FOC vs BLDC Debate

ESK8 Mechanics
21

FOC killed my vesc :frowning:

22

What how? D:

23

Details, please. As far as iā€™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?

1 Like
24

Sensorless, Turnigy 6364, latest revision etc.

FOC just isnā€™t nice to the current revision of vesc I think.

25

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.

26

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 itā€™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 didnā€™t really think FOC will be big, so he made them ā€œfoc-readyā€, but not really ā€œfoc-orientedā€ adds to this conclusion. It seems v6 will be a lot more robust in this regard.

27

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

28

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:

29

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, letā€™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 esk8.de

edit: rode 18 km (~10 miles) and made a quick ā€œtimelapseā€ video (2 hours shooting and editing/publishing) of 3-4 miles track: (https://maps.app.goo.gl/i/wDQSU - back and forth, recommended route if youā€™re in london east / se)

https://www.youtube.com/watch?v=xqS5nSAGw9A

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 hasnā€™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 esk8.de 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

4 Likes
30

Anyone try running FOC with an enertion RSpec setup?

31

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

32

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?

33

alright yall

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

34

want a reliable board that (probably) wonā€™t blow your VESC? BLDC want to be on the bleeding edge and experiment while risking your VESC? FOC

2 Likes
35

option 3: Wait for VESC 6.0?

36

Sounds like he already ordered a 4.xx VESC

37

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

38

Iā€™m more interested on how many messed up their VESC on FOC just because they didnā€™t know what they were doing.

1 Like
39

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

40

Not at all. Iā€™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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