General Trex 450 pro dfc Maiden flight!!........well almost =/

[transpro61181]

Attempted a maiden hover today but it has an issue where the swash wants to start tilting to the left pretty hard (viewed from the rear... tail facing me) before i even attempt to make it light on the skids causing the heli to want to pitch left drastically almost causing a blade strike. (with training gear on!!) both the pots on the 3gx are set at the 12:00, i also tried 2:00 position with the same issue. Everything has been set on this heli VERBATIM to Tony's 3gx setup guide. The swash has been leveled perfect with a swash tool. The swash correction directions are all correct according to Tony's videos. Any recommendations?

 

[murankar]

If it is 3.1 then you will want to lift off the ground before you reach full head speed. If its 4.0 not sure what to tell you.

 

[transpro61181]

 

[transpro61181]

Well its definately at full headspeed way before it gets light on the skids. I am running 3.1 and my throttle curve is at 0 40 75 75 75 and Im pretty sure it starts to get light on the skids at around 75 percent collective (because of that heavy training gear). Do you recommend a linear throttle curve? Thanks for the help!!

 

[murankar]

The throttle curve is what I use, or close to it. Pitch curve for normal could be like something similar to 45 47 50 75 100. If that does not work then Tony may have to chime in. Try a lower head speed like 0 40 65 65 65.

This problem is inherent with 3.1. Once in the air I hear it's great.

Sent from my LG-E980 using Forum Runner

 

[Tony]

This is a double edged sword. The training gear will help for situations like this, however it also transfers more vibration back to the gyro. Try to update to 4.0 and see if that helps with the tilting. 3.1 is great in the air, but fat lot of good that will do if you can't get it off the ground...

 

[transpro61181]

Well got an update. I believe i have a blade balance/tracking issue because the heli has a pretty bad vibration. when i remove the main blades the swash stays level the entire time on the ground with the training gear.
Here are some videos...shot these videos with the heli firmly held in one hand and camera in the other.



Oh yeah almost forgot...the inherent risk of such risky behavior...haha.....

 

[Slobberdog]

How tight are your blades, if they are slightly to tight they can't straighten out easily and can cause a fair bit of vibration as a result.

 

[transpro61181]

the blades fall to a 45deg angle when held sideways

- - - Updated - - -

just put a set of spare blades on it and seemed to get rid of some vibration but still same issue with swash..think im about to go back to 4.0...... had 4.0 on it before and the servos liked to twitch every 45 secs so went back to 3.1 hopefully the servos wont twitch in flight

 

[transpro61181]

I want to try 4.0 but did not because I read a lot of posts about tail issues...the tail is rock solid on 3.1 so dont want to create additional issues, additionally so many people are happy with 3.1. I am 95 percent convinced that this is not a setup or firmware issue and vibration is causing issues with this gyro. I also read that these 3gx gyros are stupid sensitive to any small resonance vibration unlike the more expensive beastx ones that are resistant to vibration interference...guess u get what u pay for..im gonna try to mount this gyro down below and if that dont fix it im completely lost ...so burned out trying to figure this out....gonna go visit family for a week and come back to it with a fresh mind...

 

[Slobberdog]

Have you balanced and cog'd you main blades,

 

[transpro61181]

I have not but I have tried two different sets of blades with the exact same effect on the swash which leads me to believe that the blades "might" not be the issue. but when i get back a week later i will check blade balance according to "Bob White's blade balancing 101"

 

[transpro61181]

Well back at it again...installed 4.0 per Tony's recommendation and still the same swash tilt to the left issue. I did a little test, I set the heli down with it on not spooled up and started tapping on the gyro rapidly with my finger and low and behold...started tilting to the left again. I have done everything I possibly can to eliminate as much vibration as possible. It has slight resonance vibration on spool up that goes away once head speed increases. The gyro is mounted as shown in the videos with the original double sided tape supplied with it and the gyro is not sitting up against the plastic at all....I even rerouted my wires so there would be more slack in them as I heard if they are too tight it can transfer vibration to it. I am about to go to the store and use some different double sided tape....if it continues to do this then I have no clue what to do next.

 

[Graham Lawrie]

I had a similar issue with mine and it turned out to be a small nick in the servo wire I have a video of it in the 450 section I also had the pitch set by eye, which when I got a digital pitch gauge, I found I was miles out.

Brave man holding a heli that close could end in disaster blades and heads do come loose