General 450 Pro 3GX V2 Still cant get it in the air!!!!!

[Graham Lawrie]

Getting up to half stick now and it spins very fast anticlockwise?

 

[zenmetsu]

If it is spinning counter-clockwise, then the tail is not producing enough thrust to offset the torque from the main rotor.

I have zero experience with flybarless setups, so I'll let the pros hand this. Usually this means that either your mechanical setup is way off or the gyro gain needs to be increased. Mechanical setup means that the tail should be close to flat pitch when the servo is neutral, or have a little positive pitch. Positive pitch in this case where left = up, right = down. If that makes sense.

 

[Graham Lawrie]

Yup makes sense to me i am just going to put a video of it on as soon as i have loaded it onto youtube.

 

[heli-maniac]

sounds like the gyro is set to reverse

 

[Graham Lawrie]

How do i tell if it is reversed?

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http://youtu.be/ALwuZNKxVf4
Did like stoke said and took both rotors off this was the result??

 

[zenmetsu]

Easiest way to tell if it is reversed, I came up with this one

1. Rotate tail grips so that they are near vertical.
2. Fold the tail blade on top either forwards or backwards until it is folded 90 degrees.
3. Power up transmitter, ensure zero throttle stick.
4. Connect battery on heli.
5. Top tail blade should be roughly parallel to the boom. If not, rotate the whole heli clockwise/anticlockwise until it is parallel to the boom.
6. Once parallel, rotating the helicopter should cause the top tail blade to "point" at the original heading... in other words, it will rotate the opposite direction.

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I guess that I really should make a video of this technique, it will be more clear.

 

[Lee]

Easier way. Have the heli pointing away from you. With one finger, push the tail to one side. The front edge of the tail blades should turn to point towards your finger.

 

[stokke]

Well I watched your video, and the swash seems to stay level during spool up. This would indicate that there is some issue with the main blade set-up (I'm not talking about the tail going the wrong way now, but the bird tilting to the left). Since we know the swash stays level, we also know there is no problem with the electronics.

Therefore I think you might have a tracking issue - one blade is on another pitch than the other. E.g. when one blade i at 0° - the other is maybe +2° or whatever. Worth checking.

 

[zenmetsu]

Ahh Lee, that is a good one. I found that folding the blades will make it easier to see small blade pitch changes. Out of curiosity, are FBL systems AVCS or Rate mode? Can you adjust this from transmitter, say, to go between rate and heading hold for the tail? Don't mean to derail the thread, just curious.

 

[Graham Lawrie]

Video would ge good

 

[zenmetsu]

...Since we know the swash stays level, we also know there is no problem with the electronics.

Therefore I think you might have a tracking issue - one blade is on another pitch than the other. E.g. when one blade i at 0° - the other is maybe +2° or whatever. Worth checking.

For what it is worth, the one photo he posted of "mid-stick" conditions shows one blade that clearly has a negative pitch. Swash may be level, but the linkages in the head may need tweaking.

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For clarification, the first post has 9 photos. Image 5 of 9 shows a blade that is close to level, maybe slightly positive pitch. Image 7 of 9 shows a blade that has negative pitch.

 

[coolgabsi]

Yep that's why I was wondering about his gyro correction directions. Mid stick is mid stick. And of what zenmetsu says is confirmed by graham , then that'll just cause tracking issue not tipping issue ..


And Stokke: with 3gx unlike the beastx I think the Tx needs to be on swash 120degrees .. That means ccpm mixing for a dx6i ...

Graham: yeah after you check the swash directions AND the gyro directions take off the blade and spin it up and hopefully make a video

Fly safe!! have fun!

 

[stokke]

Mid stick is mid stick. And of what zenmetsu says is confirmed by graham , then that'll just cause tracking issue not tipping issue ..

I recall a similar case from a previous post where I called out the same diagnosis, fellow RC-helpers doubted this being the reason then too - in the end, I was correct after all

And Stokke: with 3gx unlike the beastx I think the Tx needs to be on swash 120degrees .. That means ccpm mixing for a dx6i...

