My friends at DIY Drones:
Following the Arducopter online manual, I have finished building my first Arducopter, calibrated my ESCs, initialized it with the configurator, setup the RC, and ran successfully through the Pre-Flight test. As far as I know, I followed all the steps correctly.
In terms of parts and configuration, I have a pretty standard Arudcoputer:
Software: Arducopter_alpha_1.0
ESCs: Turnigy Basic 18A
Motors: KDA20-22L
Front/Back Props: APC 10x4.7 Propellers, lettering facing up
Side Props: APC 10x4.7-P Pushers, lettering facing up
RC: Futaba T10CHG Tx (in airplane mode) & 8-channel Rx.
Frame Arms: aluminum arms from beta kit
Frame center: several thin sheets of perforated aluminum, same size as beta kit
Battery: zippy 2200 3 cell lipo
Total Weight: 967 grams
I just did my first flight test. I arm the motors. Then I push the throttle forward. The front and back props spin proportionally to how far I push the throttle forward. The left and right props don't spin if I push steadily forward, but if I tilt the joystick to the left or right, then they'll come on, but at the same time, the forward and back props go off (even though the throttle is well on). As I move the joystick around, the front/back spin hard or the left/right spin hard, but seldom do they spin together (though sometimes rarely they do). My first question: Is this normal behavior? I guess I assumed all the props would be spinning more-or-less all the time to a greater or lesser degree. I wasn't expecting two props to go off when the other two props go on.
As I do this, even when when I push the throttle all the way on, the arducopter does not lift off. It's not even attempting or struggling to almost lift off. It's working extremely hard at something, but taking off isn't it. As I move the throttle joystick around (or the right joystick also) I can see the motors responding and the unit rocks back and forth, and tries to turn, as it changes the engine speeds, but no lift off at all.
My first thought was that I have the propellers on backwards or something, or the motors are spinning backwards, but I tried to be careful on those points when I assembled it (When I first built it, I did switch the direction of two motors by switching two of the ESC wires so that the motors were turning consistently with the diagram in the manual).
So, I'm not sure what the problem is. If any of this sounds familiar, or if you could help narrow my tests and diagnostics, I would appreciate it. It could be that you'll hear these symptoms and know from experience where I've gone wrong.
At this point, with out any further information, I'm going to start a general diagnostic process to see if I can isolate the problem:
1. When I got to the motor calibration step in the manual, I tried to do that properly, but the beeps are a bit hard to interpret (I come from the robotics world rather than the RC world, so ESCs and this type of brushless motors are new to me).
2. I'll double check all my motor/prop directions to make sure the right ones are CW and CCW, etc. Maybe in my attempts to make sure I got these on right, I did it exactly backwards or something.
Any clues you can provide to help me in my diagnosis of the problem would be much appreciated.
Replies
Mine weigths 1005 grams
Propellers are correctly oriented, EVERYTHING runs perfect, i have double checked everything, propeler orientation, motors direction of spin, ..... .
Holding in manually it responds exactly as expected to changes in attitude...Battery is 3c 2200ma 30c and does not appear to be short of current.. The motors speed respond very well and acordling to the throtle command
I am located in Bogota, Colombia at an altitude of 2680 meters above sea level...... Air is thin here .....
Help would be very much appreciated ???
Yes ArduCopter is a lot easier to fly than helicopters, they are rather different. Helicopters are really unstable by their nature and if you think that flying heli in simulator or in real life is difficult. You are correct.. On beginning it feels rather impossible to fly helicopter (i know, i've been there). You might feel that no matter what you do, your heli crashes immediately and well to be honest. It is like that. When flying helis, you just need to be one step ahead of it's movement always if you are not = crash. But with a lot of practice you can get even helis up and flying really nice.
