Might go on my first ride after all this lockdown thing and I’m not very keen on street face on the first ride directly, so I wanted to bring up this issue.
Do we have a fix for it or was the topic closed with „you need to set the duty cycle current limit manually on each vesc“?
I set it up in each VESC separately
So that’s it?
No fix to it?
And does it really solve the problem?
What if people do not know about it and just use the wizard 
isn’t that a bit dangerous?
The Wizard will get an update soon.
Do as I wrote and change the DUTY CYCLE CURRENT LIMIT START to 85% for each vesc.
It works great after that.
For the first time I can punch the throttle and keep it pinned down until I reach top speed even in steep inclines.
It also makes getting off the throttle at top speed smoother.
Honestly I had that problem since day one.
I am surprised nobody else had noticed.
I was just cautious and usually slightly let go of the throttle as I reached top speed.
Most of the times it wasn’t a problem but the few times I reached top speed under heavy load, things got sketchy.
I don’t know if some sort of smoothing was taking place in other vesc tool versions.
THIS so much!
letting off the throttle from a good top speed run always gave me the heeie-jibbies… like everyone else here we thought that was a VESC feature… hahahaha and just lived with it… then last week I was lookin’ at the trampa tutorials to see if I could gleen some info… and the vid i posted above came up…
I tried it at 85… and I like it…
I still have to look into that HFI_erpm threshold setting that @b264 is on about and see if that is another uncovered gem!!
It’s called Sensorless ERPM HFI in the Motor Settings > FOC > HFI screen
Lower that to 750
You can thank me later
Synopsis time:
It just turns off HFI really quick once the rotor gets turning. In fact you can lower it even more than that, try 500. It only needs HFI when it’s not moving at all.
Once it turns off, you can dump as much power as you want into the windings. So basically it increases the window during which there is no cogging risk for extra high motor current levels.
interests me… thanks I’ll giver a go this weekend an report back if I’m a fan of your unfound gem!!!
thanks meng!!!
Just wanted to let you guys know, the stuff regarding max duty cycle is on Vedder and My radar.
Vedder has pretty good theory on what is going on, he made the maximum duty cycle limit work better which is somewhat ironic. Basically before as you approached max duty it wouldn’t correctly prioritize Q-axis current (the current that makes torque) over D-axis current (no torque). Now it does this more efficiently which is good, the problem is it causes a more abrubdt feeling torque loss when the limit is come up against and can cause oscillations with some setups since it is a rapid change. The solution is to soften the change as per the setting @Trampa is pointing to.
I’ve talked with Ben about the best ways to add this into the wizard for next release. It does cause a slight decrease in top speed power in the last 5% so people on e-bike or expert users and other applications might not want this limit imposed without being informed.
I have that limit set to 85% on all 4 escs, but still getting oscillations on profile limit 40km/h. When I set 30km/h it’s ok. My setups max should be about 50km/h.
What if it’s also caused by every motor having slightly different erpm? Like when wheels have different pressure, so on the same speed you get little different rpms. But traction control erpm difference is at 3000 erpm…
I just lowered mine from 2000 down to 1000 and it was all sorts of fucked up. What works for you might not necessarily be best for everybody else.
Has anybody else experienced weak torque on startup with HFI? My board only delivers torque once it is well and truly rolling, no off the line punch. Funnily enough tho, in ‘current’ mode, reverse has heaps of punch
I tried inverting motor directions with the same result. Forward sucked, reverse was great.
Wtf?
Well the solution is right in your face. Change stance and use Reverse as forwards, forward as reverse. duh.
That’s a work around, not a solution.
I’ll see if I can get similar behavior this weekend.