I have a tarot 680 quad copter platform with the following configuration:
1- Gforce 3542-1200KV motors
2- 12x6 propellers
3- 60A ESC
4- 4s 7500mah battery
5- (X) setup
6- weight right now about 6 lb.
My copter is very aggressive and unstable that I even could not lift it off the ground. I have done all types of calibration and lowered the PID gains to their minimum values but with no luck. What do you think the problem could be?
I run my 12 inch props on 610Kv motors on 4S.1200Kv sounds a bit high to me.
Post a log and we’ll have a look though.
Yes sure, here is a log of one of my tests indoor and be noted that I couldn’t hover it because of the wobble.
8 12-31-1999 7-07-28 PM.bin (764.5 KB)
You’ve got the lowest PIDs I’ve seen.
You want the ATC_RAT_PIT_FILT, and the ATC_RAT_RLL_FILT, set to 10 for the big props.It makes a difference.Then see if it takes off and hovers in Stabilize.If it does,autotune it.
…and I think you’d be better with the stock loadout for starters.That usually gets a copter in the air ok.
Trying to pussyfoot it off the ground never, ever works with a new build.Only with well tuned copters.And indoors isn’t a place to be doing that with a copter this powerful.I’d be fifty yards away with something to duck behind.I’ve had a big hexacopter fly at me and it isn’t something I’d recommend in a hurry.
Talking of power…50 plus Amps without taking off is scary.Which is either a badly calibrated power module or the motors sucking a lot of power.Hate to think what it would draw on a full power take off.Check that out as soon as.It could simply be that the motors are way too fast for these props.
And probably the first thing to look at is the fact that these are airplane motors in a quadcopter.Rated for 10 inch props on 4S or 11 inch on 3S.On a plane.Looks like on full throttle they’d draw 200 Amps as a set.That’s a very short and posibly smokey flight in my mind.Dump them and get some copter motors.Something around the 6-700Kv mark.You’ll be wanting to draw around 25-30A in a hover,not before take off.
Thanks Jagger for your detailed reply.
I actually replaced the motors yesterday with 4222-650KV ones and decided to get back to the default PID gain values that the pixhawk came with. and guess what it did really work. Infact it doesn’t need any kind of tuning because it feels very responsive and stable.
Nice one.It’s nice to be confirmed correct in my assumptions and even better that you sorted it out quickly.
An autotune result may surprise you.Done in Pos Hold I found it quite relaxing and got a really nice copter afterwards.