afro ESC with separate BEC

[David]

I’ve seen some people say to use a bec with afro 30 speed controls and others that say it is not necessary. Under the suggested parts list it says use a separate bed for the afro 20 esc’s but it does not say that for the 30’s. I have afro 30 amp esc’s I plan on using and I would like to know if I need to use a separate BEC for the tail servo.

Thanks, David

[Tiernan85]

This is something I had also asked in one of the blogs. Here’s the question and replies to put your mind at rest 🙂

Tiernan85

Sunday, December 14th, 2014 at 01:13:36 – Reply

Thanks for the video David. Question for you or anyone else with some info. I’m using the Afro 30A esc’s with the 900kv ntm motors and 4s. These esc’s have a .5A BEC. First: Do I need an external BEC? Or is it safe the way it is? Second: Do I need to disconnect the BEC’s in the other esc’s? Or is it again ok to have power going to channel 2 and 3 on the mini board? Thank you.

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Patrick

Sunday, December 14th, 2014 at 06:10:03 – Reply

It’s cool, the bec in the Afro is linear so they can be run in parallel. Since power rail is common on m2-8, you will then have 1A available to power the servo. .5A is plenty for the board and receiver. No external bec required. I don’t think I would power anything else with that, as all available power will be spoken for.

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RCExplorer – David

Sunday, December 14th, 2014 at 12:12:29 – Reply

Like patrick said, the becs are linear so they work together. 1A for the servo is enough 🙂

[Terje]

I have been running 2x30A Afros with BEC + 1x20A Afro slim without BEC on my first build running the Flip32+. That can be done because the Naze32/Flip32/Flip32+ has a common rail that combines all M1-M6 connected liniar BECs to provide in my case 1A to be used for the Rx, FC and servo.

Using the KK2.1.5 (mini) board, the M1 and M2-M8 are separated meaning only the BECs connected to M2-M8 will power the servo.

For my winter edition running the KK2 mini FC, I use 1x30A afro and 2x20A afro slims + 1x5v/3A BEC (which I need for the GoPro anyway)

[Alan]

Glad I found this post, I am new to RC and tricopters, got most of my parts together including 3 x Afro 30A ESC’s and a KK2.1.5 Board. I also got a 5v EBEC, I don’t intend any video at this point so will the Afro’s 0.5a (x3) be able to power the set up. I undsrstand I need to plug them all in with the BEC wires intact, would I need to put in my EBEC at this point. I am building David’s tricopter with scratch built frame and his yaw system. Turnigy 2836-11 750kv motors and 10 x 6 props. Still to get Tr, Rx and battery but looking forward to completing and flying.

[Tiernan85]

Yep you’re good to go. No BEC needed if you’re just powering the board and the yaw servo.

[Alan]

Thanks Tiernan85, this was the only part of my build I was not sure of having seen some of the comments about Afros not having the power. Done lots of reading up on tricopters and builds, as i don’t have the knowledge or confidence to ‘flash’ anything yet i went for the KK2 and Afros but did not realise they dont provide as much power as some other esc’s. One question, do I plug my tail servo lead into Motor 4 on the kk2.

[Tiernan85]

I was in the exact same boat as you about two months ago.

With the factory firmware, yes you will use channel 4 on the KK. As for flashing, it’s definitely worthwhile flashing the board. It’s very simple and gives you the full potential(which I’ve loads to learn still too) of the board. Again I was also a bit nervous, but it’s really easy. And you can always ask here for any verification if you’re not sure.

[David]

Another question relating to speed controllers. When your plugging in all your speed controllers to your flight controller, do you leave one “+” power wire to motor 1 and take the rest of the power wires out to the other motors, or do you leave all the power wires in place?

[Terje]

If your ESCs have linear BECs you can leave all in. Depending on how much amperage your BECs are supplying you might even have to.

It also depends on your flight controller. KK2 does not share power across M1 and M2-M8. Meaning power to M1 won’t power the servo on M7. Since the servo can pull up to 1000mAh and for instance the Afro 30A only has 500mAh BECs, you have to power the servo on M7 from the BECs on M2-M3.

You can NOT mix switching BECs. Since they are rare on ESCs that is almost a non-issue.

If you have a Naze32 or similar board, you can even power it with an external UBEC, and omit the power from the ESCs all together (when running 3 Afro 20A slims and such)

[Dronesruinthesky]

Thank you. This help me answer questions. We should have a sticky thread of informations going. Rather then thread stacking up based on latest replies

[Aaron]

I was using 20A AFRO esc’s just fine for a while. No alterations to them just as David explains.
When I connected a Gopro to M2-M8 rail and started flying more aggressively my Gopro would often turn off during flight. Then one day the Esc on M2 started getting very hot was supplying 2.5V and eventually popped and died.
Are we sure we don’t need a UBEC when using the AFRO 20 esc’s AND a Gopro?
After some research I found that the AFRO’s suggest this also in their info PDF.(below)

Thanks

Attachments:

1. AFRO-Esc-1.pdf

[Aaron]

ALSO, if we should use a UBEC when using a Gopro is it better/cleaner to connect it to KK board and then power the Gopro off the KK, or power just the Gopro with the UBEC?

[Siclair]

Acutally,

I got a respons from David regarding this very matter and combined with a naze32 the recommendation was not to use the ubecs from the afro’s. The margins might be too low. On the other hand this was plenty enough when I used the kk2 board and I flew alot with that setup.

I guess from a reliability point of view it might be better to use a ubec since there is only one point of failure compared with three becs, one from each ESC. If one fail…

From what I’ve read the Gopro can consume up to 1 A. So with that figure it wouldn’t be safe unlees you disconnect the charging lead to the gopro. In the manual of the Immersionrc vtx it was mentioned that amperage was not enough to support a gopro but I’ve successfully flown with it plenty of times. So I would think that with a fully charged gopro battery it does not draw 1 A.

I’m using a separate ubec both on the Rcexplorer tricopter and Fortis Airframes Titan.

Attachments:

1. 

   IMG_0607edited.jpg
   

[Aaron]

Thanks, I power the GoPro from the KK board and leave out the Gopro battery to save on weight.
Therefor im assuming two Afros are not be enough to power Gopro and servo

[hertz]

Drawing too much current from a regulator causes it to burn out, not brown out 🙂
Fly safe.

[Author]

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