R/C Tech Forums - Brushless sensored weird behaviour

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Brushless sensored weird behaviour

Hi,

last year I raced a club championship with 10.5T motors, I ran a TrackStar motor and a HobbyWing ESC. All performed well. This year I switched clubs and I needed a 17.5T motor, so I bought a motor of a fellow club member, a SpeedPassion V3.0 motor. Today I fitted it and tried to race it, but it wouldn't budge. There is a humming / beeping noise when I press the throttle, but no movement. When I disconnect the sensor cable, it runs as smooth as an unsensored motor is supposed to.

But here is the stange thing; when I connect my TrackStar again, that runs well. So the ESC and the sensor wires are OK. But when I put the SpeedPassion on a test bench (to determine timing), that motor is given a clean bill of health as well! We tried with different sensor cables, but to no avail. I tried to run the SpeedPassion in reverse, maybe the sensors didn't agree with the direction of rotation, but that doesn't change anything.

A free banana for the person that solves this riddle...

Cheers,

Hugo

ABC wires are wrong.

Ah, right. What do you mean? You mean I connected the motor wires in reverse? I did swap two of the three so see if it would run in reverse. It didn't. Please explain.

Thanks,

Hugo

Might have bad sensor wire. Last year my Reedy 25.5 would just randomly cut out. Sometimes I could race a full day without problems, got to point where couldn’t finish a race. First few time I would turn it off then on and it would work. But got progressively worse.
Replaced sensor wire and never had it again. When I looked at the old wire I found 2 tiny spots were the coating was gone, bare wire.

Good idea, sorry I forgot to mention we exchanged the sensor wires. It didn't solve the problem and the problem was constant / repeatable.

Thanks,

Hugo

With sensor cable plugged in you can't just reverse any two wires like you would/could in unsensored anyway, it has to be A-A, B-B, C-C.

That aside I don't really know what could be causing it since the senor cable and the sensor board itself seem to be working otherwise. Sometimes there are rare cases where a motor and ESC can be incompatible in sensored mode, maybe you stumbled into such an occurence.

I would put the motor on an analyzer if someone at your club has one to help you test it... could be a bad sensor board on the motor.

Put your speed control on hybrid mode, not full sensor mode................