GoPro rudder wobble

[alistair watt]

Hi guys /girls
I have a slight wobble on the tail of my new 550 Dominator with g pro.. I have tried the rear tail slider for stiffness but its loose. I have been setting the gyro on the menu of GPro software up and down by 5% and have settled at 80 which is beginners GPro setting, but I still get a slight wobble right to left. So not sure what it could be? It hovers well other than the little wobble which is a bit annoying really as I don't have that problem in any of my other trex helis with flybarless.


Any ideas please.
Thanks
Al

[bloom691]

Hi,

I have a 500L with GPRO and I tried moving the gain up and down without effect. It behaved just like you described. Then someone suggested I move the rudder push-rod further OUT by one notch on the servo horn (so making it more responsive). That seemed to fix it for me

[alistair watt]

Thank you Bloom for the reply..
It is in the furthest hole on the arm as it is... I have moved the Gpro gain to 83 which seems to have made it better very slightly. Tonight I am going to take the tail end to bits to see if the bearings are in the correct way round.. My only other option is to reduce the I and P gain in the Gpro take them down a couple of steps to see if that sorts the wobble out.

Will be the weekend before I can flight test as not home till dark.. Thanks again for your suggestion
al

[TR450ZS]

Alistair, what are your ESC settings? If you have enabled the governor, and the gov gain is not right then you will get the tail problem exactly as described.
The correct way to approach this, assuming that all mechanical causes are ruled out, is to run the a non gov throttle curve first.
Then set the tail up in Rate Mode and hover the heli to make sure it does not rotate around it's axis. Adjust the tail control rod length to get this right. Then go back to heading hold setting.
Then do a few flights and dial the tail gains in to as close to perfect as possible.
Once you know for sure your tail is right then you can enable the gov function on the ESC.
Either way, even if you are not using the gov, the GPRO likes the tail to be set up first in Rate Mode to get the neutral pitch spot on.

[TR450ZS]

I forgot to mention, once you have a solid tail and you go back and enable the gov in the Castle, if you then suddenly get tail wags again , then reduce the gov gain 1 click at a time until the wag goes away. The gov with incorrect gain setting will cause the headspead to "hunt", and this will confuse the tail into wagging.
Many people have chased tail wag in the fbl unit when in fact the gov gain is the culprit.
Also, go back and reset the GPRO to it's default settings when you redo this setup, it should basically fly pretty well straight out the box. All mine did, and I have 4 helis on GPRO. You can fine tune once you get the feel of the heli.
Also, move the tail servo horn ball distance to that which is stated in the manual. Having the horn length too long will cause unstable tail, and give you more throw than you need to prevent binding. Reducing the throw then in the software to prevent binding means that the servo only has a very short throw to work with AND be precise, with very little resolution.
PS. I see in your other threads you do have the GOV enabled, and I am now pretty sure this is where your woes are originating. Disable it for now, you can go back and enable it once the tail is solid.

[alistair watt]

Thank you TR450ZS for the reply that was good of you..
I know the servo arm is in the last hole so I could move it in to the second last hole which is where the Align manual suggests.

I don't have govenor mode set up in the Tallon 90 if I remember, but will check that when I get home as its many weeks since I set it.
I will try also your suggestion of setting in rate mode..
Will let you know but will be weekend before I can get over to the club

Much appreciate the help
al

[TR450ZS]

Ok Al, I'm sure we can get this heli sorted. If you like, you can post your castle settings file here, or email it to me to have a look through it as well.
cheers
Allan

[alistair watt]

Allan thanks very much. I will let you know the settings when I can get a chance to look at the Heli after work... Do you suggest the rudder in the second hole in from the end?
Thanks again much appreciated
al

[alistair watt]

Setting for talon 90 helicopter
Fixed end points medium 5. 5
Gov mode. Simple
Auto rotation enabled. Medium 5
Gov gain low 15. Spool rate medium. Head speed High. 8

Brake disabled
Brake delay 6 sec intermediate Ramp
Cut offs auto Lipo. 9.0 auto Lipo volts 3.2
Voltage cut off. Soft cut off
Current limiting normal. Current cut off. Soft cut off
Motor start 100 high. Motor timing Normal 5 direction reverse own. 12 kHz
Power off bleep enabled. Link live disabled. BEC 6.0v
Hope this helps
Al

