Problem with one of my props

[Gunner]

Not sure what's going on. I've not crashed the QX, but all of a sudden, one of the front props will stop turning while I'm flying. The other 3 props continue to rotate, so I see little impact from it. But this is something that just started a week or two ago. I thought maybe there's a short in the wiring. It is intermittent and usually happens when I use the rudder to turn one way or the other. Do you think its a motor problem or a board problem?

[Pfloyd]

Re-Bind the QX and make sure it is flat and level.

[lenix38]

Are you losing power/altitude when you notice one prop stopping? Also are you turning or banking really quick when you notice one of the props slowing down or stopping? If so this is normal, my 180qx does it too. As long as you dont lose altitude and shes controllable you should be good.

Now if this is happening even on initial spool up, and your losing power or/and altitude than its a serious issue.

[Gunner]

Normally, I can still maintain control. And it doesn't lose any altitude before it starts spinning again. But when I first bought the QX, this didn't happen. I flew it for several months and all props always turned. It worked great. This just started a month or so ago. Now the problem I have is that it's gone. I was flying today in a nice brisk breeze. Going down wind, it was fine and moving bast. But when I tried to bring it back, that one prop would not continue to spin. So with the wind, I couldn't get it oriented back to me. The wind was too strong with only 3 props turning hard. So it drifted away into a field somewhere and I never found it. I kept it up in the air as long as I could and then it got so far away that I really couldn't tell which way it was going. So I landed it somewhere in a field. It was easily 500 yards away. I looked for it for a long time. But no luck. So I guess I don't have the problem anymore!!

[xr3tf]

I just noticed this thread after my 180QX started suffering from similar symptoms today.

I have had the quad now for more than 6 months and have put quite a number of hours on it, without any hassles (apart from almost losing it a few times).

I noticed today that sometimes when I wanted to turn left using yaw and roll controls at the same time, that it would not respond at first, sometimes for a split second, other times for a second or two. The problem is intermittent however and it does not happen all the time - I would say about half of the times that I try and use this combination of controls. When it reacts normally, it flies as well as it always did. I notice that the left front prop seems to be static quite often, but not sure if it is related issue.

I have done new binding a few times, and also tried the radio (DX6i) on my Nano QX and all seems well. I thought that the giro might have been getting confused because some of my props (left front and righ rear) were a bit wobbly, so replaced all four props with new, but that made no difference.

I would appreciate if someone can advise on more ways to try and identify the problem.

[eKretz]

You may be at the lifetime limit of the motors. When they are getting close to worn out they get slower and weaker. Sometimes they won't start until a higher voltage, and then the quad will shoot up like a rocket. Is it hard to keep at a stable height with small adjustments, like to slowly go up or down? That would be a pretty good indicator. Mine is getting to where the motors are about done as well, I'm going to pick up some new upgraded ones from MMW soon.

[xr3tf]

I will test it again in the morning to see what happens with small corrections. The feeling that I got was exactly like you mention - I need to give it maximum input to get it to turn left, but it is intermittent which is a bit confusing.

What motors are mainly responsible for turning to the left? I have noticed that when it "gets stuck" for one or two seconds, the right hand side of the quad drops slightly.

I read somewhere that the lifespan of the standard motors is about 6 hours - is that more or less accurate?

[eKretz]

To turn in any direction I think the quad will speed up props at opposite corners that rotate opposite the desired rotation and slow the ones that rotate the same as the desired rotation. So if you want to go left, or CCW, it will speed up the props that rotate CW and slow the props that rotate CCW. So to go left it will speed up the front right and rear left props while simultaneously slowing the front left and rear right props.

I have heard 6 - 8 hours lifespan on the motors, but no idea if that's accurate. I'm sure it would be highly dependent on the amount of abuse and high-load conditions the motors are subjected to.

[Pfloyd]

Originally Posted by eKretz

To turn in any direction I think the quad will speed up props at opposite corners that rotate opposite the desired rotation and slow the ones that rotate the same as the desired rotation. So if you want to go left, or CCW, it will speed up the props that rotate CW and slow the props that rotate CCW. So to go left it will speed up the front right and rear left props while simultaneously slowing the front left and rear right props.

I have heard 6 - 8 hours lifespan on the motors, but no idea if that's accurate. I'm sure it would be highly dependent on the amount of abuse and high-load conditions the motors are subjected to.

My MQX which I bought when it first came out and have been flying it a lot has never had a motor die. Are you giving your 180QX at least a 10 minute cool down before flights?

[xr3tf]

I tested the 180QX today just hovering around with small inputs and it worked 100% for six minutes.

I will test it outside again when weather permits - I was working it quite hard the first time it happened, and subsequently it was also working relatively hard when it did not respond.

I often touch the motors to check temperatures, but it has never been excessively hot. It is quite cool at present so air cooling also seems to work better. I do not cool the motors down between flights - just swop battery and up it goes again, and again...

My quad has definitely done more than 6 hours flight time, and I would guess even more than 8 hours, as I only started to log hours recently and it is already past 4 hours.

[Pfloyd]

Originally Posted by xr3tf

I tested the 180QX today just hovering around with small inputs and it worked 100% for six minutes.

I will test it outside again when weather permits - I was working it quite hard the first time it happened, and subsequently it was also working relatively hard when it did not respond.

I often touch the motors to check temperatures, but it has never been excessively hot. It is quite cool at present so air cooling also seems to work better. I do not cool the motors down between flights - just swop battery and up it goes again, and again...

My quad has definitely done more than 6 hours flight time, and I would guess even more than 8 hours, as I only started to log hours recently and it is already past 4 hours.

I would wait at least 5 mins between batteries.

[eKretz]

Like I said, the 6 - 8 hour thing is just what I've seen bandied about. It doesn't necessarily mean it's true. My qx is a bit over a year old, still on the original motors - and it gets hours between flights normally. The motors aren't dead, just not as good/peppy as they were new. Motor problems can be intermittent too, as heat can influence motor performance quite a lot.

[xr3tf]

I tested the quad outside today, and could replicate the "non-turning" result probably 60% of the time when I would be flying straight ahead at speed and then wanting to bank/turn left. If there was a delay in turning left, once it starts to turn I can spin it around without end.

I tested temperatures on motors - all within two degrees from each other - 18-20 degrees C.

I am flying in high rate stability mode, which probably masks the problem a bit. I will try it on agile tomorrow to see if I can identify something else.