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The rpm control is not working properly

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Joined: 2021-11-02 10:37
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The rpm control is not working properly

Hello, I am not a native English speaker(Korean). Both translator and interpretation are used. Sorry.

And, I am a beginner. We ask for your understanding in advance. thank you.


I am working on a project to make an RC car. 

I bought a 'VESC 6 MkV' and followed the 'Motor Wizard FOC' of the VESC Tool Manuals on the VESC home page to calibrate my motor.

(Motor Wizard FOC link :


Then, to check if my motor is well controlled, I gave the ERPM step input at the bottom left of the VESC Tool.

Two problems arose at this time.


1. The motor accelerates too harshly.

  : I felt a strong force in my hand holding the motor.


2. The motor sometimes seems to lose commutation timing. (although this is my prediction)


To explain the phenomenon in more detail, when this problem occurs,

 -  a high-frequency sound is made

 - the shaft of the motor does not rotate

 - the temperature of the motor increases rapidly, and sometimes smoke is emitted from the motor (at this time, the power is cut off urgently).

 - In addition, a red bar appeared on the left side of the Current bar at the bottom right of the VESC Tool, and reverse current seemed to flow.


The frequency of this problem is

- Occurs briefly (<0.5s) when the motor starts to accelerate and then disappears. or

- Occurs while the motor rotates a few seconds after reaching the desired ERPM. or

- Or when step input is given above a specific ERPM (>10000ERPM).


I expected that the cause of the second phenomenon was that the VESC lost the commutation timing when doing ERPM control

Because of this, more current was sent to reach the desired ERPM (also generating heat in the motor),

and the commutation of the correct timing was not achieved, so the shaft of the motor seemed not to rotate.


Also, when duty cycle control or current control at the bottom left of the VESC Tool is used, neither of the above problems 1 and 2 occur.

In other words, it accelerates smoothly and is controlled as much as i want.


Am I setting the VESC wrong? Probably because I'm a beginner. But I don't know what I did wrong.


*The motors I use are:

1. X-TEAM XTI2430, inrunner , 4-poles, <75g small bldc motor

 :  EDF Inrunner small in 'Setup Motor FOC' of VESC Tool

2. SunnySky X2212-13, Outrunner, 14-poles, <75g small bldc motor, KV 980

:  Mini Outrunner smalll in 'Setup Motor FOC' of VESC Tool

and I used a power supply(SMPS 12V output)


Thanks for reading.