65121 not running well in FOC mode with 10s

Build, Repair & Mod
1

Hey all,

I need some advice from all the FOC gurus here.

I have a 65121 that works great in FOC mode with 15s batteries.
With 10s it’s a completely different story. The motor doesn’t seem to have a lot of power and starts clunking if I pull too much throttle (can’t get on foil because of that issue).
If I switch from FOC to BLDC, the motor has plenty of power on 10s and no clunking.

Here are the FOC motor detection results:

  • Motor Resistance (R): 61.2
  • Motor Inductance (L): 67.24
  • Motor Inductance Difference (Ld -Lq): 46.79

For comparison, I also have a larger 65161 which runs great with 10s and FOC.

t-dub

2

Update:

It seems to work fine now after making the following changes:
1.) Use a different prop with bigger blades (Fliteboard prop). Maybe this helps because I need less RPMs
2.) Change motor resistance value from 61.2 to a lower value (50ish).