I am new here and I am from Germany. I am a beginner with Pixhawk, but fly multirotors since 2008.
Pixhawk looks very good to me. Unfortunately it keeps using up my propellers and copter arms.
The last crash from today was when using RTL. So far everything was very good. Loiter was very precise. I then used RTL. It climb up then returned to the take of position. Started descending and then stopped. When I expected it to slowly descend it just turned down motors and droped out of the sky and made a lot of damage. RTL has worked very fine before.
As I had several crashes now for different reasons I don’t dare to fly the system anymore. I think motors should not switch of when flying. After the first installation I had wrong Parameters for P-Rate. After installing Plane and the reinstalling Multirotors I got the right Parameters. That was crash no. 1. When executing Autotune which went fine for 5 minutes ore so it ssuddenly crashed. I had a second crash wih Autotune then. After that the copter went funny when using the Yaw stick several times. A bit later it was OK.
I hope you understand that I have no trust anymore until I know what was wrong.
I hope very much that anybody knows the answer to these problems.
Regards
Derek Belz
Log of last flight enclosed
Hexacopter with Pixhawk and 3DR Compass and GPS
Latest FW
ESC from AFRO Slim Line 20A
Turnigy Multistar 4822-390Kv
1755 CF Props.
Weight 2700 g
I am new here and I am from Germany. I am a beginner with Pixhawk, but fly multirotors since 2008.
Pixhawk looks very good to me. Unfortunately it keeps using up my propellers and copter arms.
The last crash from today was when using RTL. So far everything was very good. Loiter was very precise. I then used RTL. It climb up then returned to the take of position. Started descending and then stopped. When I expected it to slowly descend it just turned down motors and droped out of the sky and made a lot of damage. RTL has worked very fine before.[/quote]
Trying to descend at 40.37 m/s (90 mph, 145kph) will do that.
parameter your value default value
LAND_SPEED 4037.0000 50.0000
That indicates that you are having ESC sync issues, which are generally caused by simonk ESCs on low-kv motors. If you are able to lose sync in autotune, your motors could lose sync at any other time and your whole contraption is unsafe.
First off, ditch those ESCs. SimonK on props larger than ~10" is pointless. I don’t know what ESCs to suggest, perhaps someone else will chime in?
I’ve always wanted to try these on a multicopter: hobbyking.com/hobbyking/sto … ouse_.html
They do active freewheeling, which means they are more efficient at lower throttles than other ESCs. They’re also pretty configurable if you get the programming card. I’ve got a 150A one in my plane.
Regarding your LAND_SPEED, were you ever changing that? Maybe with CH6 tuning? You say it worked before, which means that it wasn’t something that was left in there from the factory or anything. Could’ve accidentally changed it, as well.
Hi,
thanks for your precise answer. I spent all night on the subject and found out what you said is right, 40 m/sec is too much. This happened because of a bug in the mission planner. At least my mission planer is responsible for the crash.
The landing speed was at 30. After a nice and perfect landing we increased the landing speed to 40 cm/sec. The window showed 40.37 cm/sec. When I save and reload afterwards it is 4037 cm/sec. Also under “Full Parameter List” is a similiar problem. If I write there 40.37 it is changed to 4037.
I played a bit with RTL Altitude. Input 5 changes to 4 ???
I would expect the input for landing speed should not allow anything above the default maximum.
Concerning ESCs we have tested them on the ground with fast throttle change and found no problems. On the other hand I think an ESC problem would explain all sorts of problems I had.
I have on the table Blue Series 40A SBEC because I have to change to 5s batteries in order to lift the camera and gimbal. Do you think they could work with my motors? Should I leave the simon k software away and use them originally? I see that HK has a Hobbyking YEP 45A (2~6S) SBEC ?
Edit: I see you are using the full parameter list. I will forward this on to the developer of MP. Meanwhile, please try using APM planner, as it should not do any unit conversions.
I am using Mission Planer. My parameters are flying quite well apart from the wrong landing speed. It is almost impossible for example to adjust the landing speed to 40 cm/sek and that also applies to the Fulle Parameter List. I dont know the difference between Mission Planer and APM planer. If it is better, why not.
I just thought you might be interested in bug reports in order to prevent other people from crashing their copter.
In adition to the above mentioned bug I have found another one.
As I said with the first time installation I got wrong default parameters which made the copter almost unflyable. Rate P for pitch and roll where about 0.085.
A friend today made his first time installation and also had similar values which I have enclosed for you. After installing plane and again installing multirotors he got the right paarameters. Without me telling him he would have had a problem.
I also think now I should use different ESCs. Have you got an answer to my mail from this morning (UTC).
In my version of Mission Planer its different. If I take Land_Speed and put for example 40.0 into the field it saves 400 to pixhawk. It only works properly if you dont use a dot. In most cases of course people would not use a dot here.
I think this is your problem. Please try entering just “40”. Not “40.0”. That parameter is an integer, not a float, so seems like something is getting messed up in the translation.
there is a misunderstanding. Of course I have managed to enter the right number. I have only been trying to tell you that there might be a bug in the software and other people might make the same mistakes I have done.
Everything looks fine with me except that I dont know which ESCs to use in order to avoid sync problems.