3gx help.. Really

[crash-test-tomo]

Morning folks. I was asked to have a look over and do a complete setup on a trex 700 a friend has just bought.. Just to make it that little bit extra fun the heli has a 3gx on it! My friend is relatively new to flybarless helis so has no real plan to change this until he has a little more experience.
Good news is going through the dir menu, setup went well. All directions, travel, sensor directions etc seem to be now perfect!
The problem we are having, which may be down to the 3gx itself? Is that when giving even the tiniest rudder input the servo moves very quickly to its limit as if we had given a full speed full throw rudder input. Almost as if the servo is on the wrong frequency? I have looked through the align manual which isnt the clearest and YouTube videos for the tail portion arent as useful, any pointers would be awesome guys..

[exiged]

Ill not sure if the wrong servo frequency would effect servo speed. Hows the mechanical set up? How far is the ball from the servo centre?

[atomiccomp]

That's fairly normal behaviour from a 3GX, it's because as you feed input in the helicopter isn't moving- so it adds more until its full deflection because it's trying to move the helicopter left or right.
Which software version is the 3GX runing? If its V5 to setup the tail perfectly run it in rate mode and mechanically trim the tail so it's not wandering in the hover, re-set your end points, chuck it in HH mode and your good to go.

I rate the 3GX, loads of folk slate it however I found it to be an good controller.

[Grumpy]

Yeah, as last post, it's normal behaviour (for any HH tail gyro) when tested with the heli on the ground. How fast the servo moves over is largely dictated by how much tail gain you have set.

[crash-test-tomo]

Ill not sure if the wrong servo frequency would effect servo speed. Hows the mechanical set up? How far is the ball from the servo centre?

Me either tbh, im not familiar with the system at all so we spent some time scratching our heads lol
I didnt actually measure ball to centre but it doesnt look too long/short at all, whoever built it id say was fairly competent as all servos were at almost perfect 90 etc from the get go

[crash-test-tomo]

That's fairly normal behaviour from a 3GX, it's because as you feed input in the helicopter isn't moving- so it adds more until its full deflection because it's trying to move the helicopter left or right.
Which software version is the 3GX runing? If its V5 to setup the tail perfectly run it in rate mode and mechanically trim the tail so it's not wandering in the hover, re-set your end points, chuck it in HH mode and your good to go.

I rate the 3GX, loads of folk slate it however I found it to be an good controller.

Great, thats along the lines of what I was hoping! I just told him not to fly it until someone who knows the system had confirmed or denied.
Im not sure on software version, I couldnt check as no cables were supplied with the heli.
I did mention we may need to do a rate mode flight to set propper centre so thus will be out first job tomorrow afternoon once esc/governor is set up!

I have heard the 3gx slated alot too but for my friends level of flying it should still feel a million times better than what hes used to.. Hopefully the led menus etc are simple enough to.follow for tuning

[atomiccomp]

Great, thats along the lines of what I was hoping! I just told him not to fly it until someone who knows the system had confirmed or denied.
Im not sure on software version, I couldnt check as no cables were supplied with the heli.
I did mention we may need to do a rate mode flight to set propper centre so thus will be out first job tomorrow afternoon once esc/governor is set up!

I have heard the 3gx slated alot too but for my friends level of flying it should still feel a million times better than what hes used to.. Hopefully the led menus etc are simple enough to.follow for tuning

If I recall the 3GX uses a standard mini usb lead for the software to connect to a PC. You can download the software from Align's website.
If its setup with a standard setup he should find it fairly easy to fly.

[coolice]

Hey Buddy.

The problem you are seeing is as mentioned already, normal as the gyros are rate demand in all the FBL units and so alter a control surface and wait for the models fuselage to respond and if it doesn't the FBL unit adds more. This is why it's advisable not to input cyclic commands while the models skids are still in contact with the ground, but small inputs I've found not to be a problem.

Yes correct, a rate mode setup of the tail pushrod length is advised with the 3GX, so once it's back in HH mode it works at it's optimum.

Another note is to make sure the Rx power supply is up to scratch with the 3GX and Gpro in fact, steer clear of the Align regulator and if fitted replace before flight I'd say to be safe.

Any questions fire away, spent a lot of time with the Align FBL units.

Ian Contessa

[crash-test-tomo]

If I recall the 3GX uses a standard mini usb lead for the software to connect to a PC. You can download the software from Align's website.
If its setup with a standard setup he should find it fairly easy to fly.

Thats perfect. I dont remember seeing one at all tbh but I didnt really look as he said he didnt have one.. I do have brain and miniV cables myself so hopefully one will be the same fit

[crash-test-tomo]

Hey Buddy.

The problem you are seeing is as mentioned already, normal as the gyros are rate demand in all the FBL units and so alter a control surface and wait for the models fuselage to respond and if it doesn't the FBL unit adds more. This is why it's advisable not to input cyclic commands while the models skids are still in contact with the ground, but small inputs I've found not to be a problem.

