Hi you all.
I'm new to arducopter drones, and drones at all..
I've built a Quad, using APM 2.8 Board (non-3DR), M8N Gps, 470kv 24p motors, 15x5,5 CF props, and tarot 650 CF frame, all running on 4s 10.000mah and turnigy 30A Plush ESC.
In the beggining all worked fine, i'm started to learn how to pilot the Quad, using stabilize and loiter. obviously loiter resulted more attractive because was hard to me maintain altitude when making horizontal displacement in stabilize..
some day the quad started to toiletbowl and i got scared and did everything wrong and crashed at high speed to a 25 meters tree, cutted off some branches, and fall down. Result: 1 broken arm, 2 wasted props, and complete landing gear destruction. apm and gps was scratched too.
recently i fixed the aircraft, and this time I DID COMPASSMOT (not done before!), to avoid toiletbowling. I mounted APM with 4 3M slow response foam earplugs in a double plate, and sticked to APM and frame with double-doublesided foam tape.
In stabilize is rock solid, but alt hold and loiter works weird.....
in loiter, when you let the quad hovering, it twitches the throttle, like an angry bee, i don't know how to explain. it's like the quad stops and re-run motors for a fraction of a second, and looses about 2 or 3 inches of altitude and go up again. its like a glitch. I tried to fly loiter anyway, was making squares about 2 meters above ground to practice, and suddenly... quad rocketed up in the sky... this time i was ready, and switched to stabilize. the quad started to fall, and with a throttle punch it leveled again, but at an altitude i never used it... so i decided to switch to LAND mode, and the quad suicided itself drifting away and descending too quick. this time: 2 more props wasted, and a crack in the lower main plate. gps stand was destroyed as usual..
i spended much money to start my aerial filming project, and i do not trust this aircraft to hang a professional camera on it. i thought it will be like a phantom, but bigger, nicer and stronger, capable of carrying a full dslr camera. But it is only a big and dangerous machine, and i'm hating it so hard.
i will leave you the last flight logs. if somebody with experience and expertise give me a hand and analyzes my logs, i will thank you very much.
i can only think i have a vibration issue, so i ordered a moongel pad to reinforce damping.
The big problem is i'm in Argentina, and any replacement part or upgrade takes a month to arrive, and a ton of paperwork to claim it in customs..
looking forward to fix this, and sorry for my neanderthal english.
there is a lot of ardupilots flying out there without rpm feedback from escs. i just want mine flying like those.
and i don't want to spend any more money on it.
I need log files for the correctly tuned and correctly controlled, responding DIYQuad
of your type or alike
I've built a Quad, using APM 2.8 Board (non-3DR), M8N Gps, 470kv 24p motors, 15x5,5 CF props, and tarot 650 CF frame, all running on 4s 10.000mah and turnigy 30A Plush ESC."
to study correct log data charts (signatures) vs. your log data charts (signatures)
- Master follow Yoga approach
My friends developed in San Francisco micro jobs service turned into global success.
Just offer $5 or $10 reward for:
"I want you to tune my quad to fly safely"
Contact sellers of your quad's hardware parts asking them if the delivered parts
has beeen pretested to fit your Quad type, airframe -
ask them if the parts have been Drone Certified (TM)
It may be the case, delivered hardware parts have inbuilt limitations to work properly
for your Quad configuration.
Ask every seller for a manual for every part, technical specification, performance charts.
Contact manufacturer of your airframe for resonance frequency charts, frequency ranges.
It may be the case, your airframe if not fit for your project and there is no solution
to damp amplitude of resonant frequencies within a given RPM range .
We are not lazy but I have studied interactive media, communications at MIT, MediaLab, MediaMOO 25 years ago, so if charts have been attached by you, we can easily discuss the problem in interactive way.
If not, how could we find solution to your problems.
So now I need ppl to attach log files to feature safely flying quads
to build Yoga Follow Me library of the correct data signatures for
Acc, Baro, Speed, Gyro, GPS ... charts.
Just offer $1 for the job to be done for you in public.
