Motor issues Sensored FOC

My build has been having some strange issues lately and I figured I would reach out to the hive mind for help.

I have a single 6374 motor with hall sensors connected to a FS6.6 VESC. It it’s setup to run sensored FOC.

Very recently it has developed some issues at low speed. The motor starts turning like normal, then it seems to catch, then it continues like normal. Once it gets past the transition to sensorless, it works perfectly.

This obviously lead me to believe that one of the hall sensors is messed up. So I took out my multimeter and measured the DC voltage difference between positive and the signal pins from the sensor. All three signal pins alternated from +5v to +0.5v as I rotated the motor.

Then I went into VESC tool and ran a hall sensor detection. It successfully ran, and I applied those settings. Still no dice.

I ran the tool a couple more times and recorded the results to see if they varied.

Here are the results

Run number | Sensor 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7
1 | 255 | 149 | 18 | 181 | 84 | 118 | 50 | 255
2 | 255 | 148 | 15 | 180 | 87 | 116 | 45 | 255
3 | 255 | 146 | 17 | 179 | 87 | 116 | 48 | 255
4 | 255 | 147 | 17 | 179 | 86 | 118 | 49 | 255

All of the results seem very similar to me, but I don’t have a functioning board to compare them too.

My VESC configuration and firmware has not been changed except for the hall sensor configuration and using profiles in the official VESC app.

And now for the kicker: While making this post I turned the board off and let it sit for about 2-3 minutes. I turned the board back on for shits and giggles, and it works perfectly.

Now I think that the issue was either caused by changing profiles, setting a profile as “use until reboot”, or overheating in the VESC as the issue only seems to crop up after having been ridden for a while.

This might be the wrong category, and if so I’m sorry mods.

Fixed the category for you bud.
To me sounds like an over heating issue. But I have been lucky with my vesc/escs knock on wood. So I’m not the best expert for troubleshooting.

Out of curiosity, have you checked your phase wires? Make sure they are fully connected and no exposed connector. From motors all the way to the esc

1 Like

That was my first thought. They is a tiny sliver showing where the bullet connectors are, but the heat shrink covers it well enough that there is no shorting.

1 Like

did you only do a hall sensor detection or did you do a full foc detection? i find sometimes my foc settings drift

Just a hall sensor detection. I didn’t want to have to redo my entire configuration.

5th day update:

Issue has not returned, so I’m leaning towards overheating, or a bug with profiles.

do it anyway

1 Like