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Small motor with vesc?

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spacemango
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Small motor with vesc?

 

Hello! I am completely new with this and have a few questions. 

Can I use the VESC to control a very small motor that should be run at 6V? I noticed that the VESC needs at least 8V but is there a way to come around this? Could I just lower the max duty cycle? 

 

TheFallen
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VESCs aren't great at small motors, why do you want to use a VESC on this motor?

The VESC needs around 8-12V to actually turn the MOSFETs on as well as regulate for the logic so you do have to run it at more than 8V. But brushless motors don't really have a maximum voltage so you could run the motor at a higher voltage and then use the VESC to limit the power/speed of the motor.

spacemango
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Well its for my thesis where I have done simulations on nanosatellite class reaction wheels driven with FOC and since there is not enough time to implement this from scratch on the real system my supervisors told me to use VESC to see if FOC will improve the performance of the reaction wheel or not, but I'm starting to think this is a bad idea haha... I have tried using 10V and limiting the duty cycle but  it just doesn't want to spin. Should I go higher with the voltage? What would you say is the lowest voltage that is needed? 

TheFallen
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I've not run a VESC at less than 24V so I don't really have much experience of your situation.

pf26
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Just out of curiousity, I tried a VESC 4.12 (Flipsky FESC4.12) and it works fine above 9Volts.  (the DRV8302 chip is said to work >8Volts, and the VESC has some config setting to stop below 8Volt by default). The Fets may need a bit more to achieve full performance, but who cares.

Anyway, you could also power the motor from a higher input voltage and limit duty cycle/speed as you mention. There is only a slight performance penalty as the motor inductance is used as a dc/dc converter. Obviously, if your motor has extremely small inductance (below 5 microhenries), there might be other issues.

spacemango
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I'm running it at 9V now with limited duty cycle and it works fine! The problem for me was the hall sensor table, the measurements in the VESC tool just doesn't want to work. But with an oscilloscope I came around that problem.