Payment via Paypal
If $1 cannot do the trick just ask "how much" and forget your problems soon.
Ppl from San Franciso did hundreds of micro jobs that way.
I don't know why your z acceleration changed, but it is still within acceptable limits. If it flies fine in stabilize but poorly in alt hold, that means you need to tune throttle. See this page for help tuning. Like Darius said, you could also seek out an experienced user to help you tune.
I wouldn't bother talking to manufacturers. Multirotor hardware is all sold as is, with no guarantees of compatibility. And almost zero parts will list resonant frequency (which is not even your problem here, your problem is tuning.) And Drone Certified (TM) is a term made up by Darius, it is not real.
Stephen: Thank you for taking the time to write. May be the windy conditions yesterday making a difference in my Z axis? i will read carefully the page you said. May autotune be a previous step to manual tunning? or is preferable to first do a manual tunning and then go for autotune? please give me advise on this, because i'm going all-in on tunning.. :D
I live on a small town in patagonia, so i'm sure there is no other apm users in here to ask for help. i'm on my own with this, and counting on community help like yours.
i will not bother manufacturers... calling china to complain for my own lack of knowledge sounds foolish. may be i can offer darius a million dollars to come here and help me. Thath sounds like a good idea!! lol
I think your focus on tuning will help your situation. You only need very basic performance in alt hold to do your auto tune.
Sometimes, it is necessary to change the PID setting before getting acceptable alt hold performance.
In my case with a heavy Y6, I needed to set estimated settings to get off the ground. If you feel completely out of control then you might need to read and try to understand the PID settings so you can manually change the settings to achieve rough alt hold. The a successful auto tune will then get you more stable.
Hey, I forgot you stated the APM wont support autotune? Are you sure? Well, if not, the Wiki has good information on tuning prior to autotune. Read everything first, then setup a tuning knob on your remote to ch6, then tune one PID value at a time, very carefully. Tuning is a big topic, but will make your craft stable. You have no hope for stable flight with a home built drone without tuning.
Thanks Harry! i didn't want to state apm don't support autotune, sorry if i did that. My english isn't so good. I saw a lot of vids on youtube showing arducopter autotune on apm copters. i tried to ask what should i do first: Manual PID Tunning or Autotune?
Now, here we are facing our second day of windstorm "Puelche", so no chance of flight. in addition, winds are raising volcanic ashes from the ground (from last eruption of a chilean volcano relatively close) and going out is messy and "Ashy". So, using free time indoors to read and prepare action for next windcalm day. May be good if i upload some pictures of the quad so everyone can see my build and look for any mistakes.
Juan: APM and 3.2.1 supported autotune pitch and roll, not supported yaw; you need to have a reasonable alt hold to use autotune, If you can´t fly in Alt hold, you need to be able first or you are in crash risk.
Yes, windy made the difference, your z vibes looks well, your x and y are bigger, I hope for your props near the controller.
-- I wouldn't bother talking to manufacturers. Multirotor hardware is all sold as is, with no guarantees of compatibility.
-- i will not bother manufacturers... calling china to complain for my own lack of knowledge sounds foolish.
It's easy to email every manufacturer on the globe and get kind reply and advice next day.
My friend just replaced 50 broken LED bulbs directly with China manufacturer
for free in one day.
-- Multirotor hardware is all sold as is, with no guarantees of compatibility.
Manufacturers of MR hardware parts are really friendly guys, represented at rcgroups.
You can get full service, advice, manuals for free.
They know they business very well supplying RC developers for years.
If you are building DIY Drone from a Kit you exactly need to source hardware parts to match each other, exactly as in professional aircraft industry, equipped with labs, testing sites and full staff.
- And almost zero parts will list resonant frequency
Selecting low resonance airframe is basics for your success since resonant vibrations can damage motors or shorten their life cycle, can damage sensors, connectors, battery.
If you source for electronic parts to be exposed to resonant vibrations of airframe,
you really need to tell about it to supplier or manufacturer.
