Clarification on Navio 2 hardware setup

Navio / Edge Hardware
1

Hello
In the documentation for Navio 2 set-up, the following sentence is mentionned “only one ESC power wire (central) should be connected to Navio 2 servo rail, otherwise BECs built in ESCs will heat each other”

–> Does that mean I should cut the default wiring of the ESCs so that it only remains only one ESC with red cable plugged onto the servo rail? This seems a strange set-up to me.

–> Is there a direction to place the ESCs connectors on the servo rail (e.g. white or black on top)

–> Is there a recommended order to plug on the servo rail (1st = forward left engine, 2nd forward right, 3rd rear right, 4th rear left…)

Thanks very much for your answers!
Guillaume

2

Hi,

you should read through

Best regards

Sebastian

1 Like
3

Indeed, this is exactly what I did and the sentence I quote in my message is extracted from it.
I would appreciate a clarification if anybody knows the answer. Thanks very much in advance

4

Ok. Here we go:

  1. Each ESC has a BEC to provide 5V to the electronics/servos. there are two types of BECs, switching and linear. Switching BECs are more efficient, but they do not create a perfect DC voltage. Linear BECs are less effiecient, but they create less/no noise. If you connect multiple BECs in one circuit, they work against each other and probably overheat and shut down. Just pull the red wire out of the servo connector by lifting the little plastic strip with a sharp tool. No need to cut anything. Isolate the free connector with tape or shrinktube!

  2. Have a look at your Navio2 board, there should be little markings at the servo rail, showing the right direction to plug in your ESCs/servos. Bottom is black.

  3. http://copter.ardupilot.com/wiki/connect-escs-and-motors/

I hope this helps.

2 Likes
5

Here are diagrams that show motors in the right order and also how to plug them in.
http://docs.emlid.com/navio2/Navio-APM/typical-setup-schemes/

7

Anyone know if you can EMI shield the UBEC (Switching BEC) so that it will put out little/no noise. For example say put a carbon fiber cover on it?

8

Perfect explanation, thanks very much for your answer sebastian

9

use a independent bec (8 dólars) and escs opto, a handred times beter, no noise

10

Sorry, let me clarify. I have OPTO isolated ESC’s and I’m planning on using a separate BEC because they are better. If you use a Switching BEC it is more efficient but can produce noise, if you use a linear ESC you get lower efficiency but no noise. So my question is how can I isolate the noise from the Switching BEC. Ive seen some companies put some sort of ring around the wires, I’m not sure how this specifically works.

11

sorry , no idea.

12

The ring is called a ferrite ring. It is a low cost way to cancel out some of the noise a switching BEC produces.

13

Any idea if a small carbon fiber cover would also be good to isolate this noise. I know that that carbon fiber blocks rf signals so I would assume that it would work. Just looking for others input into the mater.

14

Sorry, how do you know the noise came from your BEC?

Usually came from your ESCs , Distribution Board and/or motors, from BEC… I never heard before.

MU Metal is the best for “isolation”; Carbon Fiber is “good” for RF not for mag field…

15

switching BEC’s use current switching in general similar to ESC’s except for phases etc. but the idea is by switching similar to an ESC does it creates noise. They also tend to be near radios, servos, and flight controllers so its a good idea to try to keep it isolated in my opinion. Its not that I am having any problems… just anticipation