Hi

Flew my hex x a few days ago and it flew great. Over 50 mph and very stable. Pixhawk came out of an Iris+. DJI e310 kit.

The following day I was getting compass errors. Calibrated it several times and it was okay. Took off and it was very shakey. Then it just went up and would not come down. The battery was low so it only got to 300 feet all before it came down.

I reconfigured it as a quad because two motors burned out.

I put on a new pixhawk mini and had issues with the motors not spinning right on px4 firmware. Motor spun according to the pitch of the uav. Put on ardu 3.4 latest stable and motors were working good.

Flew around for a while at 40 feet. Quad was very shakes again.

Suddenly it started going up. This time it had more battery remaining. Went into land mode. Still going up. Rtl still going up. Althold same thing.

Looking at the thr in it was at minimum. Thr out was at max.

Battery gave out around 12000 ft.

Any ideas what could be causing this or what to check for?

Regards

Views: 738

Reply to This

Replies to This Discussion

Thanks for that info. It sounds like I need to look at different mounting hardware. Not sure what can be done about the electronics unless it could be heated by the battery. The change in temperature over the flight duration might make it even worse. It's pretty rare to see those kind of temps but -15 or so is fairly common.

Strange thing with a quad that flew well at -40 did not fly very good at 26 to 28 F. It would start out good and then it would drop altitude suddenly appearing to be underpowered. Sometimes it would even bounce off the ground. But most if the time it would regain altitude before it hit the ground. It would reach a point where it could not move at all and had to be flown back. There was wind but it did not appear to be the cause of this. Eventually the power module / 4 in 1 esc burned out.

Regards

Hi David,

I like 4 in 1 ESCs too, but you do need to ensure that sufficient air gets past them to prevent their overheating, in particular on the metal plate (heat sink) side. It is probably better to install them on at least 1/4" standoffs, rather than stuck flat against the frame.

That said, I doubt they like -40 either and their internal components are almost certainly not actually rated for it.

In electronics we tend to worry most about over heating, but in reality, most electronic components are not even rated for zero degrees and many will have problems as sub zero temperatures drop lower.

As  more and more multicopters are flown in colder environments, no doubt this will be addressed more fully, but for now it is a minefield you have to sort out largely on your own.

I might add, most of the plastics and resins used in the frames become extremely brittle and break much more easily at those temperatures as well, including CF and G10.

Best,

Gary

Thanks




Gary McCray said:

Hi David,

I like 4 in 1 ESCs too, but you do need to ensure that sufficient air gets past them to prevent their overheating, in particular on the metal plate (heat sink) side. It is probably better to install them on at least 1/4" standoffs, rather than stuck flat against the frame.

That said, I doubt they like -40 either and their internal components are almost certainly not actually rated for it.

In electronics we tend to worry most about over heating, but in reality, most electronic components are not even rated for zero degrees and many will have problems as sub zero temperatures drop lower.

As  more and more multicopters are flown in colder environments, no doubt this will be addressed more fully, but for now it is a minefield you have to sort out largely on your own.

I might add, most of the plastics and resins used in the frames become extremely brittle and break much more easily at those temperatures as well, including CF and G10.

Best,

Gary

Reply to Discussion

RSS

© 2019   Created by Chris Anderson.   Powered by

Badges  |  Report an Issue  |  Terms of Service