Sunday morning started out great, perfect weather with a little breeze which would be perfect for some ZII flying! :D
Other than a couple of failed launches (one of which resulted in a torque roll and the ZII flying back into a hawthorne bush!) I had a couple of great flights with the ZII. See following video of one of these flights:
http://youtu.be/xjOIhRbDmT0 (http://youtu.be/xjOIhRbDmT0)
I'd calibrated the FY31AP during an earlier flight and on landing clicked the No4 dip switch down to save the stabilisation settings. On testing the stabilisation mode however the fun was about to begin as you'll see from the following video: :'(
http://youtu.be/r_sC9Nqtyls (http://youtu.be/r_sC9Nqtyls)
No problems with the take-off and having levelled out at a reasonable altitude my flying buddy activated the flight stabilisation mode setting for me. From the ground it looked like it was making little corrections, but from the flight video it was evident there was a fair amount of rocking up and down. Going into a turn, I started to lose altitude and pulled in a fair amount of up elevator to try and level out the ZII without much impact. She wasn't having any of it (from the flight video you'll see it was very unstable at this stage). By now from a LOS view point, I was worried about the ZII descending too much and going into a tree so with that disabled the flight stabilisation mode (ABM on the OSD). The result was that the ZII pitched up very violently and in doing so, ejected one of the flight lipo batteries from it's wing batterybay! The result was a very unstable ZII and the corn field below beckoned! Having recorded the OSD footage, this enabled us to pin-point the ZII within about 5 minutes. Luckily, other than losing one of the batteries and prop the ZII came off relatively unscathed other than a slight dent in one of the wings which shouldn't be too hard to sort out. The corn field must have softened the impact somewhat. Phew!
The only explanation is that the FY31AP must have been suffering from excess vibration, although this didn't show on the ground with motor test runs. Further testing before I try again I think, but having enjoyed some really smooth flights earlier in the day; I'm now questioning the use of the stabilisation function however the RTL is a major attraction however (not that I intend to fly too far away).
The first FPV flight will have to wait a little longer.
Bummer
havent flown my for a while as waiting for lipos
however when i tested mine stab mode, i too thought it was losing altitude, I want fpv so dont know if Mine was doing same as yours, going to be a bit more careful when im next out, thanks fornheads up
Glad to see you got it back ok. I see two things that stick out in that video.
First the ZII was not trimmed properly, it was gaining altitude all the time
Second was your artificial horizon showed no sign of the banked turn the plane was in. It should have been at the same angle of the horizon but wasn't.
What was a shame was the screen display choice, the horribly cluttered screen will show you your vibration reading so you know if that was it. But to me, your FY believed it was flying level when it was in a banked turn which lead to the rest
Cant watch it due to blocked music :) Might need to re-upload mate with a different sound track.
Like Coyote says.... turn up the OSD to full data and you will see a whole line of zeros very top left, these should stay zero all the time, if they start showing numbers at all then it means the FY is picking up vibration that is effecting it's sensors.
The oscillation is either your elevator gain is set too high on the FY adjustment potentiometer
or
looking at how the oscillation built up it would be handy to see a photo of how you have the FY mounted in the Z2, if its on the soft sprung mount then too high gain linked in with maybe the various servo wires connected to the FY starting to tug it out of level due to inertia as the oscillation starts would cause this.
PK
Top left not right AER0000
Thanks for the feedback guys. I will take your suggestions on board for future flights.
I'd run out of down trim on the elevator Coyote, hence why it was climbing slightly. I've now altered the elevator mechanically to allow more down. I have found that I've had to put in a fair bit of up elevator to get the thing away at launch. I'll check out the OSD, still learning what all the readings are.
PK, if you have a look on my blog http://mjc70.blogspot.co.uk/ (http://mjc70.blogspot.co.uk/) , you will see how the FY31AP is positioned. It's in the front battery bay behind the cameras and is mounted using some thickish double sided cushioned tape. It's not strictly on the CoG which maybe would also help too?
Quote from: mjc1970 on May 28, 2012, 11:09:05 PM
Thanks for the feedback guys. I will take your suggestions on board for future flights.
I'd run out of down trim on the elevator Coyote, hence why it was climbing slightly.
There is one of the pieces of the puzzle found. There is no point in setting up FY if the plane can not fly straight and true by itself. You must trim it so its perfect first before DIP 4 up and Stab on for >2 seconds. With the plane not being able to sustain level flight because its not got the throws it needs its constantly fighting itself and the wing and it can not win.
