Problem with tiltrotor tricopter-plane

ArduPlane Plane 3.8
1

Hello,

I have build quadplane - flying wing (2m, 60dm^2) + tricopter with two front tiltrotors
Total weight - 4kg
engines: SunnySky X2814 with APC 11x5,5 - max thurst 3x2330 ~7kg,
Battery - Liion 4s 6p - 18Ah - 120A max countinous,
ESC - Hobbywing 40A (max 50A).

On 20% throttle plane breaks off the ground but its hard to fly higher - like it dont react on throttle position.

What could be issue of this behavior?
Maybe 4s Li-Ion is not enught?

2

If you do not hear the motor rpm increase as throttle going up it might be a calibration problem of the esc , check also in your logs if your throttle pwm output at max is around 2000 if not check your radio setup and do a new radio calibration in Mission Planner.

3

radio and ESC calibrated, also tested in high and intermediade timing. It looks like soft wouldnt let plane take off higher…

4

Are you taking off in Qstabilize mode ?

5

Yes - in Qstabilize mode

6

I’m having a issue with a BlHeli Esc a Hobbywing 35A X Micro .

No way to pull out full power from the motor , max was around 65 - 70% while with a “normal” airplane esc I got full power.

7
  • What’s your motor kV?
  • LiOn battery typically have very low C rating. Based on your info, at best your pack is 6C at best. Wouldn’t surprise me if your setup is pulling 15+C to lift 4kg.

Good luck.

8

motor 1000Kv
Battery have 20A normal current, so total 120A

It can be problem with ESC - I found this on you tube:

I will try to flash them - blheli? simonk? any advice?

9
  • SimonK works for me.
  • Are you sure it’s 20A and not 2.0A or 2000mAh? A car battery is 85A (just for comparison).
  • A quick plug into eCalc shows your setup has 1.4 thrust-weight ratio with 68% throttle to hover at 64amp draw. Have you tried using a LiPo battery instead?

Good luck.

10

Im usiing Li-ion : http://lygte-info.dk/review/batteries2012/Samsung%20INR18650-30Q%203000mAh%20(Pink)%20UK.html

datasheets says 15-22A

In different projects they work well…

Anyway I will try some lipo before flashing…

11

20A is not the “normal” current it is the VERY max current the battery can hold for a little time and if you translate that in C terms , it is just 6,66C of discharge .

But at 20A that battery will become VERY hot and will provide energy just for 6 minutes not the expected 9 minutes. Consider also that with high discharge rate the tension will be quite low.

If you tell me your AUW and the prop diameter I can tell you more

12

It is indeed could be a battery issue. Just for the sake of testing, put in some LiPo (less or equal weight) and do a test with it.

13

I will try on lipo 8Ah 4s tommorow. I will let you know results. Thanks for help!

14

You had right - problem solved. Now for PIDs time… In copter mode there is only P to change? is it correct?