Now I want to try FOC, but i’d be so sad to blow a $170 VESC 
I wan’t to use FOC too but what happens to the VESC when it fries, is it completly destroyed, repairable, what the fuck happens there?
Usually DRV chip fries
If u know what ur doing, I don’t, u can repair them and it seems not too hard. It’s worth the risk. I don’t hear of many people having problems
gave it another spin and Im really so happy with FOC right now. it feels smoother than BLDC and the silence, especially at startup and low speed is giving the whole board a very natural raw manual longboard feel. like eating something that looks delicious - it just adds to the experience.
couldnt be happier right now, first thing I do when my vanguard is finally finished: update my tesseract c18 modded vesc with 2.18 fresh and set up foc! 
must say, I always had trouble with nunchuck & FOC combo, so it always left a sour taste whenever I tried foc in the past. now with the 2.4Ghz mini remote, its all working just perfect.
7 Likes
Now I want to use FOC too 
Did you ever figure out the bench throttling issue?
nope, its still like that - I stopped worrying after it ran fine on the road.
rew, one of the vedder.se experts, commented on it though:
when you run unloaded, and have “current control” mode, whether you set 10% max current or 99% of max current the motor should spin up to its maximum RPM and then the VESC should see “max PWM reached” and reduce the internal setpoint until things stabilize.
Your observations indicate that with a bigger current-setpoint the behaviour of the limiting is slightly different. I wouldn’t worry about it. If 10% throttle reaches “max RPM” then something is already wrong… (you need a higher battery voltage, a higher Kv motor, or the load has gone missing(*).)
I currently run FOC with my repaired VESC 4.10 on 12S with SK3 149kv Motor and have no problems at all. If i get problems i will Report back. But now i can drive from stand still with no cogging and “ninja mode”. It is just awesome!
1 Like
today I did a max range check on my board and I was actually disappointed. for now I would call the “efficiency” of FOC vs. BLDC pretty much a marginal effect or myth. of course there are more factors than the commutation mode involved - I got the same battery, same wheels, same bearings with a different motor and FOC vs. BLDC. my tesseract with BLDC and 190KV 6355 rspecc managed 39km max range while the vanguard with SK6374 and FOC managed 32km. I rode it hard, carved until the wheels slipped, but thats pretty much what I did with the tesseract too. 
ah well, Ill figure it out - next is a max range check with BLDC I think to rule out the commutation mode.
made a quick video of 50A accelerating and -16A braking of the SK6374 with my german FOC vesc. its interesting, cause its only really ninja-silent when its slow and from mid-speed onwards to the max its nearly as loud as bldc. not sure if its simply the sound the motor makes or if the sound can be attributed to the driving ESC?
and no, I didnt fart in the end 
1 Like
Observed the same thing, when I played with FOC for one day and then while switching back to BLDC it fu**ed up two of my VESCs. Silent when going slow, but as loud as BLDC near top speed, which is noticeably slower tho.
yea, think elkick has established that switching between FOC and BLDC is probably not a good idea. when I try BLDC with this setup, Ill flash the firmware 2.18 again to have a factory new VESC. 
1 Like
I’m still unsure if switching between FOC and BLDC causes problems as I’ve been doing that at least 2-3 times a month since January on both single and dual @chaka VESCs. FOC Ninja silence from startup to top speed is constant on hub motors and “feels” more efficient although I don’t have numbers to back that up. For the amount of time I’ve spent riding on both settings, that “natural” feeling FOC gives is hard to turn down. It may be that FOC is best suited for hubs and BLDC for belt drives. Maybe someone who has both setups can provide some data.
Does FOC provide a natural feel even for sensored motor setups? I suspect the failures switching between FOC and BLDC are due to legacy settings that haven’t been reset from the previous mode. I wonder if re flashing the firmware would prevent these issues.
NIce tip! Thanks!
It’s not a FOC specific question because I hear that you can put the same amount of current to the motor with bldc but what motor current are you running the vesc at? I’m at 60 and read 50 is the max endorsed safe current but people are doing up to 90. If ever there was an important variable on the vesc in terms of putting out power and protecting the motor and vesc this seems the one
I got all currents to specifications, i.e. 6374 168KV @ 70A and vesc battery current max at 50A. didnt feel like blowing stuff up again! 
1 Like
Ok 70 to the motor. I hear the other side from the battery isn’t a concern except to protect the battery. Where’d you come up with the 70 number?
Do u have it heatsinked or kept cool somehow? Does it get hot? I don’t want to blow stuff up either! Did u fix it or get another?
70A is just the sk3 6374 168KV specifications!
I’m mor worried about the esc and trying to find if the amp limit is solely heat related. Guy on vedders site does 90 limit but Rew the vesc expert says 50 recommended.