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Author Topic: My Alien H4 680mm Build inc probs & crash vids! - Now with NAZA...  (Read 24769 times)

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Offline PaulJC

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Well, i've posted a few bits here and there about my build but thought i'd collate it all in one place where i can add to it later on...

Specs:
Alien H4 680 folding frame.
Emax 4008 380Kv Motors.
Emax 30A SimonK ESCs.
APM 2.5 with with NEO8M GPS, Telemetry and MinimOSD.
9 Channel OrangeRX with 2 satellites.
Carbon 15x55 Propellers.
6S 10000mah 40C Turnigy battery packs (used on my heli's), these are heavy and will be probably be replaced at a later date i can almost have 16000mah for the same weight...

I also have GoPro Hero 3 Black, Tarot T2 Gimbal and ImmersionRC Vtx to be fitted, i want to put a bit more time on the airframe first though...







The build and setup went pretty well, i did have a problem with getting her level which you can read about HERE

Today the wind died down a little so it was officially maiden day :) Of course this was never going to go smoothly and my telemetry modules decided to pack up working... :banghead: this aside all went fairly well, still pretty windy and gusty out there but not as bad as the past few days have been...

1st small flight was in the back garden, just enough to pop her in to the hover and get her trimmed out using 'Save Trim' on the APM, still pretty windy so this will probably need redoing another day...

Then it was time to pack the car and head to the field, once at the field and on the same packs i powered up, mindful to leave her sat on the ground for 5 minutes while it got GPS fix as i had no telemetry to tell me when i had a decent HDOP figure, i then lifted her up in to a hover, selected 'Altitude Hold' and she held pretty well given the conditions, then in to 'Position Hold' which again worked well given the conditions and the fact no tuning had taken place, she oscillated a bit and fought against the gusts but she was reasonable, so now back to 'Altitude Hold' and to run 'Autotune' this done it's dance all over the field, battling wind as it went with me chasing it back to a decent position several times, no sooner had it finished that the lipo alarm went off and she came down with a pack voltage of 22.3 (3.7v per cell) perfect :)





I gave her a minute to cool down then threw on another set of packs, the plan this time was to see how long she would run for, the voltage of packs when fitted was 25.0v, when she came down they were 20.0v! A bit lower than i would like! However this was 31:30 later!!! My lipo alarm started beeping for 3.6v on the lowest cell at 28:30 but i decided to leave it up in the air until RTL failsafe kicked in at 21.0v, by the time i got the packs home and back on the charger they had bounced back to 21v so they are charging now to see how many mah they take back in...

Now these packs are not light, they are used in my helis and weigh in at about 1.7Kg for their pair!! Multistar 12000mah weigh in at about 200g less and would guarantee me 30 minutes of flight time without hitting failsafe. potentially their 16000mah packs would see me in the air for 45ish minutes depending on how it handled the 200g weight penalty, these flight times are without gimbal/fpv gear so it's a test that will be repeated at a later date...

I then threw on my last pair of packs and just had a jolly around the sky, it will definitely need to be retuned in better weather, it handles well going slowly but any kind of speeds and the transitions back into hovering are very sloppy, no telemetry/fpv OSD so no idea how fast/high she went but not much of either this time out... All in all not a bad maiden, highlighted a few bits that need doing/changing but more for robustness and reliability than necessity...


Jobs that need doing urgently:

Really only getting the telemetry back up and running.


Changes that need to be made:

Something to aid orientation - thinking LED's  :-/

Improved/more robust landing gear - It works, but it's flimsy, a good knock would see it broken off and camera/gimbal/props buried in the dirt, i need to start looking round for a replacement/alternative...

Battery mounting - I currently have 5000mah packs, so thats 2 packs per flight, i have tried them side-by-side and vertically stacked, side by side is far from great, keeps the CofG high up though, vertically stacked was better but obviously carried the weight further out from roll center, also my velcro straps are elasticated, i need to source some decent LONG straps to hold the batteries in place, maybe this will also be dealt with along with the landing gear problem who knows...