-- And Drone Certified (TM) is a term made up by Darius, it is not real.
I hope Drone Certified (TM) to win global recognition in RC worlds within next few months as a global standard.
So Drone Certified (TM) is exactly for real,
by Open Technology Park,
Open Fabrication Labs
Today i'd make some progress. i managed to have 2 altHold flights, both very stable and easily controllable.
I did the on-flight Rate P roll & pich tunning, using a knob on the Tx. I got comfortable with the exact point where, if you do a repentine roll request, and immediately release the stick, te copter levels itself without "bouncing" in the air. now the quad flies like hanging from a thread :D
vibrations decreased a bit on X & Y, by adding weight (strapped radio Rx and GPS/Compass module to it)
Cala told me the vibs are because of a workaround repair in the airframe. an arm was broken in a big crash and i'm waiting for the repacement (1 month average shipping time to here....) meanwhile, i displaced the motor mounts about 5cm to center, to make all the same lenght of the broken one. this crappy repair makes the propellers spin with only 1cm clearance between each other, and slightly over the center plate. i'm using 15"x5,5 props. maybe, this is making turbulence and messing all up.
both flights ended in light crash. the first one was due to depleted battery. so i set a battery failsafe at 13v (i'm on 4S) to land the aircraft.
second flight also ended on crash. battery failsafe was triggered at 13v, and copter suddenly outed high throttle,but anyway descended sideways too fast and hit the gruond. if that is the land manouver, it should be called autokill_land! just kidding, surely there is a tune to do, to get a soft and nice landing.
by now, i'm feeling comfortable with althold, the new P rates are awesome, there is a big difference!
the only thing left to go for autotune, is that creepy automatic landing. there is any way to get it working now? or LAND mode is a further step?
in both flights, i was using only one battery (Zippy 4S 5000mAh 20C), and only charged to storage level. the copter is intended to flight with 2 of these batteries, but since i was only tunning things, i didn't charged it to full capacity (my mistake, i know), and mounted them one by one.
logs are attached . if anyone can take a look and give me advise i will tank you.
PD: in one of the crashes, props cutted off RC Rx antenna, and a very nice repair/mod was done. i will upload the process step by step in another post, with pics, so anyone who cuts its antenna know how to repair and enhace the Rx.:)
Congrats Juan, but fly with full charged batts,
If you are going to fly with two batteries you have to tune with the two batteries, weigth change tunning,
buy a little batt alarm, it's very usefull with APM,
recalibrate your compass if you move it and verify that works well,
your vibes looks nice.
Well..... not a very nice day today!
I decided to do a previous step before autotune. try to spend all two batteries doing a quiet and nice althold flight, just to be sure of stabilty.
flight last only 1 minute or so...
take off in stabilize, and above 1 meter from ground, switched to althold. altitude went lock as expected, but a light wind suddenly started to raise. i had to maintain a light roll angle to hold position.
then, quad started to climb very slowly, without input. i lowered throttle a bit, but it kept climbing.
when it reached about 2 meters high, i lowered throttle a lot, expecting some descent, all this maintaning slight roll angle to hold position. suddenly, quadcopter started to climb very fast, to about 10 meters.
at this point i got scared, and switched to stabilize, to try a manual landing. of course, when stabilize came in, quad fall like a rock (yeah, throttle stick was all way down...) i tried to hit a throttle punch to stabilize but the aircraft was already in a compromised position so it never stabilized (no time to do it i guess).
luckily, only 1 prop was broken, but i'm out of those. they are coming in the same shipping the replacement arm is coming. so... no more tests upon arrival.
If any of you can take a look at the very small log, and figure out WHAT HAPPEND? WHY IT CLIMBED ON IT'S OWN?
i was feeling very comfortable, i was feeling on control of what aircraft do, but today something totaly different happened, he did things i never commanded, flown away out of control, and crashed, again. :S
Thanks for your help.
Could you attach log file charts for on-line analysis ?
BarAlt, GPSAlt, ThrOut ThrIn, AccZ, Y, Z, Battery chart ?