Yes correct, a rate mode setup of the tail pushrod length is advised with the 3GX, so once it's back in HH mode it works at it's optimum.

Another note is to make sure the Rx power supply is up to scratch with the 3GX and Gpro in fact, steer clear of the Align regulator and if fitted replace before flight I'd say to be safe.

Any questions fire away, spent a lot of time with the Align FBL units.

Ian Contessa

Thats awesome Ian, thank you. I did suspect it would be something along these lines!
It is pretty much a stock combo heli as far as I can see so it may well be the align regulator fitted, is it sort of medium esc sized and in a clearish heatshrink/rubber sleeve? Iv not seen him fly for quite some time but from what he says its very light sport flying at most, should the align reg still hold up? Or is it more of a likely to fail completely scenario? Powering it he has a 2s reciever pack.

Hate to ask a stupid question now but I never really owned a propper flybarred heli and brain doesnt need it.. how do I get it into rate mode? Is this something in the transmitter or a 3gx setting?
Would I also be right that if any flip/roll or piro rates are too fast or slow we can setup the tx's dual rates or should this be done in the 3gx aswel?

Cheers guys

[crash-test-tomo]

Did a quick search, he is using an ALIGN RCE-B6X 6 AMP VOLTAGE REGULATOR BEC?

[electricsceadu]

with my experience with the 3gx
I would throw it in the bin before it throws a wobbly and crashes the model
great when it works but when it decides it's had enough you are a passenger in a fall from a great height

[Grumpy]

Did a quick search, he is using an ALIGN RCE-B6X 6 AMP VOLTAGE REGULATOR BEC?

Get that thing in the bin. They were ok for flybar helis and analogue servos but not up to the job with digital servos and FBL. You can just power the servos direct with a 2S LiFe battery, or get something like a Castle BEC Pro HV BEC that works off the main flight packs and save a bit of weight.

[coolice]

Thats awesome Ian, thank you. I did suspect it would be something along these lines!
It is pretty much a stock combo heli as far as I can see so it may well be the align regulator fitted, is it sort of medium esc sized and in a clearish heatshrink/rubber sleeve? Iv not seen him fly for quite some time but from what he says its very light sport flying at most, should the align reg still hold up? Or is it more of a likely to fail completely scenario? Powering it he has a 2s reciever pack.

Hate to ask a stupid question now but I never really owned a propper flybarred heli and brain doesnt need it.. how do I get it into rate mode? Is this something in the transmitter or a 3gx setting?
Would I also be right that if any flip/roll or piro rates are too fast or slow we can setup the tx's dual rates or should this be done in the 3gx aswel?

Cheers guys

Did a quick search, he is using an ALIGN RCE-B6X 6 AMP VOLTAGE REGULATOR BEC?

Morning mate.

No problem, you're welcome.

Ah ha, yes that's the regulator. I was right to ask then as this would have been supplied with the kit.
Replace it, even if it supplies the rated 6amps it's still not enough really. 10 amps continuous is ideal, so that puts a CC BEC PRO in the list or as above a good old LiFe Rx pack which when charged outputs 6.6 volts so works great with any servo.
If you go the LiFe route create a wiring harness that provides at least two servo plug style power connections to the 3GX. Reason being servo plugs are only rated to 5 amps max, so like the CC BEC PRO if we have two going to the Rx/FBL unit we provide the 10amps capability :-)

The Align reg also wasn't known for its mechanical reliability to, so this makes it even easier to advise replacing it.

Yes correct, rate mode you will switch to via the gyro gain switch on the Tx which is usually channel 7 (aux2) from memory with the 3GX.
Positive travel values on this channel set the HH modes gain value and negative values set the gain value in rate mode.
You'll see on top when in either mode as the LED is Green for HH mode and red for rate mode if I recall correctly.
Always power up the 3GX and let it initialise in HH mode though and then switch into rate mode, or else some funny things can happen.

Ian

[crash-test-tomo]

Always power up the 3GX and let it initialise in HH mode though and then switch into rate mode, or else some funny things can happen.

Haha, funny things sounds promising!
Thats awesome Ian thank you. I have advised he gets the reg off there and goes with, as Steve said too, something like the cc bec pro.

Threw some settings in the radio tonight and the good news is.. It flies!
Got the tail set in rate mode somewhere near as he only has one flight pack. The only other thing I picked up was that it feels like maybe the cyclic gain is too high. Im going to take a couple of my own packs next time to make an attempt at getting it dialed in, which I guess will be a learning curve for both of us!!

My friend was buzzing like he'd munched a dozen disco biscuits to finally get it flying! Took me back a couple of years seeing someone so excited about flying!
Hes coming from an mcpx and blade 450 3d so id say most of what he knew about helis has just changed lol