I also have some new smaller ESC's running BLHeli but i'm in no rush to fit them and i have an additional 4 motors so potentially an X8 in the future but again it's fine as it is for now :D







So, anyone know of any robust, rigid landing gear that will mount a 60mm spaced gimbal and carry 10000mah of 6S batteries?!
« Last Edit: June 03, 2015, 00:55:17 by PaulJC »



Offline PaulJC

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Re: My Alien H4 680mm Build - 30 Minute+ flight on maiden day...
« Reply #1 on: May 07, 2015, 22:03:25 »
Well, i've just ordered these to give them a go, only £17 from the UK, i've already got Tarot brackets for 10mm tube fitted along the bottom of my Quad so these should fit on nicely...


Offline bigadg

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Re: My Alien H4 680mm Build - 30 Minute+ flight on maiden day...
« Reply #2 on: May 07, 2015, 22:06:57 »
Where did you get them from Paul
stu
F450 Spider,APM 2.6 Flight controller,Ublox NEO GPS
APM Power Module with BEC,HP2212 920KV.
Quatro ESC.4S 5200 mAh Lipo. Turnigy 9x Transmitter

Offline Nige8021

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Offline PaulJC

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Re: My Alien H4 680mm Build - 30 Minute+ flight on maiden day...
« Reply #4 on: May 07, 2015, 22:35:59 »
http://www.ebay.co.uk/itm/281464101412?_trksid=p2060353.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

Yup, exactly there ;)

Well, looks like i may have overdone it coming down at 22.0v lol, to be fair this pack was charged up to voltage by 9000 mah but the rest was spent getting them in balance... Future time limit set at 25 minutes... Not bad for 10000mah, whenever hobbyking pull their finger out and get packs in stock i'll probably go 12000 or 16000mah anyway...


Offline Nige8021

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Re: My Alien H4 680mm Build - 30 Minute+ flight on maiden day...
« Reply #5 on: May 07, 2015, 22:44:30 »
I'm hoping they're a bit stronger than the previous ones I had?? as after one uncommanded landing phase, one of the legs where it clips onto the rails split !!   

Offline PaulJC

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Re: My Alien H4 680mm Build - 30 Minute+ flight on maiden day...
« Reply #6 on: May 07, 2015, 22:47:01 »
I'm hoping they're a bit stronger than the previous ones I had?? as after one uncommanded landing phase, one of the legs where it clips onto the rails split !!

Noted, i will keep an eye out for that if (when) i have any bumps...

Offline nub

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Re: My Alien H4 680mm Build - 30 Minute+ flight on maiden day...
« Reply #7 on: May 07, 2015, 22:57:17 »
30+ minutes of flight time, hope you did more than hover aboot ;)

looks pretty :cool: a nice clean build.
Point and click.

Monkey see, Monkey do.

Offline PaulJC

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Re: My Alien H4 680mm Build - 30 Minute+ flight on maiden day...
« Reply #8 on: May 07, 2015, 23:02:29 »
30+ minutes of flight time, hope you did more than hover aboot ;)

looks pretty :cool: a nice clean build.

Nope, hovered for all of it.. (Well actually stuck it in 'position hold' and had a drink and a smoke... lol)

Hovering is the least efficient way to fly, no transitional lift ;) So in theory flying it about it may have lasted longer.....  :o

Offline PaulJC

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Re: My Alien H4 680mm Build - 30 Minute+ flight on maiden day...
« Reply #9 on: May 07, 2015, 23:19:44 »
Just found some velcro battery straps that are perfect length, 420mm, as used on a Gaui helicopter  :laugh:


Offline PaulJC

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Re: My Alien H4 680mm Build - 30 Minute+ flight on maiden day...
« Reply #10 on: May 08, 2015, 11:13:40 »
Plugged in the APM this morning to see what PIDS autotune had come up with, and they are all standard, so i can only assume i brought it down to early or they didn't save so i'll redo this next time out...

Hover throttle percentage is only 38% so there is plenty of scope for the gimbal/gopro and possibly larger battery weight, what is the max throttle % recommended for an AP ship? It needs scope to climb out easily in an emergency but i'm not going to be doing any monster full throttle climbouts any time soon so performance in that respect isn't an issue....

