Focbox reset on wheel lock up

Hey guys, i have built a mini e dirt bike with a focbox and sensored 6374 motor but I’m having an issue that is probably very specific to me and I’m wondering if anyone has any idea how to fix it.

Issue is, it being a bike the rear wheel sometimes locks up under braking which I’m ok with however this causes the focbox to reset, with no fault codes showing. Is this some sort of safety feature or some sort of fault that’s not showing up as a code?

Edit: Under braking i mean, when i apply the disc brakes, not the regen braking. IMG_20190317_140139


Elaborate on what you mean by “lock up”. Do you mean it’s applying brakes?


Yes that’s why i said under braking

Are you running sensored or unsensored?

Do you guys read the post lol?

You said the motor is sensored. So are you running in sensored mode? You can run a sensored motor in unsensored, sensored, or hybrid mode.

Also, free advice…


I’m running in hybrid bldc mode

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no one knows? anything? this has literally never happened to anyone?

you’re not really helping your case here champ


Well he’s asking questions that I’ve already stated answers to in my post

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quit the attitude bucko. for the record you did not answer the questions in your original post that he asked. He’s just trying to help, and I’m certain that he knows more than you. if i was @b264 i wouldnt be replying anyway as you don’t deserve it


Am I really reading this? :joy: What an attitude for someone who needs help, damn…


@robthebuilder glad im not the only one seeing it

So it resets when you apply the mechanical disk brake? Its not really a use case on skateboards but there must be others using VESCs on bikes.

We need to see screen captures of all your vesc settings, there may be something with them that can fix the issue.

And how many cells are you using?

I’m guessing some sort of voltage or amp spike that makes the vesc go ohh shit and it shuts down to protect its self. Data logging would make it easier to figure out.

Also make it repeat the issue, then plug it onto the PC without turning it off and check for errors by typing “fault” in terminal. This should reveal the error.

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It should not reset.

If I accelerate and then let it free roll it doesn’t reset nor does it do that if I were to foot brake. Maybe it does, I never tried but I don’t see how a mechanical brake would have any effect on the esc at all. Maybe since it is a dirt bike you are applying the mechanical brake whilst accelerating in which case it would effect the esc since it might overheat this way.

I’m running 12s LiPo so 50.2V fully charged. I’ll get some logs but i don’t think it’s giving me any faults last time i checked.

A voltage spike might be the issue. I’m no expert what so ever but it feels like it might cause a problem if the motor just suddenly stops without a “brake input” to the VESC (focbox).

Maybe there is even some kind of safety function in the VESC in case the motor seizes or if something is blocking the motor from spinning.

If you apply the two brakes at the same time, will the VESC still reset then? I mean the disc-brake and the regen-brake. If there is no problem then, it might be some kind of safety function that can be disabled.

Regen is automatic when i release throttle so it already is braking with both. I think there is some sort of motor stop safety for board riders so the board doesn’t just keep trying to spin the wheels in case you hit something. Wish there was an option somewhere but i don’t see it to disable anything like that.

So the motor brakes when you let go of the “gas”? Mine doesn’t, that’s why I ask. It will regen I know, but it won’t brake. What if you try to actually use both Brakes at the same time?

I thought regen is braking, it’s at -20A for regen, i don’t have anything hooked up to cause the motor to actually brake so it’s disc brake only braking.