QuoteIt's in the front battery bay behind the cameras and is mounted using some thickish double sided cushioned tape. It's not strictly on the CoG which maybe would also help too?
And here is the second and third piece of the puzzle and prob the main reason of the problem.
Double sided cushioned tape is no good, I tried with velcro but although it works I still get readings on my X8, On my walker though I used double sides sticky pads, I stuck two together to double thickness and on my Walker I get 0000 all the time.
Also positioning the FY on the CG is highly recommended, although Gyro`s can be away from CG and work just the same, accelerometers are greatly affected by being away from the CG.
How far off the CG is the FY positioned Matt ?
Fix the issues above and I think you will have it sorted for the next flight
Oh I forgot to add, which is THE most important point.............
Your artificial horizon to me is the biggest issue, it did not show your plane banking at all. So stabilization settings don`t come into it untill that`s resolved, there is something very wrong there
Have you updated to 1.2 firmware ?
Yeah, I updated to firmware 1.20 yesterday morning prior to flying. The update was successful and I've confirmed it's at V1.20.
In the flight where we calibrated level flight, she appeared to be flying straight and level although we were doing judging it from a LOS perspective. Maybe doing it from a FPV perspective is better thinking about it.
Having just measured how far the FY31AP is from the CoG, I would say 3.5 inches forward of the CoG. Probably not ideal I know, but space issues don't really allow it to be positioned elsewhere.
Thanks again for the feedback.
No problem, always trying to help :)
Yes do it using the Hornet display, the altitude will show you if your sinking or climbing. Once its sits level you know you are trimmed true. LOS wise you really have no idea of climb / sink because depth perception looking up is pretty impossible. Take your video, the altitude always shows the plane climbing in RC and ABM mode ( because you ran out of trim )
If you cant get it any closer ( CG ) then you will just have to live with that.
After flying my X8 on it, I would recommend setting aileron and elevator gains to half as a good starting point as too not over correct on both axis ( assuming that you have enough but not far too much throws )
Thanks Coyote. We'll get there I'm sure! I'll keep you posted.
Cheers.
You can do the above and improve thing no end ( if the systems working ) but I am really concerned that your FY does not recognize the plane is turning, even if setup totally wrong, the artificial horizon should still show correctly even if it cant react properly
Ive watched again, you give trim during ABM mode, this does not work, because you plane can not level ( because of not enough endpoint ) you give it trim, you should not trim in ABM mode, if it cant hold in that mode then either - plane is not trimmed properly or not enough throws to let AP level it
But because your AP is showing it "believes" its level it wont be trying too, then when you feed trim in, because it believes its level it tries to flight your trim, the more trim you dial in the more it fights, hense its wobble gets worse and worse and worse
Another thing I noticed, your artificial horizon sometimes does not react to a banked turn, on my videos from the other week, mines not either ???? Sometimes iit does, sometimes its not
Back in the air and this time a 20 minute maiden FPV flight. Very pleased with the endurance. With two 4S 3300's, I still came back with 42% left in each battery pack. I wasn't really belting it however, I was just getting the feel of it flying around on 50% throttle. Here's a short clip with the highlights.
Ritewing Zephyr II ZII - Maiden FPV Flight - Leicestershire UK GoPro Hero 2 (http://www.youtube.com/watch?v=aFDGi0Arw2A#ws)
Still not convinced with the FY31AP/Hornet OSD. I'll upload an OSD video later for comment. The gains have been turned down on both elevator and aileron, gyro reset and flashed the firmware to 1.20 again, but I'm still nervy about trying it again!
Here's a video from the Hornet OSD. The artificial horizon seems very laggy to me and doesn't always show a true representation to the actual horizon. As can be seen from the AER reading, I'm not getting too much vibration. Given the slight fluctuations, do the values shown represent a potential issue?
Ritewing Zephyr II ZII - Maiden FPV Flight Hornet OSD View - Leicestershire UK (http://www.youtube.com/watch?v=pLBA63GhgLI#ws)
Coyote will reply better as he has this same kit (I have the earlier FY21AP etc) but I'd definitely be trimming the wing for hands of level flight and then doing the recalibrate dip switch thingy as that artificial horizon is a dead give away that something isn't calibrated correctly.
PK
Quote from: mjc1970 on June 12, 2012, 09:26:45 AM
Back in the air and this time a 20 minute maiden FPV flight.
Looking good Matt. I'm iching to get a nice FPV flight now.
Do you know what CoG I need to gain on mine?
