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How to drive Brushed motors with Brushless ESC's?
#1
Question 
Hi,
I am becoming a bit crazy trying to find the proposal made by Sean in the motor controller: Using a Brushless ESC to drive Brushed motors.
I am learning about SimonK and BLHeli for the ESC's, but not able to find it.... at least the matching of hte firmware with the ESC
I found little or no information... the best approximation that I got is this repo:
https://github.com/amcchord/MegaBrush
And this old post
Obviously my googleing skills are getting worse and worse.


A bit of light/guidance will be appreciated.

Tanks in advance.
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#2
(2020-10-23, 10:40 PM)fleming Wrote: Hi,
I am becoming a bit crazy trying to find the proposal made by Sean in the motor controller: Using a Brushless ESC to drive Brushed motors.
I am learning about SimonK and BLHeli for the ESC's, but not able to find it.... at least the matching of hte firmware with the ESC
I found little or no information... the best approximation that I got is this repo:
https://github.com/amcchord/MegaBrush
And this old post
Obviously my googleing skills are getting worse and worse.


A bit of light/guidance will be appreciated.

Tanks in advance.

I gave up on the ESC's although I have a box full of heli ESC's
The popular Hobbywing 30A ESC's seem to no longer use ATmega-8 processors.
The different bootloaders in BLHeliSuite confuse the hell out of me

The BLHeli source is on Github:
https://github.com/bitdump/BLHeli

Hope it works for you.
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#3
Thanks for the feedback.
Yes, I just realised that the SimonK/BLHeli movement is quite old and not fully maintained with the hundreds of Chinese clones.
It was a dream to be able to re-use the drawer full of dirty cheap ESC's to drive brushed motors.
I have a couple o very old (more than 10 years) Mystery ESC's, ATmega with a PCB that is quite close to some supported by BLHeli... I will burn the firmware and see if they dont produce smoke... if they do, I close this page
I will move to a H-bridge and in parallel give a try to the VESC project (not for the PyPilot)
Thanks
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#4
I modified brushed_tgy significantly to make it work with pypilot but in the end I no longer use because it has higher power consumption (two atmegas instead of one) and the mosfets aren't as good either.

If you have a mystery esc, you will need to map which IO pins drive which mosfet gates and other pins such as temperature sensor and redefine them before recompiling and flashing the brushed_tgy firmware otherwise you may very well end up with smoke. I tested with blue series and afro esc as well as another type, but there are many more and they all use different pin outs.


I am using VESC for my boat's electric motor and ebike but not yet for autopilot.
https://www.youtube.com/watch?v=XgMlcdPjUc4

This would be a great esc, but it uses much more idle power (doesn't matter much though) as well as still needs adapters for isolation and a little bit of code written to support pypilot. Then it would work for brushed as well as brushless motors (which should have an angular encoder on the motor shaft) I would eventually think using a large outrunner motor on a ball screw with this arrangement would make an incredible actuator for an autopilot with high speed and efficiency while also working at low speeds and giving force feedback.

For a brushed motor, the VESC is almost a good fit, but after adding the needed components for protection (I already fried a VESC) as well as supporting everything needed, they become less cost effective than the motor controllers I'm already making for brushed motors, but not by a lot. For brushless they seem a good fit, but I've only used in sensorless mode, and sensored mode is needed. Now FOC control is reportedly buggy (vesc can smoke) with version 4, and vesc 6 and later are also very expensive, but maybe FOC mode isn't required for an autopilot control, it would just make it more powerful and efficient.
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#5
(2020-10-26, 09:08 PM)seandepagnier Wrote: I modified brushed_tgy significantly to make it work with pypilot but in the end I no longer use because it has higher power consumption (two atmegas instead of one)  and the mosfets aren't as good either.

If you have a mystery esc, you will need to map which IO pins drive which mosfet gates and other pins such as temperature sensor and redefine them before recompiling and flashing the brushed_tgy firmware otherwise you may very well end up with smoke.    I tested with blue series and afro esc as well as another type, but there are many more and they all use different pin outs.


I am using VESC for my boat's electric motor and ebike but not yet for autopilot.
https://www.youtube.com/watch?v=XgMlcdPjUc4

This would be a great esc, but it uses much more idle power (doesn't matter much though) as well as still needs adapters for isolation and a little bit of code written to support pypilot.   Then it would work for brushed as well as brushless motors (which should have an angular encoder on the motor shaft)    I would eventually think using a large outrunner motor on a ball screw with this arrangement would make an incredible actuator for an autopilot with high speed and efficiency while also working at low speeds and giving force feedback.

For a brushed motor, the VESC is almost a good fit, but after adding the needed components for protection (I already fried a VESC)   as well as supporting everything needed, they become less cost effective than the motor controllers I'm already making for brushed motors, but not by a lot.  For brushless they seem a good fit, but I've only used in sensorless mode, and sensored mode is needed.   Now FOC control is reportedly buggy (vesc can smoke) with version 4, and vesc 6 and later are also very expensive, but maybe FOC mode isn't required for an autopilot control, it would just make it more powerful and efficient.

I watched your video - very cool!!

The VESC seems to be geared for very high current applications - like skateboards, e-bikes and your boat motor but are there suitable "low power" (and lower cost) versions for driving an actuator? I'm assuming that 1.5 to 3A is all we should need.
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#6
The VESC hardware can handle perhaps 2-3x the current as my regular motor controllers for the heat dissipation. So a smaller custom version of VESC may be nice, but I also want my controllers to remain at 98-99% efficiency and not get very warm at all which is not really true of VESC if you put enough amps through it. VESC in brushed mode may very well be an option for hydraulic pumps for example, it's about the right size for that.

I don't really know of lower cost brush less controllers that are suitable. Whatever is used must be sensored because it is constantly starting and stopping. Most of the cheapest controllers are sensorless, do not measure currents. VESC seems like it can be adapted with user code because it has two analog inputs that could be used for rudder feedback and motor temperature. It has i2c that could be used for an angular shaft encoder (better than hall sensors) and the software supports this. So maybe a vesc with smaller capacitors and mosfets would work for tiller pilots, but it would end up costing more than the standard 4.12 clones for me to make it.
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