DJI F550 lift issues

[fluffyhead69]

Hi all.

I am very new to this so please be patient!

I recently bought an f550 hex off ebay and have spent the last 2 weeks assembling it and getting it ready. It was a used setup and was working fine with no issues before,

I bought it with no battery and radio so have since bought a 8000mah 4s battery and a spektrum dx7.

I am still sorting out a few bugs with the dx7 but have it setup in atti mode so far so i am able to atleast test the unit before going any further with setting up the dx7.

Aaaaaaanyway. i fully charged the battery tonight after just getting my charger and took it out for a quick test flight. I am only getting about 2ft off the ground before it drops back down again and kinda "bounces" up and down at full throtte. wont take off at all with any less than full throttle. Its running 10" props and they are all spinning the way they should be. for the 5 seconds or so i can get it airbourne it handles as it should do but i just cant seem to keep it in the air and this is before the camera and gimbal!

Any ideas how to sort it?

[Hands0n]

What FC are you using on the f550?  Is it a Naza M V2? If so, something to check is that the FC is firmly adhered to the multi-rotor. It mustn';t be able to move, and should be stuck down with double-sided sticky foam material, as near as to the original part as possible.

What KV are the motors and ESC? And are you happy that the LiPo is fully charged on all cells - the charger should be able to display what each of the four cells have in them after charge.

[fluffyhead69]

dji 2212/920kv motors with standard (as far as i know) esc
Naza M lite and sticks are calibrated and its fully stuck down no wiggle room at all.
Battery fully balance charged and tested with battery timer

[flybywire]

Assuming it is setup correctly, it could be the low voltage protection set incorrectly, i.e wrong cell count etc

[fluffyhead69]

Ill take a look at that, thanks

[Friskle]

Does sound like the wrong setting in the Low Voltage warning.