hobby

.
.
Align T-REX 600N 700N > What did i do wrong? Interaction!?
 PRINT TOPIC Advertisers 

Subscribe to This Topic

Tuesday, December 2 - 1:26 am - Copyright © 2000 - 2008 runryder.com | email | link to rr | runryder needs cookie