Quad Please help!

[NEIL]

Hi guys, I'm new here so bear with me if I come across as a total noob!

I'm a cameraman by trade and have ventured into the world of aerial video.

I bought a nice simple 450 quad to get to grips with multirotor flying. I seem to have got the hang of it so far.

I had a pretty bad crash in the first few days, had to rebuild (new ESCs and motors), got it up and flying again (better than it did before, pretty stoked on that!), had what seemed like a not too serious crash yesterday, knackered a couple of the motors, so replaced again with the same type. Reset everything, recalibrated the ESCs etc. etc. and now when I try lift off, it just flips over to the right hand side.

Can anyone help me with this at all? I've tried everything I can think of and it just keeps doing the same

Any help will be much appreciated!!!

Thanks,

Neil

 

[Karubah]

GDay Neil, Welcome to THE forum to be on. Just a few things first. Can you tell us what sort of quad, what gyro or control board and radio you are using? We need a starting point and if you can post a pic that will be good. There is plenty of people willing to help here.

 

[NEIL]

GDay Neil, Welcome to THE forum to be on. Just a few things first. Can you tell us what sort of quad, what gyro or control board and radio you are using? We need a starting point and if you can post a pic that will be good. There is plenty of people willing to help here.

Hi Karubah,

thanks for the fast reply!

It's a black crow 450 frame (X config), kk2.0 v1.5 board, spektrum dx6i radio, orange 6ch rx, hobbywing 20A esc, emax cf2822 1200kv motors, 2200mAh 3s LiPo, 8x4.5 props (i know they are a bit small but it made it way more stable, but radically reduced flight time unfortunately!)

It powers up fine (all props starting at the same time) but when I rev up to take off speed it looks like it's going to fly and then just flips over onto the right side. It's on all the same settings it was before the crash and minor rebuild so all trims are the same. It did work for a minute or two yesterday but was yawing hard to the left when it did get in the air and wouldn't climb very far either. I thought maybe i'd damaged the self-level or something but it does the same whether that's on or off. I am most confused!



- - - Updated - - -

here's an example of it flying before, no gimbal or post stabilisation

http://youtu.be/1KkhOz2aB94

 

[Karubah]

okay the first thing I would be doing is go back and reprogram everything. I know its a bit of a pain but it pays to recheck. Check all wiring and joins including solder joints and plugs. This should give you a starting point and we can then work from there. You may have already done this but just might be worth doing again.

 

[Lee]

Welcome to the forum Neil. If the settings are the same as before, then it may be mechanical.
Check you put the props on the right way CW and CCW on the correct motors.
Check the Props aren't slipping. (Maybe you stripped the grub screw holding the shaft os the motor, and its spinning or slipping under load)
These maybe simple things, but we have to start somewhere.
Let me know, and we will go from there.
Cheers Lee

 

[NEIL]

Welcome to the forum Neil. If the settings are the same as before, then it may be mechanical.
Check you put the props on the right way CW and CCW on the correct motors.
Check the Props aren't slipping. (Maybe you stripped the grub screw holding the shaft os the motor, and its spinning or slipping under load)
These maybe simple things, but we have to start somewhere.
Let me know, and we will go from there.
Cheers Lee

Hi Lee, thanks for your help!

Yep, checked the props, they are on the right way, they do not slip on the bullets, the shaft doesn't slip either (full throttle there is no slip on the motor when I push my finger against it, to the point of it stopping).

All the props spin when I try to take off, throttle up as slowly as I can just make sure it's not a safety feature kicking in and reducing power to m2 & m3, it lifts a little on the left side and then flips over to the right.

- - - Updated - - -

okay the first thing I would be doing is go back and reprogram everything. I know its a bit of a pain but it pays to recheck. Check all wiring and joins including solder joints and plugs. This should give you a starting point and we can then work from there. You may have already done this but just might be worth doing again.

Yep, re-soldered everything last night (after it started acting this way, it had taken off the first time I tried it after replacing the motors after the crash and it flew but yawed hard left, even when I pushed the sub trim all the way right). all connections are good as far as I can see. Motors fire up at the same time, the test beeps come on on all 4 when i connect the battery, reprogrammed it to the exact same settings as it was on before, recalibrated the ESCs too.

 

[Lee]

Take the props off and put a little flag of tape on each motor shaft.
Spool up to a set RPM and put you finger or something in the tape to listen to the noise. See if all four are the same.
Rev up and down, give aile and elev inputs, try yaw, how does each motor sound? This will give you an idea of what the motors are doing, without the danger of the props.
Yawing hard right mean that the front right/back left are too fast, or front left/back right are too slow for some reason.
Good luck pal

 

[NEIL]

cheers, that's a great idea (hadn't thought of checking it that way!) I did listen to the motors before without the props on (after i recalibrated the escs) and they all seemed to be making the same sound) but the tape idea is awesome!

 

[NEIL]

right, done as you suggested, and the motors were spinning at different rates.

Took it all apart, reset, retuned and recalibrated, now I can get it off the ground but it's super unstable still and yawing to the left... anymore ideas?

 

[Lee]

If you haven't already, check out the KK tuning video. And watch out for the chicken at the end

Multicopter PI-tuning: How to recognize different settings. - YouTube