FOC making weird clicking noises on startup

I’ve got a dual motor setup, pair of 100kv hubs and vesc4.12’s, BLDC works fine on both of them, i had to upgrade c18 to get FOC working without drv errors on one of the two sides, but that side now makes clicking noises and shakes pretty damn badly accelerating from low speed, like regular bldc jitter but much worse, doesnt happen unloaded at the same erpm, any ideas?

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I have the exact problem on FOC with one of my VESCs now. Nfi idea why, woukd love it if someone could solve this issue.

I know you’ve upgraded but 4.12 does not like foc unless its a focbox so maybe tag one of the enertion boys to see if they can help.

Ok, i might just go back to bldc, shame as it’s so quiet on FOC, but i can’t afford to break anything

Yeah it seems to be the case. Problems on foc with 4.12. I’m not in any way able to help with the tech on that but I know its never worked well for me on anything other than a focbox. I like the loud whine of my sk3’s though and would not trade that esk8 signature scream for anything. BLDC all the way.

maybe in the future i’ll upgrade to a unity or something, but i guess bldc will work for now. FOC was weird, working better for climbing hills, but seems like it has a lot less speed for a set current

sensored or unsensored?

hall sensors correctly setup on both

I’ll just leave you in @Deodand capable hands.

are you running 2.xx FW or 3.xx?

Latest one, 3.40 i think. it’s a bit weird that one of the motors needs a tad more current to spin up, but that might be because i have invert motor direction set on that because i CBA to fiddle with the wiring

Interesting, I’ve seen this problem on the 2.xx FW. There’s a couple possibilities. Have you tried increasing the sensorless ERPM setting under MOTOR SETTINGS>FOC>HALL SENSORS in the vesc tool? Try 5k erpm instead of 2.5 k default

Also can you tell me your motor inductance/resistance values?

Ok, possible it is that as it is a 36p motor, i’ll try that for sure. I still think it’s unusual only one motor is having issues, but oh well

I’ve had some issue where the current controller time constant is mismatched with the motor and it has caused jitters on me. Problems with only 1 of the motors then? Strange. Screenshot of the hall sensor values would be helpful also, possible one of your halls is being weird.

Edit: suppose if the halls work in BLDC they should be ok… hm.

resistance was 88mohm, then i reran it after a run and it was 100mohm, Inductance is 24.65 uH, lambda is 7.005.

The differences are the motor that works perfectly is direct soldered to the vesc with cut down wires, the one that’s behaving weird is using a vesc that i got about a month after the first one, but both from maytech, and the wires are untouched

Try sensorless Erpm change first, if that doesn’t work then try the following:

25 uHenry / 100 mOhm = 250 uSeconds. Try changing T in the FOC detection to a lower value closer to 250 u Seconds instead of 1000 u Seconds.

Ok great thanks, i’ve got to go now as it’s past midnight where i am, but i have hours tomorrow to check and test and fiddle, Thanks so much for all your help, I really appreciate it

No worries, dump some screen grabs here if problem persists.