Photohigher skyline rsgs


pixvertex

Member
denny i don't have any clue why you have that much trouble. And it is not that worse on my side.
It is not a plug and play solution for sure. Perhaps you expected too much.
It is hobby for me right now. And from making a mk by hand optimize, do it again and so forth i really did expected this to work from the beginning.
Spend 20k or more and it will work.
Still they are on it. And it is getting better every time from them and the community ! This is what counts.
My 2 cents ;)

Thank you chris for your findings !
 
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nicwilke

Active Member
The idea that has transformed the performance is shown in the picture. All this crap about wiring is not going to help much. Two things have made this work. One is the mounting of the imu and the other is the damper on the tray arm. I did explain why it has to be this way. When I say work I mean work at the top level. The point that you probably missed is the fact that the AV200 has the imu on the same end as the servo pulley which makes it much more rigid and could be the reason why some are not having so much trouble. The camera tray bends with the weight of a heavy camera on the AV130 and this produces a wind up. If you cant get your tilt gain to hold 255 without an oscillation it aint gona work.

How about testing some bracing under the tray if you think there if torsion is the problem? I'm not bothering as I'm only using an NEX-5n.

I believe my setup is currently at 85% now.


Sent from my GT-I9300 using Tapatalk 2
 

I tried mounting the IMU on soft pads like you, but the stiffness of the wires touching the side of the frame (av200) move the IMU and affected performance. I expect this is similar to frame bending on the av130.

The latest av200 has a very rigid tray, probably 3 times thicker than the old model.



The idea that has transformed the performance is shown in the picture. All this crap about wiring is not going to help much. Two things have made this work. One is the mounting of the imu and the other is the damper on the tray arm. I did explain why it has to be this way. When I say work I mean work at the top level. The point that you probably missed is the fact that the AV200 has the imu on the same end as the servo pulley which makes it much more rigid and could be the reason why some are not having so much trouble. The camera tray bends with the weight of a heavy camera on the AV130 and this produces a wind up. If you cant get your tilt gain to hold 255 without an oscillation it aint gona work.
 

nicwilke

Active Member
Just trying to be helpful by sharing what works for me without being too offensive. I dont get jitter with tilt gain of over 500, so don't think I will bother with the Tonka toy solution.
Chris, thanks for the solutions you're offering, very helpful.....
 

I found two tiny little rotary dampers after I shredded my little LED book reading light. This thing has been sitting in my bedside drawer for so many years and every now and then I press the little button and watch in amazement as it smoothly opens. :nevreness:

I'll try and find a way to attach one of them to the tilt mech and report back some time soon. If only my 3D printer had been ordered earlier.
They feel "just right". Wish I had a little torque meter to find out their resistance to rotation.

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DennyR

Active Member
Just trying to be helpful by sharing what works for me without being too offensive. I dont get jitter with tilt gain of over 500, so don't think I will bother with the Tonka toy solution.

500 on a AV130 with a heavy camera - This I would like to see, As they say when the flag drops........

I guess it's time to start showing some mirror tests and some flight videos. When facts are few bull**** abounds.

I now have this working not far short of the Zen. lets see what you have. And what the others have, then we can make the true evaluations that can be of benefit to the world.

All I said was I would make this work with what ever it takes to correct design mistakes that I did not make. I inferred that the main problem is mechanical feedback errors and not electrical so lets see who is right shall we. I will have a video up by next week I expect you to do the same.

The AV 200 is less of a problem and the AV130 is a tougher assignment because the IMU is on the same side as the motor. If I were to make a design change on the tilt drive it would have an 8.4 volt high res servo running in direct drive with the imu on that same shaft. I have tested the imu on the bench in a controlled environment (rate table) and it does not have any of the jitter problems or pointing inaccuracy.

This is a bit like GoPro they sit back and let the customers do the clever bit.
 
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Digitech

Member
hang on your using a 730 to cover the mishaps?
this is like going back 2 years ago...
i am using this el cheapo gyro from china fro 125 buck that does a good job stabilising on 3 axes...
for now we are getting great results with the standard DJI 5.12A firmware a Av-200.
and the sony 730
however for quality the sony is crap , it has a poor image.
i have some of my customers using a Naza to do the stabilisation.
 

DennyR

Active Member
I tried mounting the IMU on soft pads like you, but the stiffness of the wires touching the side of the frame (av200) move the IMU and affected performance. I expect this is similar to frame bending on the av130.

The latest av200 has a very rigid tray, probably 3 times thicker than the old model.

I think you just proved a point, I dont have a AV200 to test but for sure it is a better design because of the tray rigidity and the position of the IMU. Frame bending is a function of feedback overshoot oscillation. not the same as pulling the IMU with the wires.

I did say that the mounting of the IMU should be done with the wires trapped down to same base. The thichness of the rubber mounts needs to be a little less than what I originally showed. Is it really a requirement to have this? Yes because when you introduce motor vibration into the tray assembly it will be seen by the imu. when you crank up the gain settings. To get something that resembles the accuracy of the Zen you need high gain and you need to remove some movements that are introduced by free play in the roll cage. That took three Tonkatoy mods. The RSGS is capable of the required resolution, it does not get the chance to perform on a standard AV130. I would now be happy to use a RSGS on a mount of my own design.
 