I also pulled the logs to see if anything untoward was going on and they seemed fine to my limited knowledge, highest height reached LOS was 116m, orientation was almost impossible but it was in position hold and just went up and back down 'just to see' quite nicely and without any drama :)


Offline PaulJC

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Telemetry is fixed...
« Reply #11 on: May 08, 2015, 12:11:54 »
Well today i needed to get the telemetry up and running, it's a luxury i don't want to live without...

First things first i needed an FTDI cable so i could attach the 'air side' module to my computer to see what settings it had on board, i know i've got a couple of them somewhere, you think i could find them though?!?! Bugger... :banghead:

Luckily an Arduino Uno board can be rigged up to perform the same function, i soldered an adapter together for the radio module and breadboarded the connection to the Uno and we were connected  :smiley:



I had read that Mission Planner may have a glitch in it when it comes to transferring any changes from the ground module to air so i downloaded the 3DR Radio Config tool, connected to the air module and pulled up the settings to find it didn't really have any, that'd explain it!! How it happened i don't know...



So i flashed the latest firmware, reset the settings to default and saved them to the module, it now looks much better  :smiley:



Just to make sure i done the same to the ground module, powered them both up and they connected straight away, Telemetry problem solved  :smiley: :smiley: :smiley: ~~

Offline PaulJC

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Re: My Alien H4 680mm Build - 30 Minute+ flight on maiden day...
« Reply #12 on: May 08, 2015, 15:52:56 »
So i'm now sat waiting for the arrival of parts, hate that, but once the undercarriage arrives and the new battery straps get here i'll put it back in the air and re perform 'autotune' then it'll be time to fix the gimbal/camera gear etc, with that in mind i thought i'd do a mock setup to make sure everything works as i have new VTx/VRx etc...

Connect VRx to an old LCD i used to use for FPV, all powers up fine :)

Connect GoPro direct to VTx and picture appears on the screen, lovely...

Now connect MinimOSD in-line and get an onscreen display... Could this really be that easy?!?! Ahhh but wait, no Mavlink Data  :huh So i fire up Mission Planner and connect the telemetry and i start receiving 'Heartbeats', Awesome  ~~ But, no data with them, all values are on zero or not changing...  :banghead:



I've had this board without a firmware update for quite some time so i guess that'll probably be a good place to start and then off to google to see what i can find... Anyone experienced this before?

Offline hoverfly

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Re: My Alien H4 680mm Build - 30 Minute+ flight on maiden day...
« Reply #13 on: May 08, 2015, 18:42:40 »
Data is not automatically sent you have to request it(grovel to 3dr) The settings are on this page.

https://code.google.com/p/arducam-osd/wiki/Troubleshooting

Drove me nuts getting it right,but oh the pleasure when the data flows. :sweating:
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Re: My Alien H4 680mm Build - 30 Minute+ flight on maiden day...
« Reply #14 on: May 08, 2015, 20:07:09 »
I've already tried changing those settings and no joy, i think it's the firmware tbh and trying to flash it with an Arduino still is not exactly a robust link, FTDI cable is on order and i think i'll put this to one side for now and come back to it another day before i smash it to bits  :wack0 :banghead: :wack0 :banghead: :wack0

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Re: My Alien H4 680mm Build - 30 Minute+ flight on maiden day...
« Reply #15 on: May 09, 2015, 09:35:36 »
If the A.P.M. is sending data the led on the osd board will be flashing , try pressing the reset button. If that fails remove all sharp objects from workshop and go walkies.
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Offline PaulJC

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Re: My Alien H4 680mm Build - 30 Minute+ flight on maiden day...
« Reply #16 on: May 09, 2015, 10:39:17 »
If the A.P.M. is sending data the led on the osd board will be flashing , try pressing the reset button. If that fails remove all sharp objects from workshop and go walkies.