[TR450ZS]

Originally Posted by alistair watt

Setting for talon 90 helicopter
Fixed end points medium 5. 5
Gov mode. Simple
Auto rotation enabled. Medium 5
Gov gain low 15. Spool rate medium. Head speed High. 8

Brake disabled
Brake delay 6 sec intermediate Ramp
Cut offs auto Lipo. 9.0 auto Lipo volts 3.2
Voltage cut off. Soft cut off
Current limiting normal. Current cut off. Soft cut off
Motor start 100 high. Motor timing Normal 5 direction reverse own. 12 kHz
Power off bleep enabled. Link live disabled. BEC 6.0v
Hope this helps
Al

Al, if you have it set to fixed end points then something else is wrong on your setup, either in fbl or mechanically on the heli.
One thing you need to change on your ESC settings is that Current Limiting setting. Change it to insensitive, its OK to do so on a Heli and much safer too. The normal setting is more for aeroplane mode. With a heli you want it on insensitive, otherwise you may find that heli dropping out of the sky one day in a brief hard manoeuvre.

Back to your problem, first off, set the tail servo horn length as per the manual, (assuming this heli is all stock?).
Set the GPRO to all default settings for 550 size heli.
Then disconnect the tail push rod from the tail pitch slider, and make sure that moving the pitch lever by hand it is butter smooth in both directions, all the way to the end.

What headspeed are you running where you encounter the tail wobble?

[alistair watt]

Sorry I don't know what the head speed is .. Really its just on hovering above mid stick 1 to 5 deg I guess..
I will reset the normal as you suggest and also check again the smoothness of the tail slider....
Thanks again I am sure it will fly well once I set it as you suggest...
Thank you will let you know this weekend
al

[alistair watt]

Went to field having changed to inner hole. Set the cut off to insensitive. Put update in talon software. It flew rubbish including the talon playing up. Came home re programmed Talon 90. Tried to sort out the wobble by up and down on the gyro gain. Then tried I and p gain by 5 numbers and heli spun into a crash. I have lost faith in the GPro All the guys at the field bought the Spartan and they all flew with no trouble at all. This G pro has cost me blades and possibly the main mast although it does not seem bent. I was lucky...I may just have to bucket the Align GPro as has Align as they now are not selling it in their new kits. buy. Spartan 1 might be the solution
I just don't know what else to try. Thanks again for the help. May rebuild the tail end in case it's stiff.
Al

[nabl74]

Firstly im sorry about your problems so far. I went through the same thing chasing tail wag and at the time didn't know too much.

You need to approach your rebuild systematically to ensure you don't end up with vibes again.

I posted recently regarding tail wag and vibration analysis not too long ago. Have a read of that and good luck

If your heli has spun uncontrollably, this is very unlikely related to the gpro . A faulty gyro can cause this, but from reading the thread and your description of issues, it seems more reasonable to believe the issue was mechanical.

Tail binding, thrust bearings binding under full speed rotation ( may not be evident during hand checks on bench) or even faulty servo , loose tail hub coming loose, incorrect tail pitch and leaving in rate mode, incorrect gyro initialisation tail control rod coming loose from tail ball link, etc could all be reasons for the tail spinning out of control. You didn't mention whether you found any obvious reasons for tail spin or whether you tried to diagnose for any mech issues after spin.


It's very possible that even with an alternative gyro, if the mechanical issues remain after your rebuild then you will still have tail wag.

One other thing it's been my experience that most negativity of the gpro you read online is based on poor mechanical setup. I've been flying the gpro on both my helis for the last year and whilst most guys at club fly vbar brain or spartan, ive been able to get my helis both locked in. Most guys dont believe it when they see how my heli flies and then find out im running gpro.

The gpro does work well. Align are offering beast x as a strategy to beef their sales by providing consumer choice. I dont believe they have abandoned it.

Good luck my friend

Here is my post
https://www.helifreak.com/showthread.php?t=720866

[alistair watt]

Nab
Thank you so much for the reply its very helpful...
I have changed the blades main and tail to new ones Also balanced the blades last night..
Funnily enough I had started a complete mechanical check of everything thus, tail is free and smooth ball link not a problem... redone all wiring to gpro as suspected could be loose connection or pulling the unit----but not.