Ta, Conners
There is something wrong still, its showing banked right turns when your level at times, then not reacting at all. I think a re-flash, then level calibrate first. Then set neutrals again and see how that is. Your values in AER are pretty low still, I presume your wires are slack too it.
When you boot up the FY does the FY31AP red LED keep flashing or go out ?
I've had another session with the ZII this evening and having backed the gains right down I think I'm about there with the FY31AP. Unlike previous flights where I was getting a lot of oscillating when feeding in elevator as I banked around, I was no longer getting that having back the elevator gain to a minimum. Applying ABM mode when taking the fingers off the sticks having applied either sharp aileron or elevator pretty well stabilised it. I say pretty well, as it was just going into a very slight dive. I landed and switched dip 4 back up to re-level it once again in the air. Having trimmed it out for level flying on just over 50% throttle, a then set the ABM switch to save the setting. Landed again, new batteries in but unfortunately on the next launch didn't get her away (no wind) and ended up ripping one of the side fins off (end of flying for today) and hence unable to test again! :-[
I feel a lot happier now though and fingers crossed I hope it's about there now. There was far too much gain previously. The artificial horizon seemed to behave a lot better too although I was concentrating on other things and didn't record the OSD footage this time.
Quote from: Coyote on June 13, 2012, 10:48:29 PM
There is something wrong still, its showing banked right turns when your level at times, then not reacting at all. I think a re-flash, then level calibrate first.
Then set neutrals again and see how that is. Your values in AER are pretty low still, I presume your wires are slack too it.
When you boot up the FY does the FY31AP red LED keep flashing or go out ?
That's good that the AER values are pretty low. The red LED light goes out when I boot up I believe, it's just the blue one which stays on.
Good to see its improved. I found with the X8 the other day I still had to trim via radio in ABM mode, it would slightly dive and turn to the left. I then trimmed the plane in ABM mode to get it to hold, once it was it was like flying on rails. This contradicted the rc level flight trim I had set, but when I came out of ABM it was still flying level ??? Work that one out hehe
Quote from: c0nners on June 13, 2012, 10:39:59 PM
Quote from: mjc1970 on June 12, 2012, 09:26:45 AM
Back in the air and this time a 20 minute maiden FPV flight.
Looking good Matt. I'm iching to get a nice FPV flight now.
Do you know what CoG I need to gain on mine?
Ta, Conners
My CoG is pretty well as the build instructions suggest. Can't recall what it is without referring to the instructions, I think 9 inches from the nose.
Good luck with your FPV flight. Great when you get them up there, but buggers to get them away! I have the Hacker A30 10XL V2 motor / X-55 SB Pro ESC combo and despite the ESC being set for a fast pickup, there is a second or so delay which is pain in the arse! Not sure if there is anyway around this other than changing the ESC for something else? I seem to recall reading on RC Groups others having similar issues with this same ESC.
Look forward to see some footage anyway Conners if you manage to record.
Quote from: Coyote on June 13, 2012, 11:45:43 PM
Good to see its improved. I found with the X8 the other day I still had to trim via radio in ABM mode, it would slightly dive and turn to the left. I then trimmed the plane in ABM mode to get it to hold, once it was it was like flying on rails. This contradicted the rc level flight trim I had set, but when I came out of ABM it was still flying level ??? Work that one out hehe
Bizarre! I didn't even think of trimming it in ABM mode! Having had another touch and go flight with it when ABM was engaged the other day, I was very close to ripping the thing out and listing on eBay or posting on the classified section on here! Fingers crossed I hope it should be fine now.
Cheers.
Here's a video from yesterday evening of further testing of the FY31AP in ABM mode on the ZII. Not oscillating this time thanks to backing the gains right down to next to nothing. Few more tweaks and I'll test the RTL. :o
http://youtu.be/XvSzCJBOyuU (http://youtu.be/XvSzCJBOyuU)
Nice 1 Matt, not bad at all :) Having your gains that low would suggest too much alieron travel ? I tuned my aileron gain using RTH first, if it snaked instead of holding straight at home I turned aileron gain down, once it stopped that was ailerons set
Maybe. The ailerons are set at 38% on the end points with 100 D/R and - 15% Expo on my Futaba 9C. Very little movement, but you don't need much and you can see from the video even at these settings how sensitive it is. I may dial in a little more expo.
I think it's getting there now though. Thanks for your feedback Coyote, it's appreciated.
Matt,,
Good to see the progress, nice flight mate.
Cheers,