Scary take offs on Align 3G

[sooren]

I am at the end of my tether with my 6003g LE nitro and need your help please guys.

First of all I could not get the GP780 gyro to behave - I could not dial out the tail wag - anyway got round this by fitting a spare GP750 and all is well.

Next problem is when I take off the heli leans to the left and sometimes comes back a bit. The only way to take off is to punch it into the air on take off. When it is airborne its ok but it is very scary to take off - Its like the sensitivity needs to be quicker so how do I make it take off level. Also in a hover it drifts to the left slightly and backwards - should I just trim this out, the 3G software has been updated to 2.1 - I am nervous of using the pots (they are both at 12 o'clock as per the manual) because one of the guys I fly with adjusted his today to the 1 o'clock position and his heli then had a terrible nod which he proceeded to crash on landing.

Thanks in advance
Regards
Paul

[Mslater]

Is your 3G sensor correctly mounted ?? Needs to be perpendicular to the shaft. You might also have the wrong tape but after your problems with the 780 I may possibly suggest bad vibes as the cause.

[sooren]

I will try a double pad on the sensor tommorow

[3d_willz]

i never knew you could still use a normal gyro on the 3g system mine had the gyro built in i never used a separate gyro.

[sooren]

The GP780 had have a lot of bad press so it was a 2 second job to put on a GP750 - Leave the original sensor/gyro , plug your tail servo into your new gyro (it will currently be plugged into the 3G unit - the one with the two pots), then the new gyro and gain lead into your receiver (take out the gyro gain wire and gyro wire out from the original gyro/sensor and then set up the new gyro.
I now have a nice solid tail.
Regards
Paul

[tourerjim]

You shouldn't really us any trim with 3G, sounds like to me as if your swash plates not level or you've got some sort of interaction, check that all your servo's are @ 90 degree & lower linkages are @ correct adjustment then be sure your swash is completely level.
To setup your tail @ 'delay' told tail stick 3/4 to your left hold that position then press set button to store setting.
Mine is very stable on lift off can take off nose-in.

[sooren]

You shouldn't really us any trim with 3G, sounds like to me as if your swash plates not level or you've got some sort of interaction, check that all your servo's are @ 90 degree & lower linkages are @ correct adjustment then be sure your swash is completely level.
To setup your tail @ 'delay' told tail stick 3/4 to your left hold that position then press set button to store setting.
Mine is very stable on lift off can take off nose-in.

I used a swash level tool, all arms at 90 degrees, no sub trim, never set my tail like that though. will try ans see if that makes a difference.
Because it pulls to the left on spool up I presumed it was the aileron sensitivityRegards
Paul.

[Made2Fade]

12 o clock is far too high, the recommended setting should be around the 11 0 clock mark for sports flying and a little less again for 3d. The GP780s are terrible and i stuck with my Quark/ds760s and bypassed it completely. Downfall is it uses slightly more power, ie your rx pack wont last as long. But then again if you use a 5000mah rx lipo like myself then thats not a problem
Paul id go through the 3g setup 1 more time as a matter of cause also (make sure pots are at 12 when ya do it then turn them down after the setup). Make sure everythings defaulted like pitch curves, no subtrim/trim, no expo/dr. Then you can put these back in and re-bind.

[Made2Fade]

Also one thing thats best to do is when ya turn your model on do it on a level surface if you can or better still take it to the flight line and start it there...

[tourerjim]

I used a swash level tool, all arms at 90 degrees, no sub trim, never set my tail like that though. will try ans see if that makes a difference.
Because it pulls to the left on spool up I presumed it was the aileron sensitivityRegards
Paul.

When you used the swash tool did you check to see if there was any swash interaction between max neg & max pitch! if you only set swash level on zero pitch you could be out on the collective end points.

[coolice]

Hi Paul.

Are you coming from a traditional flybarred model? If so a probable cause of a scary take off is because you are inputting cyclic corrections with the skid still in contact with the ground. What happens is you are commanding the heli to roll or pitch, the skids are not allowing the heli to move and so the 3G makes it move by adding more cyclic.
The same rule applies to pretty much all FBL models which is to not move the cyclic on take off, its difficult I know as it caught me out a few times initially. Having said this I can make small cyclic changes on take off on the larger (550+) size models, but keep them small.

Another thing is the eCCPM servos you've probably seen on the bench return to centre quite slowly if moved, if you wiggle the cyclic just before take off they might not have recentred properly yet.

Vibration on the nitro's is a big issue with FBL units, on my 3G'd 700N I found the Spartan mounting pad setup ideal. This was thick pad ~ metal plate ~ thin pad, with an Align velcro strap lightly over the top to steady the sensor from rocking in aggressive tic tocs.

I've not found you need to initialize the model on a level surface, its quite difficult out on the field to do so, but as normal do not move the model until you've seen the collective jump 3 times signalling all is set.

3G pot settings will change from model to model and depend on many factors, so start at the 50% mark and adjust as necessary for your individual model and this is advised in the manual to.
I have found though on all my models that the elevator pot tracks about 10% lower gain than the aileron, which I think is due to the boom length/weight of the tail hung out the back providing added mass once the model is flipping.

Definetly to start with take off on as level a surface as possible, with time you'll get used to the 3G and what libertys you can take making cyclic adjustments on take off without giving yourself a scare.

The tail wag you're seeing is most probably due to the heading lock gain on the tail being too high, out the box at 70% its too high for most tail servos. Some are ok but with the Aligns I've had to go down to 45-50% which has stopped the slow almost gain like wag, but no matter how low you put the gain its still there.

Definetly look at mounting pad method and also where is the sensor mounted on your model?
.

[Made2Fade]

3G pot settings will change from model to model and depend on many factors, so start at the 50% mark and adjust as necessary for your individual model and this is advised in the manual to.
I have found though on all my models that the elevator pot tracks about 10% lower gain than the aileron, which I think is due to the boom length/weight of the tail hung out the back providing added mass once the model is flipping.

FWIW Paul this will also depend on how far out you are on the cyclic servo arms. The further out you are the less gain will be needed. Works just like a tail gyro and mechanical gain achieved by lengthening the tail blades or going out on the tail servo arm. Same concept. If your on the newer align servo arms with the 2 sets of holes and your mounted closer to the centre then you will find you will need more gain. So im guessing you are? and this is why your up in the 12 o clock mark and not the 10:30 - 11 oclock mark on the 3g gain pots.
The concept of taking off on a level ground... think about your tail when your in heading hold and you have to find that point to keep the tail straight before you take off. Same things happening but on 2 axsis on your cyclics!

[Made2Fade]

Oh watch Bert Kammeres videos on his setup and youll find exactly where he is on the pots Note which servo wheels hes using and how far out/in the balls are.

[serpent887]

3G is of the few fbl gyros that accept trim, so feel free to use it once airborne.
Also, look at your ail/ele gains in 2.1, they may need lifting a few points to achieve a stable lock.



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