Multiwii Quad Rotor take off support

[weebly]

I'm trying to fly a quad rotor using multiwii board. But It can't be still flied due to unstable takeoff.

As usual two motors are rotating in high speeds(m1,m3) and other two rotate in low speeds(m2,m4). But low speed motors(m2,m4) do not work vary their speeds at same time.

When I decrease pitch m2 keep its speed constant in any position while m4 tries to be stable. When I increase pitch, m2 varies its speed in different positions while m4 remains constant.

When I'm increasing throttle speed to take off (pitch=0) m1,m2,m3 motors vary its speeds and and try to remain stability. But m4 motor is not varying its speed and remain constant. Therefore rotor becomes unstable and difficult to take off.

What should I do?

[waltr]

Did you calibrate the ESCs?
Did you check every thing in the MultiWii config?

[weebly]

Yes I used the default calibrations which comes with open source GUI. Then I used the full code. Nothing edited. What should be the problem here?

[waltr]

Did you calibrate the ESCs?
Google this to learn how.

[weebly]

Yes I calibrated ESC's using the code

#define ESC_CALIB_CANNOT_FLY

This code was used. 1st I uploaded the code and kept 30 seconds and gave time to auto calibrate. Then I commented the above code and again uploaded the code.

But still I have the problem in motors while take off. It cant be kept stable while taking off.

[o_lampe]

You should move this thread to " getting started", there are more readers who can help you.

Here is a quick todo-list, before you try a first flight:

Install a MultiWii-GUI and connect it to your FC
Check your transmitter for correct travel-adjustment (e.g. stick-center has to be 1500 for all channels )
Move sticks and check endpoints. Should be 950? and 1850? at least
Calibrate Acc
Calibrate mag. Go outside to do that. I've seen up to 20° difference, when you do this in a magnetically polluted environment
Configure the AUX-Channels. A good setup for the first flight would be : enabled angle, mag and headadjust.
Don't enable baro on the ground!
Uninstall the props and arm the copter. Check if the motors are running in the right direction
With a GUI connected, check if the motors get the right commands, when you move the sticks
With props installed, hold the copter in one hand ( be careful!) and check, if the copter tries to keep level, when you move it by hand. Do this with 1/4 throttle.
Slowly rise throttle until the copter can hover on it's own and carefully release it from your hand.
If the copter hovers quite stable, you can try your first flight. ( if you have GPS, wait until you have a solid GPS-fix )
When you start it from hand, you can rise throttle slow. Starting from ground you should rise the throttle a bit faster to get out off the "ground-effect ". Otherwise the copter crawls on the floor uncontrollable

Good luck

[weebly]

thnx.I will try and post the result..

[waltr]

The quad I just put together this past weekend had the same problem, front props running faster so quad wanted to tilt backwards.
Re-didACC cal -> still the same.
Re-calibrated all four ESCs using the RX Ch3. Problem fixed, quad lifted off level.

So, do not over look re-calibrating the ESCs.