450 3GX setup on Align 450 DFC Pro...

[ALIGN_BOY_UK]

I have successfully flown and setup a couple of 450 sized Blade heli's and having made good progress I thought I would treat myself to an Align 450.

I brought a kit and built the heli without an issue - was really pleased with the discrete storing of all the cables, especially when i needed to use an additional receiver as a result of owning a DX6i...the carbon frame is beautifully on show!

Anyway, the mechanical setup went well and I have a level swash plate, +10 / -10 degrees pitch and all servo's have been 90'd...with a little help from the sub trim. Wasnt sure whether to use that or swash mix. Thoughts?

The issue now is that having followed the videos on here, the swash plate moves as required during testing and returns to level when released. When I add in throttle and try to lift off, the heli insists on tipping to the right and when I manage to settle the heli, the swash plate seems to be moving slowly back to the centre position.

I have a green light and a red light on the 3GX as no GOV on 6 channel. The rudder moves in the right direction and responds to tail movement. My Gyro on the DX6i is set to about 75% - not managed to check it properly for 'hunting' yet as cant get off the ground!

Any help would be appreciated.

Thanks.

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...I am running 3GX version 3.1 by the way. Thanks in advance.

 

[murankar]

Okay first did you do the sub trim in the radio or 3gx?

Also are you on 3.1 or 4.0?

4.0 has a tail issue and 3.1 hates being on the ground for long periods of time. Basically you need to get just enough head speed to get it off the ground asap. Then it will be solid in the air.

As for all the other stuff the 3gx gurus will have to j help.

Sent from my LG-E980 using Forum Runner

 

[Slobberdog]

I have successfully flown and setup a couple of 450 sized Blade heli's and having made good progress I thought I would treat myself to an Align 450.

I brought a kit and built the heli without an issue - was really pleased with the discrete storing of all the cables, especially when i needed to use an additional receiver as a result of owning a DX6i...the carbon frame is beautifully on show!

Anyway, the mechanical setup went well and I have a level swash plate, +10 / -10 degrees pitch and all servo's have been 90'd...with a little help from the sub trim. Wasnt sure whether to use that or swash mix. Thoughts?

The issue now is that having followed the videos on here, the swash plate moves as required during testing and returns to level when released. When I add in throttle and try to lift off, the heli insists on tipping to the right and when I manage to settle the heli, the swash plate seems to be moving slowly back to the centre position.

I have a green light and a red light on the 3GX as no GOV on 6 channel. The rudder moves in the right direction and responds to tail movement. My Gyro on the DX6i is set to about 75% - not managed to check it properly for 'hunting' yet as cant get off the ground!

Any help would be appreciated.

Thanks.

- - - Updated - - -

...I am running 3GX version 3.1 by the way. Thanks in advance.

My first question is how you got +-10 degrees pitch, did you use swash mix or travel adjust

 

[ALIGN_BOY_UK]

To set the swash, I started with a brand new profile on the DX6i. Set it to heli, 120 CCPM and ensured the throttle and pitch curves were 0, 25, 50, 75 and 100.

I then put the 3GX in to DIR mode to centre the servos and bypass the gyro.

I then adjusted the servo horns as close as I could to 90 degrees, before tweeking with sub trim.

When happy, I removed the head and used a swash leveller, adjusting the lower links from the servo to the swash to ensure the swash was level.

I then checks the tail servo was at 90, adjusting the tail push rod to ensure the angle of the pitch slider was at 90 degrees to the boom.

I attached the blades, still at mid stick and then adjusted the links from the swash to the blades to reach 0 degrees.

Full throttle and had +10 and then no throttle to achieve -10.

Swash moves in the correct directions as does the rudder.

In DIR mode the swash is perfectly level, but when you start the whole system in normal mode, getting a green gyro light and red GOV light, the pitch servo is slightly higher, thus its going right.

I have tried adjusting trim at this point, but both AIL and PIT servos move.

Does this process highlight any errors?

Murankar, I am nervous to rush the heli in to the air as I suspect it is more than an unhappy ground behavior...which is exactly what I get witb the 130x - a known issue.

Any other thoughts?

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...oh forgot to say ive never used travel adjust?!

 

[Slobberdog]

You can't use trim with the 3gx it does not like it, I inhibit my trims on all my heli's so I can't inadvertently use it,

What values do you have in swash mix, and just double check what values you have for travel adjust on ail, ele, and pitch

I can't see anything else in your write up that could cause it to act screwy, do you have any tight wires going into the 3gx or do you have them secured just before the gyro,

 

[ALIGN_BOY_UK]

Just to clarify, the sub trims either side of the sticks are all centered, I am referring to the sub trim in the menu - should I not be touching either of them?

Can you explain what I may use travel adjust for as I have never touched the settings?

The swash values are +70, +70 and -50, which were produced when trying to reach the +/- blade pitch.

Another possible issue - when testing a new heli I always use training pads to protect against tipping...could this be throwing the 3GX?

All the wires are fed nicely through the heli frame, although there are a couple of tight cable ties?!

Thanks for everything so far.

 

[Lee]

Using training gear can cause problems. If you have to use them, try to make the arms as short as you are comfortable with.
This will reduce problems with the FBL.
Try not to make the cable ties too tight. Cover the part of the tie pressing against the cables with a piece of shrink tube.
This stops the tie cutting through the cables over time.

 

[murankar]

All i know about 3gx is what i stated earlier. 3.1 has a bad habit of tipping while on the ground, ask Derek he knows about this all to well.

I also know that 4.0 is not nearly as good as 3.1 due to the tail holding issues with fast hard tail stops. This issues will surface while doing pyros and stopping it hard.

Keep with 3.1 and learn to get it off the ground. While you spool up you will have a slow start. While its in this phase start feeding in collective till it gets off the ground. Once in the hold a hover till the head speed gets to full rpm.


I also know that once you turn off dir mode the swash will be lethargic to inputs. Its just because its on the bench and not in the air. While in dir mode the swash should act as normal since your by passing the gyro.

Sent from my LG-E980 using Forum Runner

 

[Tony]

I have to correct this thread. You MUST use subtrim to center the servos on teh 3GX. There is no setting in the gyro to do this like there is on the AR7200BX and the Ikon. Your setup was spot on the way you had it. If you have changed anything, return it to where you had it.

The tipping to the right is a major issue with 3.1. It HATES to sit on the ground and will tip every time. The ONLY way you can stop this is to get it in the air BEFORE you spool it all the way up. You do this by starting with a sitting heli with a good ESC with slow start. Raise the throttle to about 60% immediately and let it spool up about half way. The head speed will still be low, but then pop the collective stick to about 75% to pop the helicopter in the air. Once in the air, it should be pretty solid if your setups are close to mine.

I HIGHLY suggest that you update to 4.0 to get the helicopter in the air. You may or may not have a tail issue, but at least you can get your cyclic setup. The tail is solid in the air, but if and when you move the tail, it may or may not kick back to where you started. I'm working to see if there is a fix to this. But I suggest going to 4.0 to get a feel for the helicopter. After that, you can go back to 3.1 and pop it into the air as explained above.

Hope this helps.

 

[ALIGN_BOY_UK]

Just a quick thank you to all those who replied.

I visited the hobby shop i got it from today and he kindly got it flying for me.

It was a combination of missing something in the 3GX setup and my pitch curve.

All flying now and what an awesome bird!

Thanks again.

 

[Tony]

Hey, all that matters is that you got it flying! Now get us some video of this heli in the air!!!