Electrical Problems

Build, Repair & Mod
1

Dear all,

I’m having some problems with me set up and wondering if anyone can be so kind as to help me

MY SETUP:

  • ESC: Flipsky FSESC 75100
  • Motor: Flipsky 65121
  • Battery: 2x 6S LiPo in series (12S, 44.4V nominal)
  • Remote: Flipsky VX3
  • Application: Efoil build

THE PROBLEM:
The motor does not spin when the trigger is pulled. No current spike is visible in VESC Tool when throttle is applied, suggesting the ESC is not outputting power to the motor.

WHAT I HAVE TRIED:

  • Full FOC motor detection completed successfully
  • Motor parameters detected: R=4.4mΩ, L=67µH, Flux Linkage=14.4mWb
  • Confirmed Sensor Mode = Sensorless
  • Confirmed App to Use = UART
  • VX3 remote paired and showing live telemetry (battery and ESC temp visible on remote screen)
  • Throttle signal confirmed at 96.9% in VESC Tool when trigger pulled
  • Phase wires resoldered
  • No fault codes registered (confirmed via terminal faults command)
  • foc_openloop commands accepted by ESC but motor does not respond
  • Current does not spike when any motor command is sent
  • conf_store run multiple times but settings do not appear to save properly

MY CONCERN:
The ESC may have suffered damage to the output stage (MOSFETs) during initial testing when the motor was overheating due to a bad phase wire connection. The ESC accepts all commands and connects fine but produces no output to the motor.

Could you please tell me what my best steps going forward are and if there is anything I can do.

if someone is willing to come to Oxford and get on the computer and sort this out will happily pay for their time.

I am based in the UK (Oxford). Please let me know what information or evidence you need from me.

Thank you for your help.

Kind regards

2

Are you sure the UART is connected correctly?
I am asking because the TX and RX cables on the connectors sometimes need to be switched. I have the VX3 and the 75100 from Makerspace. Makerspace has inverted positions of TX and RX pins compared to Flipsky. I was also wondering why the motor does not spin up.

EDIT: sorry just reading that you are receiving the throttle signal in the VESC. In that case I have no idea. But I used Claude to resolve all my issues with the VESC by sending screenshots from the configs and checking the wires.

3

Repeat detection, if it spins there, hardware issue is out.

For VX3 I had to select “current no reverse” or “duty cycle no reverse” option to get it spinning.