VESC 4 BLDC motor twitching

Who can explain why the engine twitching when the BLDC mode on this video? It can be fixed?

sensorless engine so cooking at the demarage …

Do not understand a little bit. What you mean?

if your engine does not have a sensor then it is normal that you are a twitching …

These twitches will not spoil the motor or VESC?

The difference in the use of the sensor and the sensorless motor only in jerking? The maximum torque, the maximum speed will be unchanged?

Essentially yes. A VESC can run Motors in BLDC or FOC mode. BLDC is the regular mode every R/C ESC uses, FOC is a bit more sophisticated and reducing the jerking in sensorless mode quite abit, but it’s hard to run on high-kv motors and 4.12 regular VESCs.

Sensors are only really implemented in FOC mode, a buddy of mine uses sensors, regular HW4.12 and BLDC on his mountainboard and it still isn’t as smooth as my VESC 6 FOC Sensor setup.

If you want to run FOC successfully, go with low kv motors and at least a Focbox, esk8 controller or similar VESC that is abit upgraded. Also look into stewiis ESCape, bimmers B-Box or Trampas VESC6 for best performance.


Very good summary @Der6FingerJo , you said everything.

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I have 192kv and VESC 4.12 from DIY. Is it safe to use FOC mod with 12s battery?


That will cook your vescs

If limit the voltage to 10s?

Still no, diys vescs can’t handle foc

As @pat.speed said, i wouldn’t risk it either. Options that come to my mind are:

  • switch motor from star to delta connection to reduce kv (i have never done this, you will have to read up on this)
  • get lower kv motors, 130kv and less
  • use a VESC6 based ESC, i don’t think any 4.xx hardware would handle 192kv on 12S with FOC
  • install sensors and have at least a bit better bldc until vedder implements it proper (again, never done this myself)
  • switch to 10S but still need a lower kv motor

Personally i would go with a VESC 6 derivative right now (or the trampa one if you can afford that, lol) as it seems to be bulletproof so far.

Would also be interesting what kind of board you want to build, mountainboard like in @Rich’s video or something else?

Spot on. I’ve never personally heard about the kV needing to be low. All I know is focboxs can handle 12s and 190kv. Some even push to 13s but that is right on the limit

I’m not 100% sure about the kv thing, i just know from @Rich that his 136kv motors from trampa worked ok with stock 4.12 VESC FOC on 10S so we thought kv (more eRPM) might play a role in it. Could also be that i underestimate the Focbox, never personally used one :smile:

Hmm that’s interesting I have only ever heard of a small few people that have had foc work reliably on Vesc 4

I can only tell that i fried my stock 4.12 VESC DRV on FOC after maybe 5 kilometers and a hard bump (the electronic box never touched anything, just a semi high curb i didn’t see coming). It was with 10S and 168kv motor, can’t tell if it was because of FOC or because of the bump.

Seems to be a gamble with 4.xx hardware.

That’s why i got VESC 6 for my mountainboard, no worries and awesome startup performance.


I want MTB Trampa

In this case i personally think that 192kv is a bit high on 12S, common gearing options range from 1:4 to 1:5 and even with 1:5 gearing your top speed would be ~40mph~60km/h, assuming you use 8" tires.

Maybe think about changing motors to 150kv or less.

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Holla - holla wait, wait a second. This description have some right and wrong to it. Both BLDC and FOC mode can run sensored and sensorless. VESC doesn’t prefer lower kv motor over higher kv motor and it works well for any of them despite what it’s being used for (drone / rc / esk8) as long as it being used for brushless motor. FOC mode is known for silent and abit more torque compared to BLDC, thats correct, but doesn’t necessarily means that BLDC is worst than FOC and or FOC is burning up VESC. This is untrue, otherwise why most of us runs FOC mode.

There are however some conceptions about bad VESC and bad VESC suppliers, but it doesnt mean it applies to all VESC. I have VESC 4.12 running FOC for 3 years already, works awesome. I got one fail VESC from enertion, one of the very first batch. It even burns from BLDC mode, so it have nothing to do with FOC / BLDC.

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I think we need to make the right setting and will not fry