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Blctrl real speed controller?

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Hi all, I was wondering if the blctrl (I had my hands on a 1.2 version) is a real sensorless speed controller. I hooked it up to a variable pitch propeller and I found out that the rotor speed varies A LOT varying the pitch angle (and the torque load thus). What really surprised me was not the instant variation but the absolute lack of compensation. A good electronic drive speed controller should at least try to compensate for the load variation and, at least slowly, reach back the reference speed. Is there some setting to toggle? Is this possible with blctrl?

Thank you all.
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Hi all, I was wondering if the blctrl (I had my hands on a 1.2 version) is a real sensorless speed controller. I hooked it up to a variable pitch propeller and I found out that the rotor speed varies A LOT varying the pitch angle (and the torque load thus).

Are you testing a BL-Motor-Ctrl V1.2? That one is certainly limited in power.

Could you test with a modern BL-Motor-Ctrl V3?
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I can't right now but I really doubt it is a matter of power given the fact that I am testing it at around 8 A which is way less than the actual limit of the device... Everything is powered with a large switching regulator harvested from an old PC. I find it difficult to understand how such a controller could work "for every" motor without tuning the parameters...
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I find it difficult to understand how such a controller could work "for every" motor without tuning the parameters...

The BL-Motor-Ctrl V1.x has no setup, you need a BL-Motor-Ctrl V3 for that.

BL-Motor-Ctrl V1.x (and V2.x) is not intended for every motor, it has to be a 14 pole motor e.g. Robbe ROXXY 2827-35. Also this motor controller is intended for fixed pitch propellers and does not have active speed break.

Which motor do you use?
« Bearbeitet von Foersom am 25.02.2016 22:45. »
Mitglied
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I use the AXI 2208/34, which is in fact a 14 poles motor. Do you think the blctrl v3.0 would solve the problem?
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I use the AXI 2208/34, which is in fact a 14 poles motor. Do you think the blctrl v3.0 would solve the problem?

I am not really sure what you are trying to do. If you could describe more in detail what you aiming to do, perhaps there is more people that can help you.

What size is the propeller you are using? What brand / model?

Do you vary the propeller pitch while motor running?

Are you aiming to build a multi-rotor or something completely different?

Do you control the BL-Motor-Ctrl V1.2 with a flight-controller or with you own developed program / electronics (through I2C)?
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Do you think the blctrl v3.0 would solve the problem?

Perhaps this video about speed control on BL-Motor-Ctrl V3 might interest you.
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Yes, I will vary the pitch while the motor is running.

I'm building a variable pitch quadrotor. I'm using four AXI 2208/34 motors with the AXI EVPU variable pitch propellers. The propellers are 10 cm long.

I'm developing the control electronics myself. I supposed I could buy a speed controller off the shelf without the need of developing a custom one since my requirements shouldn't be that strange. I need a sensorless SPEED CONTROLLER for brushless motors, which means a controller capable of compensating the rotor speed when the load varies, this is not a strange thing among industrial applications.
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The video you posted answers my question. Thank you. It is kind of misleading to call the 1.2 version a SPEED controller, it actually doesn't control the speed, it is just an open loop drive with no compensation whatsoever (you can't actually set a reference speed, it's much more like a torque control in some way)... I'm sorry I wasted some money...
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I'm building a variable pitch quadrotor. I'm using four AXI 2208/34 motors with the AXI EVPU variable pitch propellers. The propellers are 10 cm long.

I'm developing the control electronics myself. I supposed I could buy a speed controller off the shelf without the need of developing a custom one since my requirements shouldn't be that strange. I need a sensorless SPEED CONTROLLER for brushless motors, which means a controller capable of compensating the rotor speed when the load varies, this is not a strange thing among industrial applications.

That sounds exciting but certainly it is a speciality. It is not what those BL-Motor-Ctrl V1.2 were designed for. If you look in the MK shop that is no variable pitch multi-rotors.

Whether you can use the BL-Motor-Ctrl V3 for this purpose, I suggest you ask HolgerB and refer to this thread.
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It is kind of misleading to call the 1.2 version a SPEED controller

It is called a brushless motor controller. Where do you see it sold as speed controller?

Anacleto86 meinte
I'm sorry I wasted some money...

This is user forum. I have no comments about this.
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Oh sorry, I didn't mean to be rude and I'm not addressing this particular device. It is my understanding that these kind of controllers (all of them, of all brands) are called ESC, as Electronic Speed Controller while they are really not on a technical point of view... That's all... I actually didn't even know, or cared, that you were part of the staff. Thanks for your help.
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Oh sorry, I didn't mean to be rude and I'm not addressing this particular device. It is my understanding that these kind of controllers (all of them, of all brands) are called ESC, as Electronic Speed Controller while they are really not on a technical point of view... That's all... I actually didn't even know, or cared, that you were part of the staff. Thanks for your help.

Yes I know that many companies call it an Electronic Speed Controller, but I am not sure that all of them includes speed braking. Same way as it is called a speeder in a car, but that does not guarantee that it can be used to stop the car.

I fly an octo-copter based on MikroKopter. The system works very well. I help people here, because I remember how difficult it was when I started to understand all the technical details.

One of the great things about MikroKopter, is that the two main engineers HolgerB and IngoB participate in the forum and sometimes answer technical questions.
« Bearbeitet von Foersom am 26.02.2016 14:14. »

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