Motor cogs during speed

ESK8 Electronics
1

Hello, i sorta finished my first build, but i have a huge problem.

Throttling from standstill works fine, but of course the motor will cog a little bit when i do that, because of the weight on the motor.

But if the board is rolling downhill and i don’t touch the throttle, meaning 0%, as soon as i accelerate the motor will cog and throw me off. The board will instantly stop and make screeching sounds. The same thing happens if i brake, but not always. The brakes usually work just fine, but sometimes the brake won’t respond until i brake a lot, then the board stops and cog. When i’m going downhill the brakes sometimes stop working aswell, basically the brakes completely die. If i jump off the board and throttle a bit forward, the brakes will work again. The cogging only happens when i’m not touching the throttle, meaning if it’s at 0% throttle and i move the thumbstick in either direction. Sometimes i can throttle from standstill and if i keep the board at speed then brake, the brakes will work just fine, but If i then start to accelerate again, the board will stop and cog.

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2

Share some info about your gear… Battery, Motor etc

1 Like
3

It sounds like you haven’t done, or didn’t apply a motor detection.

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4

Yes, i’m using a torqueboards 6374 motor. 36/13 gearing i THINK. I use a 50 volt 18650 battery, 9450 mah. Built it myself. I use the enertion vesc-x. I’m also using the winning remote. Orangatang kegel wheels.

5

Hmm i have done the detection and hit apply, is there more to it?

6

Were the VESC-x’s capable of 12s?

7

Did you write config after that then reboot VESC?

8

Yes it’s capable of 12s and i did write and reboot.

9

What is your motor KV? It needs to be 170kv max in order to stay within the erpm 60000 limit

1 Like
10

It’s 190 KV. What erpm are you talking about? I could also say that when i try to spin the motor with BLDC, it just makes a clicking sound, it won’t spin.

11

Try this

Motor max 80 Motor min -40 Batt max 40 Batt min -15

But it does sound like your hitting your set erpm limit

1 Like
12

You set the erpm values to 60000. If you have 190kv and 12s it means - 12*4.2[v]*7[poles]*190[KV] =~ 67,000.

Try checking the “hit erpm with negative torque” check box and try again, it might help.

1 Like
13

Ok i put BR ERPM to 60000,00.

But this happens when i do calibration: https://www.dropbox.com/s/7fe5pjhn7m1chd9/IMG_3884.MOV.mov?dl=0

14

Hmm, Its seems like the motor loses it’s poles position for some reason.

1 Like
15

Slightly increase your low duty at detection to about 0,1… but shouldnt make a difference in the parameters received

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16

Wow thanks, it works! But what does the Min ERPM really do? It’s at 850 now.

17

My guess is you’ve got a loose connection. Perhaps you haven’t done motor detection. Do you have hall sensors or not?

1 Like
18

No it’s sensorless

19

that’s how you street your face

2 Likes
20

Hmm Then I probably got it wrong