VESC Help Please! Motor Judder

Here you go…

I’m gonna compare your settings to mine when I get home from work.

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Did you do your motor detection with nothing on the motor? I mean not even a pulley on the shaft? and did you apply the results and write configuration?

And did you do the controller setup pulse width setup on the app config page / ppm tab?

Here is a good tutorial for the pulse width setup:

What is your gearing ratio? Your batteries are in series for sure? For 6s your battery max cutoff start 22,5 V is maybe too high. Set 21V for max and 20V for battery cut off end.

No, i did the motor detection etc. with everything connected, pulley, chain, sprocket etc. Are you supposed to do it with nothing on it then?

I did the controller setup, my ‘rest’ is close to 50% but it all seems to be correct. I already used this video for that :slight_smile:

This is my gearing ratio. 10T / 30T

Like i said, it was working great with my old boat ESC, except no brakes! :frowning:

You need to redo your motor detection with everything off the motor.

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OK, I’ll do that…

Hey guys, I’m back again!

I’ve re-done my motor detection and changed around the limits. I’ve taken it up to like 115A for the motor and changed couple of other settings… that seems to have made a bit of a difference. The acceleration is better, and top end is better, however, I’m finding that when I’m full throttle (and it’s accelerating slowly but … nicely), sometimes it will cut out and I just coast… no brakes, no more accelerator, until a few seconds, maybe 10 have passed, then I get control back again… what could that be? Is it getting too hot and it’s too much for the mosfets?

After that test I decided to mess around a bit more and I’ve enabled FOC!!! I just have to say, FOC is amazing! Things got a bit more smooth, MUCH more quiet, a bit more punch in the acceleration and slightly better brakes, however, I’m still getting this cutting out issue? Any ideas?

I’m guessing that something is hitting a protection parameter. Maybe voltage sag causing low voltage trigger Or temp trigger. Your pulling high amps at 6s

Hmm ok. Do you suggest any solution?

I’m out on it right now and on some, even just slight inclines it just can’t cope! Never had that problem with my old ESC, could drag my fat arse up ALL the inclines in my local park…

If you´re already going with a vesc, throw in another 3s battery to go to 9s. No problem with your system and will give you a nice boost :slight_smile:

Yeah, I don’t mind doing that, although I’ll have to get a new enclosure etc. but I just don’t know why the VESC seems to under-performing a cheap 120A boat ESC? I’m a little disappointed if I’m honest.

The last ESC, the boat one, even got me up this really steep hill near where I live. Although it was only for a short burst, just to the car, it seemed to handle it no problem. With this VESC it wouldn’t even get me up the slight hill leading up to this steep hill :frowning:

I really think it must be a dud.

Calculation: 120A at 6s = 120A x 6 x 3,7V = 2664W max output of your ESC 50A at 6s = 50A x 6 x 3,7V = 1110W max output of your Vesc

Like I said before, Vesc at 6s is not a good idea in my opinion. You can use it if you´re only cruising slow on flats, but other than that it heats up too fast and I´d go with a ESC at 6s.

9s will be an other league

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Oh really? It really makes that much difference? I had no idea…

OK, I’ll try adding another 3s pack, I do have one somewhere, just need to make up a connector cable… (or buy one)

I’ve also just looked again at the spec of the motor and it’s max loading is 60A and I have the VESC set to 115A!!! :frowning: Ooops!

As Tarzan says, but even still it’s surprising as it sounds like you hit an over-temp limit so soon on 6s.

You can forget what’s presented as the max amp loading number of the motor and just watch it’s temp and that’s the real limit

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your combination is just unlucky. Small motor + 6s and Vesc is really heating up everything. Go with 9s or even 12s if you want. Next upgrade should be a 6374 to keep you going :wink:

Fair enough. But how come that cheaper ESC performed so well though? Honestly, although I had to be really careful with putting the power down, it was fast and really strong in terms of torque. With that ESC it felt like this smaller motor was more than enough for my needs…