Hi guys, its me again.
Yesterday evening I sat down to repair my old big tricopter (I flew my recently built mini-tri with the same motor/ESC/prop combo the last few weeks) with a new servo and new KK2 HC as a few parts of the big tri broke in a crash because the old KK2 broke mid-flight (simply fell down lika a rock mid-flight).
Today, I went flying with the new-old build and had weird problems:
The tail servo (TGY-211DMH) does not always work like I am used to. Sometimes it just stays in center (even when I bang the stick from side to side) and the copter turns around as if there were no servo. Then most of the time a second or two later, it realises that I was telling it to go in the other direction and then abruptly does just that. Sometimes it is working normally for 20 seconds aswell.
First I thought that my tilting mechanism (I had to redo that too after the crash) had too much friction, so I went and solved that. Now the servo can move rather freely and I bench-tested that aswell with success (I even turned up the motor with a prop on and tried the servo movement, the servo should be strong enough and is working).
It shouldn't be the KK2 board, as it works seemlessly on my mini-tri (exact same settings; the small copter wobbles a bit, but thats an PID issue). The transmitter sends the data correctly (mini-tri works and I checked again via KK2 reciever test). It also shouldn't be a bad connection between servo and KK2, as I've tested the servo many times now (with the same cable that goes into the KK2). Im running a 5A UBEC to power reciever, KK2 and servo. The UBEC worked with the old servos, so it shouldn't be the problem, too (the old servos were digital-metal geared too like this one).
So heres my results:
- servo works when bench testing
- rudder input gets into KK2 cleanly (tested with small tri + reciever test menu)
- KK2 works with small tri
- UBEC worked with old servos and the KK2 and reciever don't brown-out or something when the servo doesn't work
- copter shows weird rudder behaviour in flight as it sometimes accepts rudder input, sometimes it doesn't (for a few seconds)
I now pretty much ran out of ideas and I don't want to take the thing apart without knowing where to search.
I really thought that I figured everything out about these copters and knew how they worked. But at the moment, it doesn't work so great. Even the PID tuning of my small tri doesn't go as smoothly as they say but that's maybe because of my odd setup with big motors/props and small frame that is making it hard to adjust.
Sorry for the long post, but I want to give as much information as possible, so your suggestions can be as helpful as possible and I don't waste peoples time requiring them to suggest things I already done.
Thanks in advance for your thoughts.
-1387
Yesterday evening I sat down to repair my old big tricopter (I flew my recently built mini-tri with the same motor/ESC/prop combo the last few weeks) with a new servo and new KK2 HC as a few parts of the big tri broke in a crash because the old KK2 broke mid-flight (simply fell down lika a rock mid-flight).
Today, I went flying with the new-old build and had weird problems:
The tail servo (TGY-211DMH) does not always work like I am used to. Sometimes it just stays in center (even when I bang the stick from side to side) and the copter turns around as if there were no servo. Then most of the time a second or two later, it realises that I was telling it to go in the other direction and then abruptly does just that. Sometimes it is working normally for 20 seconds aswell.
First I thought that my tilting mechanism (I had to redo that too after the crash) had too much friction, so I went and solved that. Now the servo can move rather freely and I bench-tested that aswell with success (I even turned up the motor with a prop on and tried the servo movement, the servo should be strong enough and is working).
It shouldn't be the KK2 board, as it works seemlessly on my mini-tri (exact same settings; the small copter wobbles a bit, but thats an PID issue). The transmitter sends the data correctly (mini-tri works and I checked again via KK2 reciever test). It also shouldn't be a bad connection between servo and KK2, as I've tested the servo many times now (with the same cable that goes into the KK2). Im running a 5A UBEC to power reciever, KK2 and servo. The UBEC worked with the old servos, so it shouldn't be the problem, too (the old servos were digital-metal geared too like this one).
So heres my results:
- servo works when bench testing
- rudder input gets into KK2 cleanly (tested with small tri + reciever test menu)
- KK2 works with small tri
- UBEC worked with old servos and the KK2 and reciever don't brown-out or something when the servo doesn't work
- copter shows weird rudder behaviour in flight as it sometimes accepts rudder input, sometimes it doesn't (for a few seconds)
I now pretty much ran out of ideas and I don't want to take the thing apart without knowing where to search.
I really thought that I figured everything out about these copters and knew how they worked. But at the moment, it doesn't work so great. Even the PID tuning of my small tri doesn't go as smoothly as they say but that's maybe because of my odd setup with big motors/props and small frame that is making it hard to adjust.
Sorry for the long post, but I want to give as much information as possible, so your suggestions can be as helpful as possible and I don't waste peoples time requiring them to suggest things I already done.
Thanks in advance for your thoughts.
-1387
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