Thats ultimately what i ended up doing... Stepping away that is...  :wack0 :wack0

Offline PaulJC

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Re: My Alien H4 680mm Build - 30 Minute+ flight on maiden day...
« Reply #17 on: May 09, 2015, 11:39:23 »
I might be getting somewhere... The OSD works! :)

Today's workflow so far:

Unsoldered bridges on OSD...
Powered 5v and 12v sides separate (measured at 4.74v and 11.45v)...
Flashed Firmware 'MinimOSD Extra Copter 2.2'...
Flashed Firmware 'Character_Updater_FW'...
Updated Charset 'MinimOSD_2.4.0.2.mcm'...
Flashed Firmware 'MinimOSD_Extra_Copter_R800.hex'...
Went through 'Config', 'Panel 1' & 'Panel 2' saving all to OSD...
Removed 12v Power...
Disconnect from FTDI...
Resoldered Bridges...
Reconnect to APM...
OSD displays but still showing all zeros.....
Connect APM to MP via telemetry radios, no change...
Initial Setup > Optional Hardware > OSD > Enable Telemetry... Still no change...
Change cable for OSD only (Tx>Rx & Rx>Tx)...
OSD working working woop woop  :notworthy:
Change cable back to the one with Telemetry... :crossfingers:
All zeros again...  :banghead: :banghead: :banghead: :banghead: :banghead:
Unplug telemetry module... No Mavlink Data...  :thumbdown: :thumbdown:

So the OSD works, just not at the same time as telemetry  :banghead: :banghead:
The thing that is baffling me is it's obviously receiving Mavlink data, just not displaying/interpreting it when the Telemetry is attached in anyway, being connected to Mission Planner seems to make no difference...

I have tried changing settings as given about, tried all sorts, now at a bit of a loss, seems like i can have one or the other...  :cry :cry :cry




Offline PaulJC

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Re: My Alien H4 680mm Build - 30 Minute+ flight on maiden day...
« Reply #18 on: May 09, 2015, 15:09:31 »
I give up... I have spent the best part of yesterday and 5-6 hours today flashing and reflashing and rewiring and trying different combinations and getting nowhere...

There is now a thread for my MinimOSD drama HERE

I've also posted over on DIY drones as thats a pretty heavy APM orientated forum to see if anyone there knows what the hell is going on, i need a drink...

Offline PaulJC

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Re: My Alien H4 680mm Build - 30 Minute+ flight on maiden day...
« Reply #19 on: May 09, 2015, 17:25:16 »
Thanks to 'Jimmer' i now have a working OSD!!! Woop woop  :cool: :cool:

He suggested to me on the thread where i asked for help that it may be a power issue, so i've soldered some headers into the breakout for the serial port, connected it all back together and it works just fine  :o

It would appear that the MinimOSD needs a healthy power supply to function and that some little wires shared with the Telemetry radio are just not good enough to supply both!

I had to split the frames and take a fair amount of my quad apart to achieve it so i'm going to leave it that way now until i have all the final bits to finish it off, i'm waiting on the undercarriage and also have some LED's on their way from Hobbyking...

Once thats all sorted it'll be autotune (again) and gimbal tuning then i'll be able to start using her from some aerial video/photos as planned and also FPV :)

Although i keep seeing all these little 250 Racers, for £150 it might be hard to say no to one of them lol

Offline PaulJC

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Re: My Alien H4 680mm Build - 30 Minute+ flight on maiden day...
« Reply #20 on: May 11, 2015, 14:37:05 »
Bit more progress today, new battery straps and undercarriage arrived, i wanted the U/C set a bit wider front to back than the design planned so i cut the foam in half and just put it either side.

I also always had the plan of having my gimbal extended out the front to clear the props so already had purchased some 1m long carbon tubes, i can now mess around and find the perfect distance before chopping them down, the gimbal is a tarot T2 but now running on an Alexmos 32Bit controller which will allow for future upgrades if i wish... (Different Gimbal/Camera or 3rd Axis addition)...