On my Tx (the DX7S), I have a menu called "mixing" - this is the settings I was referring to (I have 3GX on my 450 as well remember). When addressing the "CCPM mixing" - it was the "mixing" menu I was referring to (didn't remember exactly what it's called ATM).

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And yeah, I still think you should check your tracking Graham.

 

[heli-maniac]

go in to the tail set up again go through to the last step that is the reversing spot if the light is on red then move the rudder stick left or right and turn it green if is green same thing change it from what it is and give it a try other thing is if the servo is reversed in the tx will make a do this all so

 

[Tony]

Okay, 34 posts and I don't have the time to read all of them. So here are my questions.

Are you SURE you are at 0º pitch at mid stick?

Do you have a pitch gauge? If not, then there is no way to know you have no pitch.

If you do have a pitch gauge, what is your full positive and negative pitch reading?

Heli spinning around really fast, your gyro is reversed. In the 3GX you need to go into the program and reverse it.

 

[john2012]

sounds to me if it want's to turn over see if your swash settings are set for 120 and no other

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if you haven't got a pitch gage then do you have a protractor you can make you pitch gage from a piece of paper

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also you may want to check the meausurements of your ball links and see if they are the same all of them form the swash up center to center make sure there the same on both sides

 

[breeze400]

Okay, 34 posts and I don't have the time to read all of them. So here are my questions.

Are you SURE you are at 0º pitch at mid stick?

Do you have a pitch gauge? If not, then there is no way to know you have no pitch.

If you do have a pitch gauge, what is your full positive and negative pitch reading?

Heli spinning around really fast, your gyro is reversed. In the 3GX you need to go into the program and reverse it.

That's what my feeling was nit enough pitch to lift off!

 

[Graham Lawrie]

Okay, 34 posts and I don't have the time to read all of them. So here are my questions.

Are you SURE you are at 0º pitch at mid stick?

Do you have a pitch gauge? If not, then there is no way to know you have no pitch.

If you do have a pitch gauge, what is your full positive and negative pitch reading?

Heli spinning around really fast, your gyro is reversed. In the 3GX you need to go into the program and reverse it.

Hi Tony, yes i have the guage and followed your video + and - 12 degrees. Mid stick on TX checked and visually it looks zero to me. I will however check again. I put my TX settings the same as in your video, identical, and it performed the best so far, but never took off and wanted to spin anticlockwise at the tail. I have posted videos and took both rotor blades off. Also spun her up with tail rotor blades only on, and it stayed in the same place, and no vibration issues?

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go in to the tail set up again go through to the last step that is the reversing spot if the light is on red then move the rudder stick left or right and turn it green if is green same thing change it from what it is and give it a try other thing is if the servo is reversed in the tx will make a do this all so

With Tonys DX6i settings, at power up i have a green and red light,when i switch gyro on both turn red.

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For what it is worth, the one photo he posted of "mid-stick" conditions shows one blade that clearly has a negative pitch. Swash may be level, but the linkages in the head may need tweaking.

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For clarification, the first post has 9 photos. Image 5 of 9 shows a blade that is close to level, maybe slightly positive pitch. Image 7 of 9 shows a blade that has negative pitch.

Hi Zenmestu, sorry for that, my bad photography they are the same blade,just different angles, though i am going to check pitch and length of rods.

 

[heli-maniac]

if im thinking right you have the 3gx mounted on the top were the anti rotation bracket and if so both lights should be green rate mod and one should go red in head holding mode
and i would reverse the rudder in the tx

 

[Graham Lawrie]

if im thinking right you have the 3gx mounted on the top were the anti rotation bracket and if so both lights should be green rate mod and one should go red in head holding mode
and i would reverse the rudder in the tx

Yup 3gx on top, 1 green and 1 red at start up, i flip gyro switch on and both turn red. Settings are as Tonys video of DX6i. Charged my batteries and spooled up, tried reversing rudder and it turned the other way , clockwise. I will try spooling up tomorrow after work,after i check pitch again. I will do a video from switching on to spooling up. Many thanks Graham