After a couple of successful autonomous BIXLER flights, I felt I could securely move to the bigger Skywalker, which had it's maiden flight yesterday: APM2, Arduplane 2.66, Skywalker default param, 3DR UBLOX, no airspeed installed though.
Since I realized through some former reading that the calibration of the APM on the field is quite important, I used a bubble level placed on the flat area at the back of the prop (as soon after I puggled the battery)
I then tried flying in manual... perfect! not much trimming needed.
Then move to stabilize...perfect! the plane returns to level and straight flight asa you release the stick. Wow, I'm staring to get very excited... the default APM parameters loaded for this plane (http://code.google.com/p/ardupilot-mega/wiki/ConfigFiles) are great and it really stabilize perfectly well.
I then decide to test Fly By Wire A (since no air-speed installed). And that's when I got into trouble. No more throttle!.... stick down, stick up, nada.... reverting back to stabilize... still no more throttle!...even more surprising, reverting back to manual didn't restore the throttle.........?????
Fortunately the plane was high enough and not too far away, and I was able, not without stalling once, to get it (kind of) back in one piece - a bit of a hard landing on the nose but just a couple of small cracks...
Thanks for any help
PS: can share any tlog file unfortunately - it seems none have been recorded for this specific flight :-\
i am not sure but try recalibrating the throttle by putting the radio control trim for throttle fully down. some ESC's are very sensitive end most PWM value. by lowering the throttle trim you would increase the lower end PWM limit. it happened with me with hobbywing ESC's.
Thanks for the good advice Ravi. I will definitely do the calibration again as it would be a logical explanation. In addition, my ESC is a HOBBY KING 50A, so it might well be the same issue than you...?
BTW, is that the way you calibrate it:
1- put the throttle up
2 - plug the battery
3 - wait for the ESC tones
4 - put the throttle down
5 - disconnect the battery
Is that how you would do ?
yes, that is correct procedure to calibrate. make sure that you when the throttle is up you lower the stick immediately after the first beep. beyond the first beep the ESC goes into prorgamming mode and then you cannot calibrate it.
Hi online experts,
Coming back to you on this annoying problem I'm having, the motor stops when switching to FBWA or RTL..
I did a recalibration of the HK ESK as you suggested Ravi (which was a really good idea in any case), but unfortunately this didn't help my problem. Same motor cut when switching to FBWA, but also when switching to RTL, as you can see in this test
My worry is that I had all this modes successful when the APM was recently on the Bixler2 (with the Bixler default config), but now that I have transfered it on the Skywalker (with the SW default config), I get these annoying problems :-\
I'm thinking that if it was a problem with the ESC, then it either wouldn't work at all, or would only work in MANUAL, but it does work ok in STABILIZE mode (whatever the throttle level is)...
So I tend to think that the SW param file could potentially be the source of the problem. But I guess it has been tested already by others, so I really doubt...
One thing I noticed when I got the plane in my hand after it landed in stabilize mode, I noticed that the APM compensations to my movements were not any more progressive as it's the case usually, they were rather 1 or 0, therefore full down or full up for the ailerons, same for the elevator and I guess the rest... what could it mean ? has the APM gone wild ?
What else, as some famous guy would say ? any idea someone ? I'm really stuck in a dead end...
I'm receiving another ESC in 3-4 weeks (standard HK delay here..), so I will try, although same model...
In the meantime don't hesitate if you have any track...
Thanks in advance guys.
PS: I have the TLOG file, which I'll post shortly
Maybe your throttle channel is reversed?
Thanks for your answer.
Just to clarify: in the Radio Calibration of the Mission Planner, there is a small checkbox for the "reverse" of the throttle. Do you mean that this checkbox should never be checked, unless the APM will work the opposite way as far as the throttle level is concerned?
That could potentially explain my problem, if it was the case. The APM would potentially try to increase the level of throttle under RTL, while effectively deacreasing it...will check that asap.