Agreed. I saw a couple of other people mentioning it but no pinpoint on why it’s happening to some and not others.
2 Likes
Ha… you got wobbling, i got motors cutting out at completely different speeds. Next thing i know my back wheels start turning when i accelerate further. 85% seems a good balance in the 60’s down shitty roads
@itsrow any topics i can read on the 35khz problem? It it a erpm issue?
it’s not dead. it will live forever! but low activity is good.
It’s been int he back of my head to get my head round the problem that @rusins wrote up that I presume you’re also experiencing and whatever the whole set duty cycle limit start lower advice is about. ie to know what it was and when in the versions history it was introduced and what conditions triggers it.
as it stands each time I’ve read it I’ve gotten confused and didn’t have enough time to focus on understanding it better.
It would help if that topic had it’s own thread where that stuff got worked out.
And then I’d update the first post with a succinct summary.
4 Likes
No not an ERPM issue, providing you weren’t having ERPM related issues beforehand. When you increase the sampling rate the STM32 has to physically refresh more time per second and if you run out of processing power when youre riding the esk8 it will fault and cut motors completely which is arguably worse than oscillating/inconsistent power delivery.
2 Likes
Good to know!
I’m running 30khz because at default 25 on fw 5.1 i can hear hissing coming from the board and the hall sensor start is anything but smooth. I just don’t want to eat shit at over 50km/hr.
To the best of my understanding, i can get a cutoff at too high switching frequency from standstill, provided it’s too high, is that right?
1 Like
Absolutely correct.
1 Like
Im creating a new topic specifically for the oscillating motor problem, if you want I can tag LHB or something to clean this up, didnt mean to steal your wiki out from under you.
nice. 
a little chatter is fine. no worries. more concerned with getting it better understood.
1 Like
Fess… I wonder if this has anything to do with that weird ass webble-wobble that my board was experiencing when we sk8ed last?
But it was all Unity and Unity FW… Never changed… Never fucked with the settings… I postulated the experience had something to do with traction control… I know it wasn’t from thermal throttling or max duty cycles…
I honestly haven’t fukked with that board since…
1 Like
cross linking that you did.
1 Like
I’m guessing no. because those wobbles weren’t occuring at max duty cycle which I think the other issue is about.
maybe traction control? maybe just something too loose?
1 Like
out of boredom I just checked… traction control was turned off… I know by default it was turned off, but I know 100% i activated it…
so I’ma gunna charge up the board and giver a test with traction control activated!
EDIT:
what’s everyone using currently for Max eRPM difference in setting up traction control?
3 Likes
You should calculate it from your gearing, voltage and motor kV. Usually using a calculator to find your top speed, top ERPM and dividing it to get a 3-5KM/h difference is usually enough.
2 Likes
Stock 3000ERPM, about 3kmh with my gearing.
1 Like
a qwik 10 mile run…
traction control on… the saved eRPM, or default was 3k eRPM… i used that…
it drove pretty OK… no low speed wobbles except over some wonky terrain, lowered the eRPM to 2500 which pretty much equates to 3 km/hr on my setup…
much much betterer, it was kinda hot so I’m going to charge the board back up and go back out testing this evening…
science
this chatter also deserves it’s own thread. “Traction control tuning != known bad firmware versions” 
3 Likes
flag my belligerent, non-rule following self, @fessyfoo, if you feel it detracts from the thread…
I promise I’ll not be bitter!!!
1 Like
So with all that being said, what FW can be considered to be safe to use?
Without digging for 2016 reported bugs, 5.1 with duty cycle current limit start at 85% if your board can top out the speed limit
3 Likes
Sorry but I don’t understand what you mean by that 
I have a VESC 4.2 and 6.6. What FW would be the best to use?
1 Like