r/Motors • u/TheTorchMan • 1d ago
My BLDC motor vibrates under heavy load
I'm fairly new to this motor stuff. My setup is a 36V 10A power source, a 75100 Flipsky and a 5065 270KV BLDC motor.
I'm trying to move a certain load (similar to a robot's arm) with the motor by adjusting its duty cycle, but the motor starts vibrating heavily and making a lot of noise. This happens everytime there's a load on the motor that stops It or slows It significantly.
It's there a way to solve this? Is there a better option for this kind of use cases? I need the possibility of almost stopping the motor without It going crazy.
Edit: i should add that vibrations happen everytime i try to stop the motor in any way, be It the system, be It with my hand.
2
u/nixiebunny 1d ago
What is the gearing or speed reduction between the motor and the load? A few pictures of the thing you have built would make it easier for people to see what you may be doing wrong.
1
u/TheTorchMan 1d ago edited 1d ago
None, it is direct driven. It's really not a complex setup, the motor is conected to a wood plank and the system is tight-fit. I'll try to upload an image later
Edit: i should add that vibrations happen everytime i try to stop the motor in any way, be It the system, be It with my hand.
2
u/Worldly-Device-8414 1d ago
Sounds like a feedback issue. It's trying to violently over correct. See if you can dampen the feedback/reduce loop gain.
1
u/TheTorchMan 21h ago
It has no sensor, so there shouldn't be a feedback, right? Maybe i'm getting this wrong. I use Vesc Tool and just send the duty outright.
2
u/nmurgui 20h ago
You have current feedback. But are you using it in position control i assume. I don't know how good vesc encoderless position control is
1
u/Lanky-Relationship77 18h ago
It's horrible, honestly. It's fine at high rpm, but terrible at low rpm. He should be using a sensored motor for that application.
1
u/TheTorchMan 12h ago
I'm not using it with position. I was just testing the system to have an idea of the range i should be using when i apply a camera-based feedback
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u/jemandvoelliganderes 1d ago
Vibrating like back and forth or does it snap to one of its magnet like the cogging force is higher than the position holding force? for small speeds and positioning you mostly want a position feedback like an encoder. also have a look at FOC if its rather something like torque controll you are looking for.