Just waiting on some LED strips i've ordered that should be here tomorrow then she can go back together again :)


Offline PaulJC

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Re: My Alien H4 680mm Build - 30 Minute+ flight on maiden day...
« Reply #21 on: May 13, 2015, 12:20:55 »
Well she's all back together today, OSD and telemetry all working as required, FPV, Gimbal and GoPro fitted, LED's fitted and an AUW of 2350g without battery packs, i'm using a 3S 2200mah to power the VTx, LED's, Gimbal & to charge the GoPro (current draw is 1.5A ish for this lot) it weighs 185g, I'm still going to be using 2 x 6S 5000mah packs as flight packs which weigh in at 1665g for the pair, this gives me a total flying weight of 4200g, initially i'll just pop up a quick hover in the garden to work out current throttle % etc, hopefully in an hour or two's time, then maybe later if the wind stays calm i'll be able to get out and rerun autotune :)

LED Strips being wired/assembled...



I have 6 LED's under each motor, the wires are joined together and fed through the arm tube...


...Where they are all neatly loomed together underneath, this runs from the rear, has an XT60 battery connector, is then spliced off to feed VTx and rear LED's, the front LED's, then terminates right at the front in another XT60, this is where the Gimbal/Controller/GoPro get plugged in, so they can be left unplugged or removed if required (although that's not an easy task)


Green=Front, Red=Rear, And on the U/C arms i made it do 3 white then 6 coloured just to be a bit different...


Alexmos controller is mounted under the front rails, and you can just see the UBEC used to power/charge the GoPro behind it...


VTx is mounted at the rear with the antenna pointing downwards...


Just got some batteries on charge, I will then need to work out the balance and hopefully get her up in a stabilised hover out in the garden quickly to see what the APM thinks of the extra weight...

Offline PaulJC

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Re: My Alien H4 680mm Build - 30 Minute+ flight on maiden day...
« Reply #22 on: May 13, 2015, 13:53:01 »
Well, a quick hover out in the garden revealed that... It still flies :D lol

It still needs trimming now there is no wind and tuning as well, APM reports back with a THROTTLE_TRIM of 408, so 40.8% to maintain a hover, not sure about that given it was only 38% before, i'm not sure 3% extra throttle would be enough to haul up an additional 500 odd grams but i could be wrong... I'll recheck at a later date...

And on landing the motors were HOT, i have no way of telling how hot but you wouldn't be able to keep your finger on the bell for more than a second or 2, but they are black motors which were in direct sunlight for a fair while while i was waiting for HDOP to come down just in case and my phone which had been sat on the table was almost too hot to operate the screen (oops), i've ordered an IR Temp gun to see how hot 'HOT' is... If i get out later it'll be a bit cooler hopefully and i'll look in to the current draw while in hover, the ESC's were barely even warm though so i don't think it's that... We shall see, it could be absolutely fine but i'd rather test and measure and know for sure...

Just prior to takeoff...

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Re: My Alien H4 680mm Build - 30 Minute+ flight on maiden day...
« Reply #23 on: May 13, 2015, 19:07:23 »
Arrrrgggghhhhhh...!!!

TBC...

Offline PaulJC

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Re: My Alien H4 680mm Build - 30 Minute+ flight on maiden day...
« Reply #24 on: May 13, 2015, 21:11:38 »
Right, back at home from the field, had a fag and made a brew, and everyone loves a crash story (or 3) so here goes... (Oh and there will be video too...)

Head to the field for autotuning and to give the new rig a bit of a test etc... The wind has picked up a little but nothing major so game on...

