FOC vs BLDC Debate

FOC killed my vesc :frowning:

What how? D:

Details, please. As far as i’m concerned FOC is the more proper way to run motors. Are you sure you have the right VESC revision and firmware version? Also, are motors sensored?

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Sensorless, Turnigy 6364, latest revision etc.

FOC just isn’t nice to the current revision of vesc I think.

I disagree. There seems to be much more stability on bldc on hw4.xx versions of VESCs. FOC has been known to kill lot of them. I just hope the issues are remedied in 6.0.

My bad, I meant that FOC in general is the more proper way. Now I made a little research about current vesc hw rev and found out it’s really not ready for reliably handle FOC on a lot of motors. The fact that when Ben made first revisions of the board, he didn’t really think FOC will be big, so he made them “foc-ready”, but not really “foc-oriented” adds to this conclusion. It seems v6 will be a lot more robust in this regard.

@whitepony I want to try FOC but I’m afraid that it’ll kill my VESC. I hear that switching from BLDC to FOC is risky. How did you do it?

i re-flashed the firmware to have factory settings and then just set up foc. since my last vesc repair it works flawlessly!

p.s.: I just think foc somehow runs cooler under load - it might not resolve your issue generally. for me it was just on the edge I guess - bldc was a little bit too warm and foc is just cool enough to make it up there. guess it could help you a little, but it wont allow you to magically get up any hill without overheating. :wink:

As now I have a backup vesc I upgraded to the latest firmware and switched to FOC. Rode 2 miles with it and it seems all very good so far, not only the board is more silent but the acceleration and braking is much smoother too, let’s see for how long this vesc will last :slight_smile: :upside_down: :slight_smile: :upside_down: (this vesc already has ~150 miles on it with bldc)

setup: 6S - 6374 sensored motor + vesc from

edit: rode 18 km (~10 miles) and made a quick “timelapse” video (2 hours shooting and editing/publishing) of 3-4 miles track: ( - back and forth, recommended route if you’re in london east / se)

the steps to switch to FOC with a similar setup like mine are:

  • flash new firmware (optional but recommended)
  • set battery (cutoff start and end) and motor parameters (motor max), I left battery current limits parameters at their defaults
  • set rpm limit if needed (high kv / high voltage, not in my case)
  • FOC detection process - Measures + Calc CC - Apply/Apply
  • test, run FOC detection process again
  • check that the buggy value hasn’t raised in Advanced (current ramp step should stay around 0.04)
  • configure remote

edit2 - WARNING: FOC may destroy your VESC - I noticed that on a brand new Enertion VESC powering a brand new RSPEC 6374, following the same procedure that works for the VESC and sensored motor, the motor was failing to spin at startup sometimes, I ignored the issue and boom, after 5 min ride time the vesc caught fire - use at your own risk


Anyone try running FOC with an enertion RSpec setup?

I am now, set it up last night and might have a test run today! bench looks fine :slight_smile:

My understanding on why this is, is because FOC has better torque. I have definitely noticed this in my riding FOC, it gets me up hills a little better. Anybody else notice this?

alright yall

if and when I get my VESC :joy: from @torqueboards, should I go FOC or BLDC? FOC seems veeerryy promising but unreliable.

want a reliable board that (probably) won’t blow your VESC? BLDC want to be on the bleeding edge and experiment while risking your VESC? FOC


option 3: Wait for VESC 6.0?

Sounds like he already ordered a 4.xx VESC

I wonder how many people have used foc and not had a problem with it.

I’m more interested on how many messed up their VESC on FOC just because they didn’t know what they were doing.

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Are you saying that when used properly, the vesc should be completely fine on foc?

Not at all. I’m just interested in seeing the % of people who have blown VESCs from normal operation vs those who configured it wrong.

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