I'm having a real boring issue with the hexacopter starts beeping and warning for low voltage as soon as I take off.
It doesn't warn when I take off without the camera gimbal attached.
My spec is:
Pixhawk with 3DR power module
Tarot 680 Pro
6x Sunnysky V3508 700kV
13 inch props
DSLR Gimbal with SToRM32
2x Multistar 5200mAh 4S 10C
I'm having the two batteries wired in parallel and that should add up to 20C discharge rate=able to deliver 5.2*20=104Amps.
Surely, my hexacopter can't draw this much and cause the batteries to drop so much in voltage?? Please help!
The voltage
The current
Replies
That is truly a great post from the user Fastredrover! But since I suspect that the final weight after the arm extensions will land on almost 5KG I'm wondering if his exact setup won't suffice.
It is such a big jungle choosing the optimal motors and prop size.
Yes, it is a jungle, but there are some guide posts along the trail..
First is your AUW, and second is the prop size, and the third is the battery.
If we use 5 Kilos and divide by 6 motors we get 833.3, so we can look for motor and prop combinations that use 6S batteries and 15" props that will give us between 850 and 900 grams of thrust at the lowest possible current.
A Sunny Sky 4010 450kv will do that, as will the Sunny Sky 4010 375Kv, the X4110S 460Kv, the X4110S 400Kv, and the X4110S 340Kv.
The things you need to consider are the Efficiency or Grams/Watt number (Bigger is better), and cost.
Well, the Attopilot 180A has arrived and I have replaced the Hobbyking Power module(but kept it as BEC source). Now with the Attopilot doing the readings there's the same f**king problem! Excuse my language but I'm just so sick and tired of this problem, and especially after wasting 30usd on an overpriced little chip.
This is insane!!!
The current
The voltage(starting off at 16,2V)
The throttle
I got a new Power Module back from Hobbyking and still the same issues. I'll try and calibrate the voltage after I charged the batteries.
I know for a fact that other people have this problem and that more of you will encounter it. Here is a link where big names like Marco Robustini and Rob Lefebre is discussing if Marco's PM is faulty or not. I can confirm that it wasn't faulty, there is a greater problem lying behind it all, since I have it on to Power Modules as well.
Marco Robustini PM voltage drop
Just out of curiosity, what is the aircraft All Up Weight (with every thing installed)?
I'm running a very similar setup, except I'm using Multistar Elite 4006 740Kv motors, Hobbywing X-Rotor 40A ESCs, 1344 wood props, 2 axis gimbal, an SJ400 clone camera, and retracts.
The AUW is 3752 grams, motor/prop grams/watt is 8, hover current is around 30 Amps (5A per motor), and flight times run 18 minutes and change...
The AUW of my Tarot 680PRO is 4.8KG but that is with a huge gimbal mounted with DSLR camera on.
I ran the numbers, and you should be getting around 10 minutes of flight time with a 20% capacity reserve (80% used)..
Based on you log, current draw looks about right...
Are you sure the batteries are good and fully charged? 4S packs should be in the 16.8 range (4.2 x 4), and your graph shows it starting out at 15....
http://diydrones.com/xn/detail/705844:Comment:2118504
-
3
-
4
-
5
-
6
-
7
of 8 Next