Hey guys...I put together a 3DR quad (10" props, 850Kv motors) 2.9.1 firmware and after several catastrophic crashes I am sort of getting the hang of it.
This is my very first experience with anything R/C so I realize that most of the trouble that I'm experiencing is probably pilot error, but I seem to be forever chasing my quad around with the sticks. I started with a 4S 5000mah battery and started playing with tuning via CH6_RATE_KP. At first, I followed the guide and based on what I have read since I'm using a 4S I should need to tune down from the default (0.1450), but down doesn't really seem to help the wandering quad. If I tune it upwards, it seems to help - I still have to chase it around with the roll/pitch a bit, but it feels like I'm having fewer over-corrections with the rate_p sitting at around 0.2100. I am not seeing any oscillation, but I'm terrified to take it any higher.
Today's session was in very light winds. The quad seems to remain quite level. It does seem to yaw to the right a little. It also seems to have a tendency to descend quite a bit even with the throttle staying in the same position. The quad is equipped with a sonar and it seems to be working.
Today, I decided to try it with a 3S battery (2200mah) and am seeing almost identical results. I have to take rate_p quite a bit higher than the default before I start to feel like I have any control over it. Should I just keep increasing the rate_p or should I be looking for something else?
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Thanks everyone for the suggestions, I really appreciate the attempts at help. I've got it dialed in now to where it's pretty tight. Now that I have the confidence to take it a little higher it performs quite well once I get it out of its own rotor wash. This was done mostly via tuning and paying close attention to how the battery is centered.
Hi Will. This might be a long shot but take a look at this thread I started this morning. After i posted the pic, user Jim Kahl spotted that one of my props wasn't correct which led me to recognize that I had wired one of the motors the wrong way after my last crash but i had put a prop on it that allowed it to have lift. Your description of "chasing my quad around with the sticks" is very much what mine felt like. I know it's a long shot but hopefully it helps.
http://diydrones.com/forum/topics/arducopter-2-9-released?commentId...
There are a few things to look at:
- ensure that you have calibrated all of your ESC's, either through the automatic method or the manual one, the manual one has worked best for me
- try running the level command from the CLI, I have had much better luck doing this than through the GUI
- in a completely wind free environment (in doors in a gym or something is best) start your copter in auto trim mode and fly it for 25 seconds or so as flat and stable as you can, and then land and disarm your motors...this will automatically trim out your copter to adjust for CG and various other things
I am having the same problem with the little yaw to the right, and I was thinking that my frame could be out of shape.
I had a crash last week and broke 2 motor mounts, but I plan not to fix it yet and wait for some CF tubes and plates that I ordered from hobbyking to rebuild the frame.
So, will see what happens.
I am new to the multicopter myself but I had a similar problem myself. I realigned my frame and motors and tried it again it was 100% improvement with default settings. My motors were leaning outboard a slight amount I used small washers to correct this. My frame has round arms which is more of a problem for alignment than your square arms. Motors are 1000kv and battery is 3s 4000 frame is 680 atg quad. After adjusting the alignment of frame and motors I went back and recalibrated. First flight was almost perfact, came up about 4 feet with only throttle. Before I did not have enough hands to control it. Get it level and square in assembly and it should fly that way. I should not leave out balance of props and also CG. Make shure that nothing is interfering with your sensors. Bring up your sensors on graph and throttle up to see if any readings are going crazy.