Then again ArduCopter by it's nature is a lot more stable than helis, it has similar control mechanism than helis but that's it.. Everything else it totally different. When flying ArduCopter in stable mode if something goes wrong just let go your control stick and it level's it self automatically. Heli's don't.. Ok ArduCopter might drift a bit after that but at least it's level.
IF you have some weird flipping problems etc then you might have some other problems too. ArduCopter should not flip on takeoff. You need to make sure that all engines are running before takeoff, they they are not... Do not takeoff.
Yes you should always make a quick takeoff at least to altitude of 0.5 - 1 meters. This is because close to ground you are affected thing called groundeffect. What that is, well there are a lot fancy explanations how that affects but let's put it simple way.. Close to ground you have a lot of turbulence and because of that it's difficult to control your helis/quads etc.
Ok ArduCopter can handle rather well close to ground flying but it also needs some input from pilot so my suggestion is that before you know better of how to control your quads, don't fly too close to ground. You will learn it later...
You also might need to change a lot of your PID settings to make it more stable to fly, this all depends on your frame you use, weights, motors, propellers, esc and it's only you who can find proper settings for them.
Check our WIki pages on how to tune PID to get you started.
I have fixed wiki documentation for puller/pusher propellers. Some manufacturers call pullers as pushers and vise versa so it will be always a bit problematic. But as long as they all blow downwards and motors are spinning correct direction it will be fine.
Correct motor direction as follows: Front/Rear ClockWise, Left/Right CounterClockWise
I was going to mute the sound on the video, but I thought you guys might enjoy hearing the happy/impressed reaction from my ten year old daughter (who has been building this with me) and from my stunned wife (who was secretly pretty sure it would never fly) as we watch our Arducopter's maiden voyage in our backyard. I'm sure you guys have all been there.
You may notice in the video that there are a bunch of wires hanging down from the Arducopter. Those should have been tucked neatly into the unit's lower shelf, and will be from now on.
You'll also notice that the Arducopter is going up and down quite a bit in flight. This is in direct response to my throttle movements. I've never flown an RC aircraft before, of any kind, so I think I was probably over doing the throttle movements. It could be that the throttle is over sensitive, but it's probably more likely operator inexperience/nervousness.
I just want to thank everyone at DIYDrones, and especially Chris and Jani, for sharing all this knowledge and empowering us to build this cool stuff. Working together, we're standing on the shoulders of giants. Well done, guys. :)
Now, my daughter and I are onward and upward with further improvements/refinements.
Flyer-Test-2.m4v
This made a huge, immediate difference. When I touched the throttle I could see right away that it was going to go upward. I did a short test flight, then a medium test flight, then a longer one of about 20-30 seconds. The quad flew beautifully! Very stable. Very responsive and fast. Success! :)
Thank you for all your help on this.
I will post a video in a few minutes.
When it's still on the ground and I first bring up the throttle, some of the motors go on and off, etc., as before, and it looks like it's not going to be stable because various motors are going on and off, but if I ignore that and just give it more throttle and get it up in the air it seemed stable and responsive. Should I be worried about that on/off thing or is that normal when it's still on the ground?
This confuses me. The props are mounted with the lettering up. The motors are spinning in the correct directions (CW for front/back, CCW for left/right). I don't understand why the air is blowing upward instead of downward. I must be missing something very simple here.
It also doesn't explain (as far as I know) why certain motors would be going off/on they way they do.
Flyer-Video-1.m4v
Does it try to get off at all?? If you hold your quad above your head (hold firmly with one hand) and you have all your engines running, if you roll your quad left, right, nose down or nose up does it "fight back" eg. trying to compensate your moves?
How about if you move your aileron/elevator stick. Does quad move right directions accorting your stick movements? If you go 50% throttle or even 100% throttle, does your quad get heavier or lighter?
And you did not paste any snapshots from 'S' when motors are armed and throttle is about at 50%. No need to have battery connected during this test
Did you calibrate the motors manually or with the Configurator?
Regards,
TCIII
do they spin as expected?
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