Little FOCer! 84V 5kW VESC-Based Controller

Oh…and i really would appreciate a recommendation whom i may contact for some proper vesc tuning specifically Fieldweakening related. I use the board daily but the feature has some remarkable side-effects. I do not know folks that use it and also push the limits so it needs some brainpicking and finetuning.
(And i REALLY do not want to join Fecesbook for it, under no condition;)


This was temporary or all the time? Did you enable IMU data? It’s a separate button to enable on the VESC tool.

What entity did you buy this unit from? Customwheel or Makerspev? That will help me direct you to who can help.

@surfdado has done a lot to develop the balance app and figure out the settings for a LFOC to work well in a OW type application. Check out his content

I get it. There’s a reason i’m not on it either.


I ride OW vesc for almost 1.5 years now;) First Raiden, now Focer. This is literally the only time i had this. I did not change any setting, was just about to leave for a routine commute. Used several times today after the occurrence and cannot reproduce.

Imu ACC data was working, just the orientation was frozen. All the time until rebooted the board as it could not be ridden.

The Lfoc3 belongs to Flux. Im borrowing it since my lfoc3 will go to you for a canbus repair. Looking to get a 2nd once back in stock;)

Im in contact with Surf, will check with him again. If you know any others that do advanced tuning with OW type please let me know. And thanks for your fast replies!!


Was the hardware particularly hot by chance during the time th IMU issue happened?

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No. Board was switched on 1-2 minutes before, temp indicated around 30deg C, a bit higher than ambient.

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Ok. Well let me know if that ever happens again. I have not heard of such a glitch

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I just had my recently installed unit fail. No lights and I think the mcu was shot but I very very stupidly sent 17v in the 3.3v rail trying to check that… Classic

I guess if the next unit fails the same way after a curb drop I’ll probably reconsider using this setup.

Wondering if there is any limits I should have set like ERPM or something. Battery was at 80V.

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Can you describe the situation in which it failed in a little more detail? What’s a curb drop? Does it involve a situation where the motor is spinning really fast then all of a sudden is brought to a halt? Is your system using a BMS? If so, does it cutoff in response to overvoltage? I generally need this amount of detail and more to really understand what’s going on. Feel free to take it to PM

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Yes pretty much but since this is only a curb drop the erpm could not have been super high. A reminder this motor is the unique transverse flux type, so it probably exaggerates voltage spikes in this scenario.

No BMS no fuses. Lots of connectors due to modular battery so that doesn’t help.

Made perfect sense to me that it fried itself and not a bad connection type thing. Unfortunately I was wayyy too tired to properly diagnose and ruined a chance to find out.

Maybe I’ll PM in a bit about if the unit I sent 17V down the 3.3V rail is worth fixing.

Just curious if anyone would be able to help prevent this from a FW / software standpoint as I can’t change much about the hardware/wiring or at least don’t plan to for the next unit that I just ordered.

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Oh yeah. That thing is crazy… Very well could have exaggerated BEMF stuff.

So it was unresponsive before pumping 17V to the 3.3V rail right? Most likely the protection diode on the 3.3V rail is burned out an shorted from the 17V exposure. That diode can be replaced but then we still gotta see what burned out from the curb drop.

I would set the over-voltage threshold as low as you can with out it being annoying. So I think 95V is default but try something like 87V. You need to give it enough margin to not trigger on normal regen braking but then trigger with enough time for the controller to actually respond with a preventative action before damage happens. FW6.0 is also supposed to have faster OV response.

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Sorry to chime in here. I’m using a 20s setup as well and you would be surprised how high the erpm gets during (reasonable) curbdrops or bonks. It spins to max ERPM almost instantly and the landings are eh…still freaking me out, especially high bonks. This really needs a cure, just none yet afaik.


Update: The v3.1 units have arrived to me in the states and are almost to Customwheel in Europe. Seems like customs takes longer in the Netherlands.

I’m running through quality checks. So far so good!


Waiting for months.
Then I see €460 for the kit… Gulp.
Page history:
v1: $150, Kit: $305
v3: €270, Kit: €350
v3.1: €325, Kit: €460
Wish my salary was increased 20%, (or 30%+ for the kit) in few months.
With the shipping costs €500+.
No more comments.

Yep. Things have gone up like everything else in the world. The MCU alone quadrupled in price since COVID hit. The chip shortage cause many semiconductors to go up in price. I’m still working to bring the cost down and I’m doing everything I can within reason.


The plan is to keep supplied with minimal periods of my distributors being out of stock. It’s a challenge for sure. Thankfully I’ve been able to have more and more produced at a time. The economy of scale should help drop the price at some point assuming no nasty surprises.

I don’t intend to stop improving the design. The improvements I have in mind are increasing the amount of power through the auxiliary supplies (like the 5V rail) and also maybe implementing the AUX output for applications like fans. Of course would love to hear feedback from users to help me improve my craft.


Fans are awesome! 12v fan or 5v?

Saw that prices started dropping on the ones LCSC provide recently :slight_smile:
Also see some indications on shortages getting better across the board.