I tried to create a really powerful quad with HK components and an APM 2.5. It looks like I have created an unflyable monster:
The first flight attempts were a disaster. Upon just touching the throttle it jumped in the air and flipped on its back faster than I could react. It wasn't damaged, so I tried again as slow as possible correcting pitch/roll tendencies before take off. But as soon as it is in the air it's uncontrollable because it's reacting very very fast. It just takes 1/8 throttle to take off. After 3 take off flips it was damaged and I had to stop.
I have calibrated the ESCs and everything is basically working as it should (rotation direction, roll/pitch/yaw etc.). What I noticed was, that one prop was accelerating slower to the idle rotation speed after arming than the others.
Here is my setup:
- Frame: Turnigy H.A.L. (Heavy Aerial Lift) Quadcopter Frame 585mm
- Engines: 4x Turnigy Multistar 4830-420Kv 22Pole Multi-Rotor Outrunner
- ESC: 4x TURNIGY Plush 40amp Speed Controller
- Batteries: 4x 6S 2200mAh
- Props: 12x6 (for now)
My guess is, that the stock PID values are wrong for such a setup. I could also increase the distance between the motors by using the booms from the Hexa HAL Frame.
Any guess what could be wrong, or what a conservative PID setup would look like?
Thanks,
Erik
Replies
Very good!
HERE is how to obtain and analyze the logs. There is a very good video down the page.
-=Doug
Congratulations on getting to this point, now the real work/fun begins.
1) Make/rig some form of tether mechanism to allow about 16 inches/ 35 cm of vertical space. I used two lengths of cord, one on each opposite leg, tied to a heavy item. The idea is to prevent an out-of-control event but allow some vertical lift for low hovering.
2) Confirm your configurations:
a)Frame type loaded into APM via MP
b)Radio calibrations
c)Motor wiring/positions via a CLI command test found HERE.
3) Find and post your tlog here. It will tell us your parameters and give us a picture of the flight event.
4) Confirm your radio is in ACRO (airplane) mode, not HELI.(What radio TX are you using?)
I do not think your arm length, motor selection, props, etc are the problem.
This type condition usually results in a configuration issue of another kind.
Do not mess with your PIDs, yet.
Let us know...
-=Doug