FSESC 4.20 FOC compatible?

Most of my parts for my second build have arrived, so I will soon be out riding. I was thinking of setting up FOC rather than BLDC this time. I have the dual FSESC 4.20, what are your experiences when it comes to using FOC on this VESC? DRV chips blowing? Or is it working well?

Please share your experiences!

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I don’t know when you bought your vesc but the latest batches of 4.20 duals from flipsky are more reliable in foc I have used a older one in a build and if you stick with very conservative settings then you could run foc on it.

I bought it like a week ago, so I assume it is one a the latest batches. I have set up a mode on my Metr Pro with 30A batt max, that I will most likely cruise around on.

Do you know if the 6.6 is better for foc than the 4.20?

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I don’t have a new one, mine is from beta. In my experience, if you have the FSESC 4.20 Plus you are good. If you don’t have the plus version you will need to lower the battery amps to 25a’ish or it will cutout.

The 6.6 is definitively Better but for cruising on flat ground the newer 4.20 is fine

I see. Do you mean 25A split across the two vescs or 25A each? In the last case it will be fine, since my battery only can put out about 40A total.

25a each, I max at 30a each on the non-Plus version. If I go over 30a I get cutouts on acceleration. The Plus version is awesome though. I can pump 50a with FOC on each side and zero cut outs.

Damn, should have known that before buying one :confused: Oh well, since max amps is 40 anyways. It is not like the esc is bottlenecking my battery. The build is cruise/comfort oriented also, so a higher amount of power should not be needed.

Thanks for the help!

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No worries, happy to help.

@mmaner I believe you could run newer batches of the 4.20 on settings simular to the plus @Gamer43 could elaborate.

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This might be the case. Maybe the reason @mmaner can run higher settings on the plus is because the plus he has is a non-beta verision while the other one is a beta version? Only speculating here, but it does not sounds totally unimaginable to me.

they are both beta, but I have a plus beta and a non plus beta.

I see. Guess I will have to try out higher settings on the non plus to see if it works or not. At the moment I do not have a powerful enough battery for that. But if I decide to make a more powerful one I will report back in this thread with the results.


I had a new 4.20 ordered directly from Flipsky, verified the resister update and everything, foc on 10s worked about 3 rides and blew the drv.

Settings were motor 62,-62, battery 30,-10.
Got a drv fault in my living room, unplugged and all was fine, rode a few miles the next day, then went to ride to work and I gave it a kick start and hit the throttle and nothing, drv fault. It didn’t come back this time.

I would have warranty it, but my battery fell from my board and yanked the vesc onto the ground and damaged the mini USB port. Flipsky’s website says no mechanical damage so I don’t bother. The vesc still functioned fully and nothing else was damaged in the fall. It was a few rides/days later the drv crapped out. I ordered a 4.12 from eBay for 50$ instead of the 4.20 for 85$ running bldc now, but I miss foc for sure, torque was soo much better, and I have a lot of stop signs on my way to work that I slow down to a crawl and bldc seems to not accelerate as nicely

Sorry to hear that. Flipsky esc seems to be a real hit or miss kinda thing. Either you get one that works fine or one that breaks down really easily.

Makes me kinda think of quitting DIY seeing all these vesc never seems to last. Even foxboc unitys have their issues. Maybe dual vescs from trampa is the next step?

Anyways, talked to flipsky. The said that there is now way that the product itself is faulty, since the double check everything before shipping out the order. However they were willing to give me 50% discount for the replacement. So I guess I have to go with that.

Lol 50% huh? They offered me 5%

Oh that sucks. Do you have the new vesc running over can bus or is it a single drive build?

bldc seems a bit safer, so I will program it to run that instead of FOC this time. Then maybe further down the line when I feel a bit more ballsy and prepared to sacrifice my VESC, I will try out FOC again.

Single drive. I’ll run this one in bldc while I save up for a 6.x vesc model that I know won’t bite the dust at any moment.

Does anyone know how to use the single PPM cable on the FSESC 4.20 Dual (not the ‘plus’ version) to control both motors? Is a Can cable my only option? I was hoping there was a setting in Vesc Tool, or the hardware itself, that would let me do a split PPM sort of thing even though the esc only has a single PPM cable.