LibrePilot Forum

Users => Vehicles - MultiRotors => Topic started by: dcgm19 on July 25, 2016, 03:39:59 pm

Title: New build with cc3d quadcopter not working
Post by: dcgm19 on July 25, 2016, 03:39:59 pm
Hello All

I am building my first quad and I am having terrible luck trying to get this to work. I followed all the everything and did all the wizards yet a few odd things are happening. The first issue is when I give it a tiny amount of throttle the motors spin up but get faster and faster even when I only gave it like 5% throttle. second issue is once its in the air it just goes higher and higher and wont come down. It's also very unstable. The third isssue is about 1/5 times one of my motors does not idle correctly and no matter how much throttle I give it it stutters and gets hot.Now I beleive that may be a bad esc. I did all the calibrations and this thing just wont fly properly. The first few times it would flip over for no reason i had to run the wizard a few times to fix that issue. here is a link to the kit I purchased http://www.aliexpress.com/item/Carbon-Fiber-ZMR250-C250-Quadcopter-2204-2300kv-Motor-Emax-BLHeli-12A-Esc-CC3D-EVO-Flight-Controller/32680035735.html

Any help would be greatly appreciated!
Title: Re: New build with cc3d quadcopter not working
Post by: f5soh on July 25, 2016, 03:48:52 pm
Hi, welcome.

First you should resolve the hot motor with spinning issues. Having one motor issue is not optional if you want to fly correctly.
Can be a defective Esc or a screw that do contact with motor wires.

The Rpm that increase while applying 5% throttle is normal, the board accumulate the small error (The I term from PID) and try to compensate but cannot finalize because frame to not move at all.

Title: Re: New build with cc3d quadcopter not working
Post by: dcgm19 on July 25, 2016, 03:51:53 pm
So for the motor issue Im not positive it's the esc but it does react the same way when I put a known good motor. Also the screws dont reach the windings so I dont think thats my issue. When I give the motor full throttle a few times then it will spin properly eventualy. When it did fly it would just go higher and not respond to my controls until I fully cut throttle the motors just kept gaining speed.
Title: Re: New build with cc3d quadcopter not working
Post by: f5soh on July 25, 2016, 04:54:14 pm
So if you don't see any issue with motor that need to warm for proper behavior, all is fine :)

Title: Re: New build with cc3d quadcopter not working
Post by: dcgm19 on July 25, 2016, 05:00:46 pm
I am going to replace the esc. Do all 4 need to be identical?
Title: Re: New build with cc3d quadcopter not working
Post by: f5soh on July 25, 2016, 05:21:33 pm
All Esc and motors should be the same for a Quad.
Title: Re: New build with cc3d quadcopter not working
Post by: dcgm19 on July 25, 2016, 05:47:57 pm
Here is a video of whats happening with one of the motors
https://www.dropbox.com/s/12wh8vt83j45dmt/VID_20160723_223356.mp4?dl=0

is this the esc or the motor giving me the problem?
Title: Re: New build with cc3d quadcopter not working
Post by: ernstock on July 25, 2016, 10:45:16 pm
Hi
Have seen that sort of behaviour when one wire to the motor is badly connected , and also
when motor screws shorting.
( even if they look like they
Aren't touching , back them off - see if it helps , maybe take each one out and check nothing has come off the thread and into the housing )
( also seen it when the rotor has been damaged on impact but you would notice it wouldn't spin freely by hand)
Yet you say the behaviour is the same with a known good motor ,
Are you soldering motor wires straight to escs ?

Title: Re: New build with cc3d quadcopter not working
Post by: dcgm19 on July 25, 2016, 10:54:58 pm
Im soldering the cables from the esc to the motor and i have good connections i think. The screws are not nearly long enough to touch the motors insides.
Title: Re: New build with cc3d quadcopter not working
Post by: ma70snowman on July 26, 2016, 02:01:16 am
Here is a video of whats happening with one of the motors
https://www.dropbox.com/s/12wh8vt83j45dmt/VID_20160723_223356.mp4?dl=0

is this the esc or the motor giving me the problem?

had the same thing with mine.. replaced the ESC.. no more problem.

mine will flip like you're explaining from time to time, and it's usually because the FC didn't boot correctly. I usually give mine a test spin up to see if it acts normal, if not I unplug the batter and plug it back in and it fixes that. but this is just my experiance w/ my Quad... couldn't tell you WHY it's happening that way though.