Flight one, Autotune, all was going well, she done her little dance round the sky, left right, left right, front back etc etc, so at this point she was in Altitude Hold and sat quite nicely, the PID's seemed a little better but she's still rubbish at holding any kind of position in stabilise at all, have a quick look at my tablet, HDOP of 1.something, and an altitude of about 3m, switch into position hold and she just drops, not enough height to try anything, she goes in... She hits the ground harder than any of us would like but flat, result! and then falls over and lands on her side, 2 props wedged against the floor, motors screeching away, not good, so i run over while trying to disarm, grab it by the camera rails (these can easily take the whole weight) and pick her up level to get the props out of the dirt, as this happens i hear "Disarm" from the tablet and she powers down, one skid popped out of the UC arms, but the flexing of the arm pulled off all the new LED's  :banghead: :banghead: No other obvious damage, check the motors to see how hot they are and they seem fine, ESC's are barely warm, same with lipos... So WTF caused this is anyones guess, so i sit down, have a smoke, take 5, turn on the GoPro and FPV gear (Video Below) and decide i'll just hover her out over the soft stuff to see if it's alright, up she goes with no problems, sits there happy as you like in Alt Hold or Pos Hold, i start to do a pan around and she starts losing some height but nothing major, then the lipo alarm kicks in (these are set really high 3.7 per cell on the lowest cell while under load) i try to finish my piro but don't get that far, she falls, this time i have just about enough time to flip in to stabilise and pile on some throttle, by the time it had sorted itself out it caused a bit of a bumpy landing with a bounce on some soft stuff, skid popped out again, zero other damage, wtf is going on, wondered if failsafe had cut in early but that is set pretty low at 21.0 (3.5v average) so it's not likely to be that, besides, that's RTL so CLIMBING to 15m before flying back :/



So, i sit and ponder further, have another smoke (this ****** is getting stressful...), throw on a new pair of packs so voltage is not an issue, arm the copter, go to take off (listening to the video i do hear a funny sound here!! 0:34 but it goes as quickly as it starts, video below), and she falls over, props in the dirt AGAIN, i disarm, put it down to uneven ground, move her over a bit and try again...  This time she goes up with no issues at all, i have a little hover, decide i cant remember if the GoPro is still running, set her down to check to find it is still going  :banghead: rearm and up she goes again with no problems, have another little hover about, still no funny noises, flip from Alt Hold to Stabilise and have a little moment, must check my THROTTLE_TRIM again but its fine, explainable, move out over the soft stuff again, Pos Hold, and climb to 30m and pan around, she loses a couple of meters but nothing drastic, the gimbal does have a moment half way round but that also needs tuning..., cool, so no dramas, all is well with the world, a bit of tuning needs doing but now she is flying as she should... Climb to 50m, start a pan around, 3/4 of the way round and you can hear the RPM's in the video drop and she just falls!!! AGAIN!!! (6:20) Switch to another mode and pile on the power, she recovers, fly her down no problems and put her on the ground, gently this time...

(Yeah i know i should have given up by now...)

While she's down i double check the pack voltages, the OSD seems like isn't displaying any current being used (but i've not calibrated it yet, so is the voltage right as well i'm asking myself... And it was, so still 24 odd volts in the pack, loads!, lift her up in to a hover in stabilize, no dramas, no funny noises, switch in to alt hold iirc, again no dramas, decide to move over above the soft stuff just in case, and boy am i glad i did! (9:55) RPM's drop off again and she fall's (, i just manage to get it back in to a mode where i can pile throttle on which softens the blow, she's gone in AGAIN, by this point has picked up power so comes back out but i decide the ground is the best place for her and dump the throttle and disarm...

Get her back to the car, motors not hot, but front left and rear right warmer than the other 2... (Yaw imbalance somewhere...???), ESC's barely warm, Lipo cold as you like...



Now i have no real idea what is going on tbh, all plugs on the craft are secure, motors are noise free and spinning freely, battery voltage still over 3.8 per cell so it's not that, just seems when ever i actually 'fly' it somewhere that it dumps RPM's and wants to fall out of the sky, i'm really lucky to have not caused any major damage but as it'll happily hover on the spot all day long i don't really know where to start looking to find the problem, any ideas?!

The ESC's are SimonK flashed, could these incidents be caused by the known SimonK/Low KV motor Sync issue?

Have looked at the logs and i can see the APM is trying to compensate for the loss of RPM/Height by maxing out the throttle output but it achieves very little... thoughts?

I'm a bit fed up with it now, maybe time to shelve it for a while...






« Last Edit: May 13, 2015, 21:46:27 by PaulJC »

Offline PaulJC

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Here is a grab from the log:

I'm in Position hold, so should be held in Altitude and position.

The blue/green line is altitude, it doesn't look much on the graph but that drops from 50 to 15m!
The pink line is my throttle input, it goes unchanged at this moment, this happened fast, it does start changing after...
The red line is the APM's throttle output, as soon as it detects the fall it gives maximum, but you can hear in the video the RPM's don't increase for sometime...

