Motor surging?!

[malcthom]

Hi
I am new to this. I have a CopterX 450 SE V2 full of replacement Align parts.
I have followed Finless video guides to set up.
Problem I have at present is surging of the motor at 2/3 + throttle.
No surging at less than this.
There does not appear to be anything binding mechanically.
Is this a problem with the ESC?
Thanks

[Bob O]

Battery not fully charged? Low "C" battery? Or the ESCs Low Voltage Cutoff set too high.

You should be using a Li-Po battery that is at least 3S 2100mah 20C.

[Adventurer]

Originally Posted by Bob O

Battery not fully charged? Low "C" battery? Or the ESCs Low Voltage Cutoff set too high.

You should be using a Li-Po battery that is at least 3S 2100mah 20C.

All correct, but rather cryptic.

Some ESCs will warn you of a low voltage condition by "surging" the motor. So either there is a low-voltage condition, or the ESCs low-voltage warning is incorrectly set. This second option would be my first port-of-call on a new bird.

Do you have the ESCs manual, if not, then it's probably down-loadable after some googling. A quick 1st check would be to count the final beeps as the ESC arms. Various ESCs play different tunes, but in this range they all seem to include a cell count. (2, 3 or 4 flat beeps) So for a 450 you should be hearing 3 beeps for a 3 cell battery, if not, then you need the manual to change the cell count setting in the ESC. The number of cells determines what constitutes a "flat" battery, so a too-high cell count in the ESC would fool it into thinking your battery was flat, when it's full.

Check this and report-back.

[malcthom]

Thanks for your replies.
Batteries are appropriate & fully charged, and ESC is setup correctly for 3 cells.
Any other possibilities?