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We are currently running Heli Gyro anti vibe tape like you find on ebay as it was a lot less prone to having the IMU flex away from its base. We also strapped all the wires down, but a little slack obviously needs to be left to allow for rotation against the roll frame. I'm sure you worked that out too.

When are we going to see some "in the mirror" from your Gimbal?

I think you just proved a point, I dont have a AV200 to test but for sure it is a better design because of the tray rigidity and the position of the IMU.

I did say that the mounting of the IMU should be done with the wires trapped down to same base. The thichness of the rubber mounts needs to be a little less than what I originally showed. Is it really a requirement to have this? Yes because when you introduce motor vibration into the tray assembly it will be seen by the imu. when you crank up the gain settings. To get something that resembles the accuracy of the Zen you need high gain and you need to remove some movements that are introduced by free play in the roll cage. The RSGS is capable of the required resolution, it does not get the chance to perform on a standard AV130.
 
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jappie911

Member
Can someone please send me 1.1.7 ? Over pm first.

I think I am going to use it for a shoot in a few hours..

I did some shoots with 1.1.3 with VERY low gains, working quiet good.. but today there is a bit more wind, so maybe I can benefit of 1.1.7 with a bit higher gains..

But have to update setup in the next 1,5 hours.. so if anyone wants to share ? Please pm.
 

jappie911

Member
Sorry for being so impatient... (hate to do that.. :dejection:) but can someone please sent it ?

Thanks in advance !

EDIT !! : GOT IT ! RO is going to send it to me !

Thanks RO ! (lld)
 
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Three separate power supplies?

Actually I have 4 power distinct power supplies.
1. 6V via a Bec for the Airframe RX, the DJI WKM and the pan servo,
2. A 6v eneloop pack to power a RX for the Skyline and the skyline itself
3. A 6V eneloop pack to power the Tilt servo
4. A 6V eneloop pack to power the Roll Servo.

All these power sources whether BEC or battery MUST have a common ground (0v) If not you will get ground loop issues.

All the Y lead loom arrangement does is ensure that the power supplies are kept separate, whilst having a common signal connection and common ground. You just need to literally plug 3 Y leads together and snip both the red wires in the first Y lead so that no power gets from the Skyline to the servos, also the servos do not get any power fluctuation from each other.

I think that it is about time to replace the RSGS loom and all the other wiring with a PCB to tidy things up. SOrry my diagram is not clear, when we have got clear of all our Olympic visitors I will make a video.

I am pleased with what I have got now but YMMV.

Chris: Thanks for this explanation. One last question, and only because you mention this battery pack: When someone says 'independent' or 'separate' power source does this mean that a separate BECs that are all working off of the same primary lipo do not qualify? Is this why you mention the battery pack so that it is truly separate or would separate BECs be alright and constitute separate power sources? When I first read about the H-loom it said that it would provide separate power to the RSGS and power going to the TWO servos. Based upon this I bought Two BECs. Now it sounds like I will need three unless of course I must use a battery pack as you suggested. If you would please clarify this for me and also tell me if you still feel that this action is necessary. Thanks.
 

aknauer

Member
I have been testing the 1.1.7. It appears that usable gain settings are only achievable when the power supplies are split several ways to the Skyline and Servos. For testing purposes this is OK to trouble shoot – however that can’t be the final solution since nobody wants to add batteries or BECs to this extend. It is counter-productive in terms of weight and expense. Already the wiring is quite messy and difficult to route neatly without interfering with the inputs to the Skyline. Has anybody considered the use of flat-ribbon cable to connect the Skyline to a breakout-box further downstream where it could be mounted in a better place?

I have tried the felt washer solution and that seems to work OK, although I think it is generally defeating the purpose of fine response in the axis. Removing slack in the gears of the servos by grease filling is probably the better way since it will not introduce as much friction. However it is a method one can’t expect to be followed to overcome design issues with the Skyline.

I also found that there is noticeably less jitter when I remove all inputs from the RX. I had only Tilt Input connected lately since Roll Input is not a priority. Sub-Trim and Trim on the channel do not change this behavior. The Plus Pins are not connected.

At least with the AV130 I also suspect the 360° shaft connection to be a source of feedback, since there seems to be a certain amount of flex in the connecting plates for the shaft. When I lift the copter by its arms I get oscillations at much lower gains then when lifting it by the gimbal assembly/landing gear. The mass of the whole assembly seems to amplify the oscillations – which makes sense. The only solution I see here is a re-enforcement of the plates holding the shaft.

The last test flight gave almost usable results. Since I had to use small gain values on nick and roll to prevent oscillation – which by the way could make the copter uncontrollable if they happened while airborne and found their way into the FC, there was too much lag in both axis. On Tilt it was more acceptable with Roll leaning to the direction of the turn and recovering when straight and level.
 

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