Title: Re: New build with cc3d quadcopter not working
Post by: dcgm19 on July 26, 2016, 03:17:37 am
i have a new issue i can get it to fly even with the bummed esc but the i can hover it with about 20-30% throttle the second i go past thiry the thing just keeps climbing and wont stop. how do i stop this i dont want this thing climbing that fast and when i try to bring it down the second i get back to 30% it drops out of the sky.
Also another issue is one of the known good motor and esc pairs give me the same problem as my video when i put a prop on no matter what i set the idle. no prop is starts and spins fine with prop it stutters no matter what the throttle is.
Title: Re: New build with cc3d quadcopter not working
Post by: dcgm19 on July 26, 2016, 04:23:22 pm
so the bottom right motor only spins funny when i put on the prop and the bottom left one does that no matter what. see the video
https://www.dropbox.com/s/jx7nidgqbqcbvvb/badmotor.mp4?dl=0
Title: New build with cc3d quadcopter not working
Post by: ernstock on July 26, 2016, 09:27:47 pm
Hmm , some motor wires ( often Emax 1806 for example ) have lacquered wires which are exceedingly tricky to solder well , once the tinned end cut off.
Have you cut the motor wire length ?
The really evil thing is that the wire looks like shiny copper but is shiny (solder resistant ) laquer -coated.
Forgive me if you already know this.
As far as the altitude control goes , I wonder if it could be mitigated with some flattening ( and general lowering )of the throttle curve. There's one in the gcs and also on some tx.
Title: Re: New build with cc3d quadcopter not working
Post by: dcgm19 on July 26, 2016, 09:41:24 pm
i have not trimmed the wires but i have  un soldered and re soldered them a few times
Title: Re: New build with cc3d quadcopter not working
Post by: dcgm19 on July 27, 2016, 01:18:09 am
Well I for sure know its the esc im surprised all of them didnt act up because i removed the heat shrink on all 4 and i notices the soldering for the 3 motor wires are horrible and that they are touching the little chip thingys as you can see in my photo https://www.dropbox.com/s/v5936wh8zniuvr6/IMG_20160726_191018.jpg?dl=0
Title: Re: New build with cc3d quadcopter not working
Post by: ernstock on July 27, 2016, 09:24:22 pm
Yeah , from my limited experience , the motors looked like they had a bad connection somewhere.
Remember - you're not building quads to save money ! get some reputable escs and get flying !
Title: Re: New build with cc3d quadcopter not working
Post by: dcgm19 on July 27, 2016, 09:28:02 pm
i junked al 4 crap esc and ordered some little bee 20amp hopefully this will get me flying
Title: Re: New build with cc3d quadcopter not working
Post by: NicholasDavid on July 27, 2016, 09:59:04 pm
It should, the little bees have a great reputation.  A little electronically noisy. But durable and super fast. Pretty easy to tune with also....
Title: Re: New build with cc3d quadcopter not working
Post by: dcgm19 on July 27, 2016, 10:00:31 pm
now the only issue is I need to find out why when i give more than 30% throttle the thing climbs to no end.
Title: Re: New build with cc3d quadcopter not working
Post by: TheOtherCliff on August 04, 2016, 09:08:02 am
Vibration or too much D term in the PID will cause the gyros to report invalid angles.  The FC will try to correct those angles and an instant later will get a valid angle and have to correct back.  This jumping around has the effect of making it climb because the motors are always spinning up and down, but they spin up faster than they spin down.

Straighten or replace bent motor shafts.  Balance and track (track means that you get one perfect plane from the side, wrong is two because one prop tip is higher) your props.  Finally, increase GyroTau (Configuration -> Stabilization -> Expert -> GyroNoiseFiltering) a little (maybe from .005 to .010) but beware that this slows down the reactions and requires lower PIDs.