Hi all- 

This is my first foray into, well building anything (besides dorm room shelves)... I've got my copter all assembled, but am having a really hard time getting it to take off. I've checked out the troubleshooting page, and re-calibrated my ESCs multiple times, the copter still won't take off, just flips over right away.

I'm using a Q-brain (I fried the PDB when soldering), and from what it sounds like, it sounds like an ESC problem. I just can't figure out how to fix it.. The motors don't appear to beep in the correct sequence when plugged into 4-way hub, so I took out each signal wire and individually swapped them out to calibrate them all via the powered, S3 servo cable. 

I am using a Frsky receiver with a Turnigy 9X. I've read that both channel 1 and 3 are the correct places to plug the Q-brain servo cables into. Another weird thing that is happening that may or may not be related- the motors do not start to spin until I reach 50% on my throttle. 

Any help would a greatly appreciated! It's incredible frustrating to have stumbled through everything else and made it this far and get hung up as soon as the props actually start spinning.


Here's a video that may be able to explain things clearer.

Thanks so much in advance!!!

You need to be a member of diydrones to add comments!

Join diydrones

Email me when people reply –


  • Use trim option in the radio controller and trim it in the opposite direction of its motion...for example: if its flips forward then trim in the backward direction...this way you can adjust he controller and have a flight...and for not starting of the propeller you sud have full throttle pass! What are u using as a flight controller???

    • Don't trim the radio. 

      Setup your flight controller properly and allow it to manage individual channel throttles.

    • What do you mean by full throttle pass? It seems that the zero value has somehow been set to 50% on the TX, as the copter will only start to take off at full throttle. Is this more likely a TX setting or Mission Planner?

      I'm using a Pixhawk. 

      Thanks so much!

  • It doesn't look like you've done a good ESC calibration.. Are you using an APM, have you done this?: https://www.youtube.com/watch?v=gYoknRObfOg

    All the motors should spin up at the same time with throttle.

    • Thanks, I'll try that. I'm using a Pixhawk

This reply was deleted.


Shivchand Jaysaval liked Shivchand Jaysaval's profile
Aug 25