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Offline quadfather

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Re: My Alien H4 680mm Build - 30 Minute+ flight on maiden day...
« Reply #26 on: May 13, 2015, 23:40:18 »
The ESC's are SimonK flashed, could these incidents be caused by the known SimonK/Low KV motor Sync issue?

The sync issues that I have seen in videos were usually when you had rapid throttle changes to which the ESC wouldn't react anymore. However, that sound you had at 0:34 seconds could be what's called cogging, but I only ever have seen it on high Kv motors where it sounds different.

An example of sync issues with a pancake motor and SimonK (an old video)
Clicky

There was a long thread on google groups about sync issues and IIRC the consensus was to use different ESCs, motors or firmwares. 

I have no experience with rigs of your size, but it appears to be running out of juice.  Since you mentioned that they are old packs from your helis, can you confirm the LiPos are in order?  By that I mean internal resistance, mAh charged back, etc, not simply voltage.
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I think 0:34 may have been cogging as well, my Trex 550 does it on every startup but is fine once it's going...

The APM was applying lots of very fast throttle corrections, PID's were still out and it was windy and gusty, I have just read through the google groups link (thanks for that, some good info) and my setup would be typical of the problems, high voltage (6S), low KV motors (380kv) and largish props (15"), from reading that page the problem can also be compounded by turbulent conditions of which i had aplenty today

The lipos have been used in Heli's, but are all under a year old and would be surprised if they have had 15 cycles each (i've got 6, that would be 90 flights, very unlikely i have done that many...)

I agree that it does appear to be running out of juice, and in the video also sounds like it too, but the copter was fine to then go on for another flight, maybe enough battery recovery who knows, maybe i'll have to finish putting my new Logo together and see if its the batteries by crashing something more expensive lol

In reality i think i'm going to have to pull the quad apart (again...) and see if i can replicate the issues on the bench...

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OK, just re-read you first post.  :slap:

EMAX ESCs don't run SimonK.  They have Silabs MCUs which SimonK doesn't work on.  It's buzzword bait.

However, these ESCs have a low-voltage protection feature.  With my EMAX 12A SimonSeries ESCs this had always been enabled from factory.  Essentially what it does is that the ESC lowers the motor output once it hits the threshold thus slowly (or not as the case may be) descending the aircraft.  This would pretty much look like what you see in your videos.  If your batteries are spent you hit that threshold much quicker and the LVP kicks in.  Once on the ground the battery recovers and you measure a voltage much higher.

I'd highly recommend a programming card. These are usually specific to the brand or firmware.  For EMAX you want this one http://makeitbuildit.co.uk/index.php?route=product/product&path=75_32&product_id=213.  The ESCs could be programmed using the throttle stick and your radio following a sequence of beeps, but it's an excruciating exercise.  With the programmer is a few button pushes and you're done. ~~

The programmer also lets you configure other settings.  Perhaps they can be improved to eliminate that sound you had at the beginning of the first video.  I only ever tweaked the ESCs for high Kv use, so I'm afraid I can't suggest anything there.

Hope it helps.
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Well unsurprisingly my Giant Shark order of motors didn't arrive today either as that would have made bench testing a bit easier as the ESC are fairly easy to remove from my build but the motors are not, i may just remove all props bar one and strap her down, having figures for a single motor current draw etc wouldn't be a bad thing anyway, i could try to replicate what has happened as well, but strapping down an airframe is far from ideal...

I appreciate what you're saying about LVC but i believe that is set at 3.0v per cell, there is no way in a million years any of my batteries hit 18v at any point, the ones that were bleeping in the video were sat on 3.65-3.70 when they were tested back on the ground and the others didn't get drained that much and were still sat on 3.8, but you are very right that it could potentially be that so i will eliminate it from the equation...

I'm starting to think if buying programmers etc if i might as well just buy the adapter to flash them with BLHeli and be done with it, i haven't read enough about it to know what i'd need yet though but it could be a potential solution to all the problems, thats is if indeed they are ESC related...