Focbox in FOC mode

Hey guys,

When I first tried FOC I immediately fried my torqueboards vesc, so I got myself a Focbox from enertion. Been riding with it for a few months and havent had any issues so far. I’d like to keep it that way. But the FOC mode just seems soo much nicer that I can’t stop thinking about it. Two questions:

  1. The sensor cable on my motor ripped off a long time ago. Can I run FOC sensorless? (side question: Could I short my motor because the cable ripped off?)

  2. Is it OK to run FOC on the enertion vesc or am I likely to fry it as well?

And as always: Thanks a bunch guys

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Yes and Yes.

It wouldn’t be called the FOCbox if it couldn’t handle FOC :wink:

  1. Yes, and probably not, but you should probably secure the ripped leads.

  2. Of course, it’s the FOC box, just make sure you set it up right and do not apply more throttle if the motor doesn’t move or acts weird, this is how people blow their VESCs.

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1: I ride Foc on a focbox sensorless. 2: I have ride ± 50km with the Focbox on foc and it works fine, its very silent on low speed. The speed top is lower than BLDC but there are solutions for (gears)

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Thats exactly how i blew my VESC!!

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I cant see them anymore. Can you give me a rundown on how to open it up?

What motor do you have?


Your motor should have a circlip (google if you’re not familiar with them) on the shaft near the base. Use circlip pliers to take them off (don’t widen them too much or you wont be able to put it back on, or break them). Take out any washers under the circlip. Pull and separate the rotor can from the stator and base plate, you’ll need a bit of force to get it out since they’re strong magnets. From there you should be able to see the sensor PCB and desolder the leads.

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Seems daunting, that would also mean id have to take off the motor pulley again and thats always such a ***** :smiley: How likely am I to short my motor?

Well there should be no electricity flowing through the leads since they’re not plugged in anyway, you should be fine, it’s just not elegant.


Ok I’ll be trying FOC mode soon then and let you guys know how it went.

Any great tutorials to recommend?

Just don`t upgrade your focbox to the new vesc-tool fw. Then your focbox is not a focbox anymore. Hope they fix the problem soon…

no worries, i’ll just leave it as it is

You can always just downgrade it again.

this a good tutorial? Anything else i might need to watch out for?

I fried a VESC-X (FocBox) with maybe a mile of testing usage. Not sure what happened but one got a fault and the other didn’t with same setting over split ppm. Scared of FOC now, not even because of the cost to repair or replace but the potential danger of failure during an actual ride

oh man thats scaring me too now haha

i was gonna do it tomorrow morning

Well, double check everything before you go test riding. Check for possible motor wire shorts, strippings and what not. Only when you’re 100% confident go at it. Helmet is obligatory. I was not afraid of FOC, if you do everything right in BLDC tool (conservative parameters with some help of mathematics) and get the motors to spin and everything sounds right when triggered-it’s miles better than bldc imho.

I had my first test ride today with my dual 6355 190kV sensored with Focboxes in FOC mode over can bus. Well, that’s it, I’m done searching and wondering. It’s brutally beautiful to ride, silent, pulls like a motherf****r and brakes like a sportscar.

If somebody wants more performance from their single drive, just don’t stress the components even more with OC parameters in BLDC tool. Double the drive. It’s unbelievable.


What settings did you have? I ran FOC on my Torqueboards VESC “without any issues”…