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ESC stops on rapid reversal


(Andy) #1

Hi,

maybe it’s a common issue, but I didn’t notice it when using another ESC for cars. I am testing the Afro ESC with updated firmware for rotation in both directions. For example, when I quickly change the pulse length from 1400 us to 2000 us, the red light on the ESC blinks, the motor stops and it doesn’t respond until I move the throttle to the stop position (1500 us). When I move the throttle to the stop position for a second, the green light blinks and the ESC continues to work normally.

It works fine only if I continuously move the throttle from 1400 us to 1500 us and then to 2000 us (i.e. I wait until the motor stops before reversal).

It also works fine if I quickly move the throttle from 1500 us to 2000 us (i.e. rapid acceleration from zero to max. works).

I tried it 100 times with a few Afro ESCs and it’s always the same. Maybe it’s designed so intentionally as a protection against current spikes or to save the motor. Is there any way to allow rapid reversal (like compiling the firmware with another variables)? I can’t find any info about it. I only want to ensure that the motor won’t stop responding in any conditions because it is critical for my application. When I was using another ESC for cars (“Turnigy TrackStar 25A 1/18th Scale Brushless Car ESC”), I was able to quickly change direction even from 1000 us to 2000 us without any issues.

 


(Rusty) #2

Andy,

I’ve noticed the same thing with rapid reversals. However, in my experience, it only happens in air. It seems to be related to the momentum of the spinning rotor causing issues. In water, the rotor is slowed down almost instantaneously so there usually isn’t any delay in reversing.

In general, I wouldn’t recommend rapid reversals like that because it definitely puts a lot of strain on the ESC.

-Rusty


(Andy) #3

Thanks for the info. So it looks like some kind of protection. I know that rapid reversals are painful for the ESC and the motor, I just need to create a design as failproof as possible to limit human intervention.

 


(Rusty) #4

Andy,

Yes, I think so. Have you tried in water? Do you get the same result?

-Rusty


(Andy) #5

I didn’t try it in the water, but I will try it with M100 within 1-2 months.


(Rusty) #6

Andy - okay. I think you will have much better results in water.