ESC turns off when motor stalls

Hello. I am currently using a basic ESC and pairing that with a sensored Tekin motor (Tekin’s Element Proof ROC412 HD). I know that this is not the ideal pairing, but size and power restraints leave us with these two options.

I am currently trying to solve a propulsion issue where the motor will occasionally stall. We have conducted a suite of tests and are hoping to have some of our questions answered.

When we have our motor clamped and send a signal for the motor to spin, the motor has 4 stuttering “ticks”, then the motor shuts off until it is brought back to its neutral position. I was wondering if this feature is considered demag compensation or stall protection? Do these two features work together or are they completely separate? Something odd that we noticed is that this feature doesn’t occur when the signal we send is small (around 1512 - 1520). How would the speed of the motor impact this feature?

Additionally, we were wondering how the ESC knows when to stop. Is there a list of reasons or criteria in which the ESC will automatically turn off (ie: voltage protection, heat protection, etc.)

Thank you!

Hi @corinna -
We received your support email, but as you’ve asked here as well I’ll share the response publicly.
Hi Gavin -

There is a chance your motor has been damaged, if it does not operate normally when not clamped in place. When clamped, you are expecting vastly more torque than it can provide!

The motor has a KV value that is significantly higher than the Blue Robotics M200. This means it has significantly less torque, but can spin at significantly higher speeds - KV is a measure of rpm per volt applied.

The motor must be able to freely spin in order for the Basic ESC, or any sensorless brushless motor controller, to operate it. This is because the controller is energizing the motor with two wires, while “listening” to the third wire to detect the rotation rate of the motor, and send the correct timing of pulses of power to spin the motor. When you prevent the motor from turning, the controller is running a start-up sequence (which is always done “blind”) and not seeing a result - when this fails the ESC does need to be re-initialized with a 0 throttle signal before trying again. If you unclamp your motor you should see normal operation - but keep in mind that this motor inherently will not be able to spin at low speeds, and will have very low torque at the lower end of operation. This typically means such motors need to be geared for high torque applications, like we demonstrated in this guide. If you need higher torque, if not the M200 you may need a fundamentally different style of motor, such as a NEMA stepper. Do you have a torque specification you’re trying to meet?

As an aside, I wouldn’t expect that Tekin motor to last more than a few sessions in saltwater, as it is not intended for full submersion in such a corrosive liquid…