Late last night I reset the pinion gear to make sure it was as per manual.. It was slightly up, so perhaps this may have caused vibration.. It was too late to check last night..
I fired it up before that without blades on... As I throttled up to past middle stick when I moved the rudder stick to the right or left that is when i get the jitter on the slider which is the problem... The heli was on the bed so it was on a soft platform - so should not have been any vibration as it was damped..

I have really gone as far as I can ,I only hope the pinion being not level with the gear may be the issue ... If not then it must be Gpro.
One strange thing was as I throttled back to zero then slowly pushed the stick up the talon did not seem to respond so I will have to check the setting on the talon 90 again... I am very very sure they were as per the Align Gpro setting other than reverse and insensitive?

Much appreciated I will let you know...
al

[alistair watt]

Balanced new blades reset pinion tail as smooth as anything. - tail wobble tonight really bad. GPro on the way back to shop. Sad
Al

[alistair watt]

Well at long last the shop posted a new replacement Alig Gpro. Unit to me.......its been quite a wait.. I set it all up again on the software, but the Heli mechanically has not been touched

...I flew it in my back garden a few monents ago........stable as anything. If I were to be really picky a very very slight vibration on tail but I bet it can be dialled out as its all standard Align factory software settings at moment. ..am going to field to give it a proper test later. So it seems to have been an. Align GPro faulty unit.. Or perhaps a very over sensitive sensor on the unit


Al

[nabl74]

Great news!!!!!
Enjoy your new bird!

[alistair watt]

Thank you but its still a Horror story. Went to club only to find the Gpro had lost bind.. So back home... I decided to start again from the beginning setting up swash and Gpro as per Jeff Fastbinder s video.. I just could not get both sats to bind only one.. So again in the back garden took it for a flight.. Slight tail wobble and not as good as yesterday, but Ok
took it inside checked to see if motor etc would spin up a little.. But sadly motor just would not activate...although one sat showed a bind and every thing was working except motor...Then it came back...So tried again and this time no response fro motor.. It was like I had throttle hold on....Suggests speed controller not speaking to Gpro... I am just really fed up with this Align product...Its cost me blades lots of time and a long wait for another unit... I look at Colin Bell and Jeff and can not understand why they get it to work and I seem to be from a different planet... So its getting near a hammer job modification I just don't know why it won't bind two sats and lose initialisation after one flight......

I just re did a complete set up Bind. etc and it won't go to the next stage of arming the motor even checked Talon 90 software.. The motor won't arm the green light is on and all other servos work. Al

[nabl74]

No experience with spectrum on gpro. Using futaba myself. With futaba i run a seperate receiver so not reliant on gpro for receiving.

That said im sure others here have a gpro working on spectrum. Perhaps someone here can help?

Do you have a heli club near you. Hands on experience always helps

[alistair watt]

Thank you Nab174
Unfortunately nobody at my club went Gpro (Spartan or Beast) So sadly on my own here, however, last night late as I was looking for my Hammer I had a thought. I checked the end points that were set up as per the Gpro software correctly...But thought perhaps the Talon 90 needs a different set of end points... Late last night I boosted up the end points low and high one or two clicks. and the motor registered by a nice tune...So without blades on it worked...Still does not solve the second Sat not accepting a bind or why it lost bind at the field? I also not sure why the settings would have been all that different from the original Gpro.

So need to do a flight test at the weekend I hope.

Its a shame that Align and Castle (as it came in an Align Combo kit ) did not go the extra bit and write a set of instuctions for mortals like me to follow instead of having to rely on Utube videos that although good their stuff always seems to work first time.
It seems a shame that companies don't do their videos with a proper crew instead of doing it themselves, don't get me wrong I appreciate the effort these guys make to help us out...But it always seems that they are showing things off screen instead of cutting to a close up of item as you would if you put some production value in it.. I certainy would have paid for a download or DVD if it was properly shot and would save me hours of searching the web... All I want is a step by step guide as to how to set a combo up... Is that askng too much?
But I must say I do appreciate all who try to help doing Utube set up build videos so please don't stop.
al